".1<1.:).-. _. Mr. Sylvain Faille FILE I-QOSS!ER I

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1 ANAC Atlanta Corporate Headquarters 1'J30 Ed,1 Jone I:lridgc Road, Suite 200 Norcross rnfiinternational Phone March, 2014 ".1<1.:).-. _ '.. ')....'... ~ Mr. Sylvain Faille FILE I-QOSS!ER Canadian Nuclear Safety Commission I~EF~R8~D 280 Slater Street TO CNSC CCSN L iefere A Ottawa, ON KIP S9 Canada I Subject: NAC-LWT Cask, US NRC CoC 922 Highly Enriched Uranyl Nitrate Liquid (HEUNL) Amendment Dear Mr. Faille, NAC International (NAC) herewith provides an electronic copy of the proprietary and nonproprietary versions ofnac's response to the U.S. Nuclear Regulatory Commission's Request for Additional Information on the NAC-LWT HEUNL Arnendment Request on CD media. This documents are being provided to CNSC in support of the review ofnac's request for Canadian validation of the subject CoC for the shipment ofheunl Should you require additional documents, please feel free to contact me. Best Regards,,AJL--, L ~,L Anthony L Patko Director, Licensing Engineering Enclosure cc: Mr. Rajesh Garg - CNSC Mark Chapman - AECL ED

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4 February 2014 NAC-LWT Legal Weight Truck Cask System HEUNL RAI Response Package NON-PROPRIETARY VERSION Docket No Atlanta Corporate Headquarters: 3930 East Jones Bridge Road, Norcross, Georgia USA Phone , Fax , www nacintl.com

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11 Enclosure 1 RAI Responses and Supporting References No. 922 for NAC-LWT Cask NAC-LWT SAR, HEUNL Amendment ED Page 1 of 2

12 Enclosure 1 Contents 1. RAI responses 2. RAI supporting references (a). Report IAD-002, Revision 0, (RAI 2.2) (b). Report ASD-002, Revision 0, (RAIs 2., 4.1, and 7.8) (c). Calculation , Revision 0, (RAI 3.1) (d). Fire accident analysis data input/output files, (RAI 3.) ED Page 2 of 2

13 NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO THE UNITED STATES NUCLEAR REGULATORY COMMISSION REQUEST FOR ADDITIONAL INFORMATION FOR REVIEW OF THE CERTIFICATE OF COMPLIANCE NO. 922, REVISION FOR THE MODEL NO. NAC-LWT PACKAGE TO INCORPORATE HEUNL (TAC NO. L24708 DOCKET NO ) February 2014 Page 1 of 46

14 NAC-LWT Docket No TAC No. L24708 TABLE OF CONTENTS Page GENERAL INFORMATION EVALUATION... 3 STRUCTURAL EVALUATION... THERMAL EVALUATION CONTAINMENT EVALUATION CRITICALITY EVALUATION OPERATING PROCEDURES EVALUATION ACCEPTANCE AND MAINTENANCE TESTS EVALUATION Page 2 of 46

15 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION GENERAL INFORMATION EVALUATION 1.1 This information is needed to determine compliance with Title 10, Code of Federal Regulations (10 CFR) 71.71(c)(2). NAC International Response to General Information Evaluation RAI 1.1: Page 3 of 46

16 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION GENERAL INFORMATION EVALUATION 1.2 This information is needed to determine compliance with 10 CFR 71.33, 71.43, and NAC International Response to General Information Evaluation RAI 1.2: Page 4 of 46

17 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 STRUCTURAL EVALUATION 2.1 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION This information is necessary to determine compliance with 10 CFR (c), (c)(2). NAC International Response to Structural Evaluation RAI 2.1: Page of 46

18 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 STRUCTURAL EVALUATION 2.2 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION c. An ANSYS calculation was used to determine the effect of uranyl nitrate solution expansion on the material. Was this methodology validated, for example, by comparing the ANSYS results from a known material (i.e., water) and its corresponding coefficient of volume expansion? Provide this validation. d. Provide calculations (pressure, strain, etc.) that consider the volume expansion of the liquid from the lowest filling temperature to the maximum liquid temperature for normal conditions of transport and hypothetical accident conditions. This should be answered considering page states that the internal elements representing the HEUNL fluid were removed when determining the internal pressure. In addition: i. Page states, The container wall was also evaluated for potential buckling Did this analysis consider the expansion of the liquid from the lowest Page 6 of 46

19 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 filling temperature to the maximum normal conditions of transport fluid temperature (139 F)? ii. An analysis should show that the HEUNL container bolt covers, O-ring/O-ring groove, vessel boundary, quick disconnect valves, etc., can withstand the higher pressure from the expansion of the HEUNL at normal conditions of transport and hypothetical accident conditions, whether expansion as it freezes or the expansion of liquid during heating. The calculations should reflect the initial conditions (filling temperature, etc.) that result in the greatest expansion and resulting plastic strain. This information is needed to determine compliance with Title 10, Code of Federal Regulations (10 CFR) 71.33, 71.43, and NAC International Response to Structural Evaluation RAI 2.2: 2.2 a 2.2 b.i 2.2 b.ii Page 7 of 46

20 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L b.iii 2.2 c ANSYS has been validated to determine the stresses and deformation due to thermal expansion of materials. The HEUNL expansion upon freezing, which was provided as design input to the evaluation, was evaluated as a thermal expansion condition. This allowed the freezing condition to use the ANSYS option, which has been validated. 2.2 d Pressure calculations considering the temperature change as well as the effect of corrosion are presented in SAR Section d i The buckling calculation does not consider the increase in internal pressure from the lowest filling temperature to the maximum normal temperature. This is a conservative approach since any increase in internal pressure would produce an increase in the buckling load due to the stress stiffening effect. 2.2 d ii Page 8 of 46

21 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 STRUCTURAL EVALUATION 2.3 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION a. Page and Page indicate the solution may be diluted to achieve container fill capacity. Indicate the substance used to dilute the HEUNL solution. Are bounding concentrations used to determine the effect of radiolysis and liquid volume expansion? This information is needed to determine compliance with 10 CFR NAC International Response to Structural Evaluation RAI 2.3: Page 9 of 46

22 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 STRUCTURAL EVALUATION 2.4 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION This information is needed to determine compliance with 10 CFR and NAC International Response to Structural Evaluation RAI 2.4: 2.4 a Page 10 of 46

23 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L b Page 11 of 46

24 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION STRUCTURAL EVALUATION 2. This information is needed to determine compliance with 10 CFR 71.43(d). NAC International Response to Structural Evaluation RAI 2.: Page 12 of 46

25 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 a.) Chapter 1 of the SAR is modified to limit the lifetime of the container with HEUNL content, identified as HEUNL Container Content Fill Time, will be limited to 1 months. b.) Page 13 of 46

26 NAC-LWT Docket No TAC No. L24708 THERMAL EVALUATION NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION 3.1 Provide complete calculations in the SAR to show that the HEUNL container pressures for the cold and heat tests for normal conditions of transport and hypothetical accident conditions consider all possible sources of pressure on the HEUNL container. Show that these maximum pressures do not exceed the allowable values for the HEUNL container and the HEUNL container quick disconnect valves. The pressure calculations should clearly show all sources of pressure were considered, such as expansion of contents due to temperature, the change in volume of the HEUNL container due to temperature, gases initially present in the package, saturated vapor including water vapor from the contents, hydrogen or other gases resulting from thermal or radiation induced decomposition of materials such as water or plastics over 1 year, dynamic movement of the contents, the hydrostatic pressure due to the height of the fluid, etc. Accordingly, modify any other analysis, calculation packages, and portions of the application to ensure that the maximum HEUNL container pressures are used. a. Provide complete pressure calculations in Sections and of the SAR for the HEUNL container that take into account the change in volume of the HEUNL contents that completely fill the HEUNL container and the change in volume of the HEUNL container due to the temperature changes that occur over normal conditions of transport and hypothetical accident conditions. Pressure calculations for the HEUNL container during the cold and heat tests for normal conditions of transport and hypothetical accident conditions do not take into account the expansion of contents or the contraction of the HEUNL container during the normal conditions of transport cold test. Consider as temperature increases from ambient to normal conditions of transport hot or to hypothetical accident conditions how the contents will expand at a greater rate than the HEUNL container over the change in temperature. Ensure that the phenomenon that the HEUNL container will contract as temperature decreases and the contents will expand when frozen is accounted for when determining the pressure. The temperature changes, their impact on the change in volume of the HEUNL container and change in volume of the contents, should therefore be taken into account when calculating the pressure inside the HEUNL container. b. Provide the following pressure contributions when considering if a void space is present in the HEUNL container. The following contributions to pressure were not included in the SAR. Page 14 of 46

27 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 i. The pressure due to water vapor in the normal conditions of transport HEUNL container pressure calculation in Section of the SAR; complete calculations should be shown. ii. iii. The pressure due to the dynamic movement of the contents (sloshing) in normal conditions of transport and hypothetical accident conditions, which are not necessarily the same value, in Section of the SAR; complete calculations should be shown. A reduced void volume should also be addressed due to liquid contraction or expansion over the normal conditions of transport and hypothetical accident conditions temperature range. Although it has been stated in the application that the HEUNL containers will be fully loaded at 70 F, address through pressure calculations the presence of a void space that will be created as the ambient temperature decreases below 70 F during transport due to the thermal contraction of the contents relative to the HEUNL container. Also consider a small void volume that may be present at loading and how that void space will decrease in size as the ambient temperature increases above 70 F during transport due to the thermal expansion of the contents relative to the HEUNL container. If not loading at 70 F, a conservative initial filling temperature should be used for all calculations. A small void volume along with all sources of gases can cause significant pressure increases within the HEUNL containers. c. Provide the pressure contribution due to the hydrostatic pressure from the maximum height of the fluid. This information is needed to determine compliance with 10 CFR 71.43(c), (d), and (f), 71.71, 71.73, and 71.87(d). NAC International Response to Thermal Evaluation RAI 3.1: The system gas pressure calculation is provided as part of the RAI responses as a proprietary attachment (Calculation ). Pressures are updated in the SAR to correspond to the results of this calculation Page 1 of 46

28 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L b ii 3.2 c The estimated maximum hydrostatic pressure for the transport orientation is less than 0. psig which is a negligible increase in pressure. The maximum pressure for normal conditions is 8 psig but the canister was analyzed for 100 psig which bounds the increase due to hydrostatic pressure. Page 16 of 46

29 NAC-LWT Docket No TAC No. L24708 THERMAL EVALUATION NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION 3.2 Provide the maximum allowable pressure for the HEUNL container. Page of the SAR states that No HEUNL material will be released from the HEUNL container during any transport condition. This statement indicates that the HEUNL container will not fail, thus precluding contact between the HEUNL contents and the package containment boundary. To ensure that a pressure that develops within the HEUNL container is within the maximum allowable pressure for the HEUNL container and the HEUNL contents will not contact the containment boundary during any transport condition, the maximum allowable pressure for the HEUNL container should be provided. This information is needed to demonstrate compliance with 10 CFR and 10 CFR NAC International Response to Thermal Evaluation RAI 3.2: The maximum pressure in the canister for normal conditions of transport is 8 psig (72 psia) which was conservatively rounded up to 100 psig for the structural analysis. The maximum allowable pressure for normal conditions is 100 psig. Page 17 of 46

30 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION THERMAL EVALUATION 3.3 This information is needed to determine compliance with 10 CFR NAC International Response to Thermal Evaluation RAI 3.3: Page 18 of 46

31 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 THERMAL EVALUATION 3.4 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION This information is needed to determine compliance with 10 CFR and NAC International Response to Thermal Evaluation RAI 3.4: Note that Chapter 2 structural evaluations are based on a bounding pressure and not the actual pressures calculated within Chapter 3. Pressures used within Chapter 2 are the applied maximum pressures for normal and accident conditions of transport. There is no issue with higher values being used in Chapters 2 and 8. Page 19 of 46

32 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 THERMAL EVALUATION NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION 3. Address the following relevant to the hypothetical accident conditions temperature of the contents. a. Justify whether the analysis method described in Section of the SAR is appropriate for calculating the maximum temperature of the contents during the fire and post-fire cool down. Alternatively, run a fire and post-fire cool down analysis with the HEUNL containers and contents inside the NAC-LWT to calculate the maximum fire and post-fire temperatures of the contents and provide the hypothetical accident conditions analysis input and output files. In Section of the SAR the application describes an inner shell temperature difference from two different analyses (normal conditions of transport and hypothetical accident conditions) with completely different spent fuel contents compared to the contents of the application to calculate the maximum hypothetical accident conditions temperature of the HEUNL contents within an HEUNL container. The maximum inner shell temperature during the fire and post-fire cool down and the minimum inner shell temperature during normal conditions of transport hot conditions are used to calculate the maximum temperature increase of the HEUNL contents during hypothetical accident conditions. This appears to be an inappropriate comparison of contents and may not necessarily result in a conservative temperature for the HEUNL contents during the fire and post-fire cool down. The maximum HEUNL content temperature is then used to calculate the saturation pressure from steam tables. The staff notes that a slight change in calculated content temperature results in a large saturation pressure increase from water saturation tables. Many other calculations in the SAR are based on the maximum HEUNL content hypothetical accident conditions temperature and these values should be recalculated. b. Clarify whether the minimum inner shell temperature of 180 F described in Section of the SAR is truly a minimum temperature of the inner shell during normal conditions of transport hot conditions, or a minimum of two maximum temperatures each calculated using two different loading conditions. This information is needed to determine compliance with 10 CFR 71.73(c)(4). NAC International Response to Thermal Evaluation RAI 3.: Page 20 of 46

33 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 Page 21 of 46

34 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 THERMAL EVALUATION 3.6 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION Page 22 of 46

35 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 This information is needed to determine compliance with 10 CFR 71.43(c) and (f), 71.1(a)(1) and (2). NAC International Response to Thermal Evaluation RAI 3.6: Page 23 of 46

36 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 THERMAL EVALUATION 3.7 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION This information is needed to demonstrate compliance with 10 CFR and NAC International Response to Thermal Evaluation RAI 3.7: The proper text is as stated during normal and accident conditions. The SAR is corrected. Page 24 of 46

37 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION THERMAL EVALUATION 3.8 This information is needed to determine compliance with 10 CFR 71.43(f). NAC International Response to Thermal Evaluation RAI 3.8: Page 2 of 46

38 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION THERMAL EVALUATION 3.9 Describe the method used to determine the total decay heat and the margin of error associated with the value. Section 3.1 of the SAR states that the total decay heat in the NAC-LWT is Watts, the method used to determine the value was not addressed and the error associated with the value was not provided. This information is needed to determine compliance with 10 CFR 71.33(b)(7). NAC International Response to Thermal Evaluation RAI 3.9: The same limitation applies to the radionuclide gamma emitter content (Curie/liter) and uranium ( 23 U) content (g/liter) specified. For use in pressure evaluations (gas generation using deposited energy), the conservative heat load applied in the thermal analysis is reduced to a maximum value 0.02W/liter. Page 26 of 46

39 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 CONTAINMENT EVALUATION 4.1 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION a. b. c. d. Page 27 of 46

40 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 This information is needed to determine compliance with 10 CFR 71.33, 71.3, 71.43, and NAC International Response to Containment Evaluation RAI 4.1: 4.1a 4-1b Page 28 of 46

41 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L c 4.1d 4.1e The container pressure calculation, including the excel file that implements the calculation, is provided with the RAI responses. 4.1f The container pressure calculation, including the excel file that implements the calculation, is provided with the RAI responses. 4.1g Page 29 of 46

42 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 CONTAINMENT EVALUATION NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION 4.2 Provide further information on the void space within the HEUNL container. Page and page state: Fill capacity is defined as the point when material reaches the vent port during fill operations. Likewise, page states that there is a minimal air void. The void headspace should be provided for vertical and horizontal HEUNL containers. Note question 1 in Chapter 7 that requests justification for adequate space, or other specified provisions, during loading for the expansion of the HEUNL. This information is needed to determine compliance with 10 CFR 71.33, 71.1, and NAC International Response to Containment Evaluation RAI 4.2: Page 30 of 46

43 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 CONTAINMENT EVALUATION 4.3 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION This information is needed to determine compliance with 10 CFR 71.33, 71.43, and NAC International Response to Containment Evaluation RAI 4.3: Page 31 of 46

44 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 CRITICALITY EVALUATION 6.1 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION This information is needed to determine compliance with 10 CFR 71. and NAC International Response to Criticality Evaluation RAI 6.1: The submitted analysis considers the measured concentrations for actinides of the processed material. As a response to the RAI, NAC generated an additional analysis that increases the evaluated enrichment to the target material maximum initial, unirradiated, enrichment of 93.4 wt. %. The partial density of 23 U is also increased from 7.20 g/l to 7.40 g/l. All results remain subcritical (see Section and Tables through -23). Section has been updated for the maximum reactivity output file. Sections 6.1 and , and Table were updated accordingly. Page 32 of 46

45 NAC-LWT Docket No TAC No. L24708 CRITICALITY EVALUATION NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION 6.2 Clarify the cross section sets used for the validation and for analyses. SAR Section states that the ENDF/B-VII cross-section set is used for analyses. However, Section and elsewhere states that the ENDF/B-VI cross-section set is used for validation. Also, ENDF/B-VI is used for some of the materials in analyses (e.g., natural silicon). Explain these inconsistencies. This information is needed to determine compliance with 10 CFR 71. and NAC International Response to Criticality Evaluation RAI 6.2: The validation applied for the HEUNL evaluation is Section 6..4 MCNP Criticality Benchmarks for Uranyl Nitrates. In the submitted analysis, this is noted in Sections 6.1, , and Other benchmarks (Section and elsewhere) are not utilized in the HEUNL evaluation. The cross-section sets used for the validation are ENDF/B-VII when available and the latest, most applicable set otherwise (ENDF/B-VI, ENDF/B-V, etc.). Section is corrected from ENDF/B-VI to ENDF/B-VII. Text is added to Section to clarify this and the list of validated cross-section libraries is provided in Table Text is added in Sections and for the MCNP Validated Libraries to clarify that libraries validated in the HEUNL validation are applied. A list of the evaluated libraries for the HEUNL evaluation is provided in Table Additional Revision: Table is revised to correct a copy/paste error that incorrectly listed number densities for the materials. Page 33 of 46

46 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.1 Show how full HEUNL containers will meet 10 CFR 71.87(d) which states, Before each shipment of licensed material, the licensee shall ensure that the package with its contents satisfies the applicable requirements of this part and of the license. The licensee shall determine that... (d) Any system for containing liquid is adequately sealed and has adequate space or other specified provision for expansion of the liquid. A sealed HEUNL container that is completely filled does not have adequate space or other specified provision for expansion of the liquid. A sealed HEUNL container when frozen with HEUNL contents that was filled at 70 F does not have adequate space or other specified provision for expansion of the liquid. Consider a sealed rigid container (constant volume) that is completely full of liquid (constant mass); this is an isochoric process (or constant specific volume). Although a rigid container is an idealized case, Reference 1 can be used to show the container pressure that can be reached within a sealed rigid container loaded full of water that has a density of kg/m 3 (the density of water at 70 F) when heated or cooled based on an isochoric process. In an isochoric process, relatively small deviations from the loading temperature result in very large pressure changes and uncontrollable pressurization as contents are heated. Note the pressure generated in an isochoric process is excluding any combustible gas generation that should also be considered which could create additional pressure. Uncontrollable pressurization of the HEUNL container could lead to failure of the HEUNL container and could impact the containment boundary. Therefore ensure through calculations that there is adequate space for expansion of the HEUNL contents in a sealed container, or other specified provision to protect against over pressurization, and that these design features are implemented in the operating procedures. This information is needed to determine compliance with 10 CFR 71.43(c) and (f), and 71.87(d). Reference 1: E.W. Lemmon, M.O. Mclinden and D. G. Friend, Thermophysical Properties of Fluid Systems, in NIST Chemistry WebBook, NIST Standard Reference Database Number 69, Eds. P.J. Linstrom and W.G. Mallard, National Institute of Standards and Technology, Gaithersburg, MD, 20899, NAC International Response to Operating Procedures Evaluation RAI 7.1: Page 34 of 46

47 NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.2 Revise Chapter 7 to provide the following additional information on the HEUNL loading and unloading procedures. a. The unloading procedure is based on the horizontal unloading of the HEUNL container. Procedures for vertical loading and unloading should be provided or vertical loading and unloading not be a specified option. b. Figure shows an HEUNL container with a drain tube. It should be specified in Chapter 7 that the HEUNL container with the drain tube is for vertical filling and draining. Likewise, Chapter 7 should indicate that the HEUNL container without the drain tube is to be used for horizontal filling and draining. This information is needed to determine compliance with 10 CFR and NAC International Response to Operating Procedures Evaluation RAI 7.2: The operating procedures in Chapter 7 have been revised to specifically address both vertical and horizontal loading and unloading of both the NAC-LWT cask, and the vertical filling of HEUNL container. The emptying of the HEUNL container at the receiving facility will be governed by sitespecific procedures prepared in accordance with the requirements to empty and flush the HEUNL container in accordance with the commitments defined in Chapters 7 and 8 of the SAR. Page 3 of 46

48 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.3 Clarify that the filling procedure prevents overfilling and over-pressurizing of the HEUNL container. There is no indication from step 11 of Section that measures are taken to prevent overfilling and, hence, over-pressurization of the HEUNL container during the fill process. This should be addressed in the loading procedure. This information is needed to determine compliance with 10 CFR 71.87(d) and (f). NAC International Response to Operating Procedures Evaluation RAI 7.3: Page 36 of 46

49 NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.4 Clarify steps 6 and 22 in the operating procedures in Section to specify that alternate vent and drain port covers must be used during transport of the HEUNL container. Per Chapter 4, shipment of HEUNL containers will use the alternate vent and drain port covers. For clarity, this should be specified in steps 6 and 22 of Section This information is needed to determine compliance with 10 CFR 71.87(c). NAC International Response to Operating Procedures Evaluation RAI 7.4: The operating procedures in Chapter 7 have been revised to include specific instructions to require the use and testing of the Alternate port covers, which are provided with Viton O-rings. Page 37 of 46

50 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7. Provide the following details of the vacuum rate-of-rise test described in step 12 of Section a. Clarify the valve annulus that is to be evacuated. Is this the space between component 19 and component 20 O-rings listed in Drawing No or is it at the component 17 nipple? Where is the vacuum and vacuum gauge attached? Further explanations in the procedure should be provided. b. Provide the basis for detecting a leakage rate of 1E-3 ref-cm 3 /sec, the test sensitivity, and the instruction for measuring the leakage rate. For example, the American National Standards Institute (ANSI) in ANSI N , Radioactive Materials - Leakage Tests on Packages for Shipment, provides guidance, acceptable sensitivity, and equations for performing a pressure rise test (Section B.12, B.14, A..2, etc.). c. Step b indicates the vacuum pump should be isolated. It is recognized that a running vacuum pump can pull vacuum across closed valves. The procedure should provide instruction to physically remove or power-off the vacuum pump. This information is needed to determine compliance with 10 CFR 71.87(d). NAC International Response to Operating Procedures Evaluation RAI 7.: The operating procedures have been revised to clearly define the assembly pressure rise and gas pressure drop tests performed to verify proper closure of the HEUNL container lid. with a Viton O-ring seal. In addition, the HEUNL container pressure boundary will be subjected to both a hydrostatic test per the ASME Code, Section III, Subsection NB, NB-6200, and a helium leakage test in accordance with ANSI N14. to leaktight criteria to confirm the leaktight integrity of the container. These acceptance tests are detailed in Section of the SAR. During filling operations, the container lid closure and assembly will be confirmed by the performance of a gas pressure drop test of the container lid inner O-ring to a sensitivity of 1 x 10-3 ref-cm 3 /s. If the port plug has been removed since the last assembly leakage test, a separate gas pressure rise test will be performed. All testing shall be performed in accordance with ANSI N14. requirements. The revised procedures in Section detail the specific requirements for the testing sequence and acceptance criteria. It is noted that if a HEUNL container pressure boundary O-ring seal or component requires replacement, the container shall be taken out of service until the seal and/or component can be replaced and retested to leaktight criteria as described in Section Page 38 of 46

51 NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.6 Provide the following details of the pressure-drop test described in step 24 of Section a. The acceptable test leakage rate and sensitivity should be provided. b. Provide the basis for detecting the acceptable leakage rate, test sensitivity, and instruction for measuring the leakage rate. For example, ANSI N14. provides guidance, acceptable sensitivity, and equations for performing a pressure-drop test (Section 8.11, 8.14, A..1, etc.). c. Step c indicates the gas supply should be isolated. It is recognized that gas can leak across closed valves. The procedure should provide instruction to physically remove the gas supply. This information is needed to determine compliance with 10 CFR NAC International Response to Operating Procedures Evaluation RAI 7.6: The test procedures performed on each HEUNL container after material filling operations are described in detail in the Chapter 7 operating procedures and in the response to RAI 7.. Page 39 of 46

52 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.7 Provide the ambient temperature, temperature of the HEUNL containers, and temperature of the HEUNL diluted contents during loading of the HEUNL containers in Chapter 7 of the SAR. Many analyses throughout Chapters 2, 3, and 4 of the SAR assume an ambient temperature of 70 F during loading, yet this temperature is not specified within the loading procedures. The temperature of the HEUNL container and HEUNL diluted contents could also impact the quantity of material that fills the HEUNL containers and the void volume with in the container once steady state temperatures are reached. These temperatures should be addressed in the loading procedures. This information is needed to determine compliance with 10 CFR 71.3(c), and NAC International Response to Operating Procedures Evaluation RAI 7.7: The operating procedures in Chapter 7 have been revised to specify that the surface temperature of the empty HEUNL container will be confirmed to be at an acceptable temperature (between 60 F and 90 F) for material loading as verified with a surface pyrometer or equivalent instrument prior to filling. Similarly, the HEUNL container will be confirmed to be at an acceptable temperature for material unloading between 60 F and 90 F as verified with a surface pyrometer or equivalent instrument prior to emptying. Page 40 of 46

53 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.8 Address the possibility of a rapid release of hydrogen gas that could be dissolved in the HEUNL content solution in a full HEUNL container during unloading in Section of the SAR. Section of the SAR, Procedure for Unloading of HEUNL Contents, does not address the possibility of a rapid release of hydrogen gas that could be dissolved within the HEUNL content solution that fills the HEUNL container. The procedures should consider a rapid release of hydrogen gas could result in a highly flammable situation and an unexpected high pressure. This information is needed to determine compliance with 10 CFR 71.3(c) and NAC International Response to Operating Procedures Evaluation RAI 7.8: Nevertheless appropriate cautions will be incorporated into the site-specific HEUNL emptying procedure to address the potential for gas and/or liquid release (including hydrogen) from the solution during the HEUNL container material emptying operations following transport. In addition, Chapter 1 has been revised to specify the maximum transport time to be incorporated into the Certificate of Compliance of 3 months (e.g., 90 days). Page 41 of 46

54 NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.9 Address whether a quantity of time, an ambient temperature, an HEUNL container temperature, or other parameters should be specified in Section of the SAR so the HEUNL contents will return to the as loaded state before they are unloaded. Section of the SAR does not address the possibility that the contents may need to return to the as loaded state before unloading, or what surveys are necessary to ensure the contents have returned to the as loaded state. Not returning the contents to the as loaded state before unloading could result in the rapid depressurization of the container, or rapid release of flammable gases. This information is needed to determine compliance with 10 CFR 71.3(c) and NAC International Response to Operating Procedures Evaluation RAI 7.9: Operational procedures provided in Chapter 7 have been revised to account for the NAC-LWT cask and HEUNL containers being at a higher than loaded (one atmosphere) pressure following transport. The operating procedures also specify that the HEUNL container temperature is confirmed to be between 60 F and 90 F which is the acceptable temperature range for material emptying operations. The container temperatures will be verified with a pyrometer or equivalent instrument. Connecting systems provided to initially vent the vent quick disconnect will be designed to account for the maximum normal condition HEUNL container pressure at arrival at the receiving facility. Page 42 of 46

55 NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION OPERATING PROCEDURES EVALUATION 7.10 Identify any inspection or other actions necessary to address the pressure and stresses on the drain pipe due to an HEUNL container full of liquid or frozen contents, an HEUNL container partially full of liquid or frozen contents taking into account the freezing process as well as dynamic movement of contents like sloshing or liquid surge pressure that could occur during filling or transport. Failure of the drain pipe could cause problems with vertical unloading the HEUNL contents leading to a delay in unloading. This information is needed to determine compliance with 10 CFR 71.3(c) and NAC International Response to Operating Procedures Evaluation RAI 7.10: The design of the HEUNL container allows the installation of a drain tube through the vent port (i.e., removal of the vent tube/siphon and installation of a new drain tube welded to a spare Snap-tite nipple) in order to properly empty the container in the event that a drain tube is damaged or disconnected during transport. Page 43 of 46

56 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ACCEPTANCE AND MAINTENANCE TESTS EVALUATION 8.1 Justify the basis of 0 fill/drain cycles that appears in Section of the SAR and how it relates to the expansion and contraction that a full HEUNL container (with liquid or frozen contents) will go through during normal conditions of transport. a. Based on the thermal expansion and contraction of the full contents due to varying ambient conditions and solar insolation that would also vary throughout the day, a full HEUNL container may go through multiple expansion and contraction cycles during one transport. It has not been shown how 0 fill/drain cycles relates to the actual conditions that a package will go through during transport. Consider how Section 8.2 and Table should be modified based on the thermal expansion and contraction of the full contents. b. The basis for the 0 fill/drain cycle periodic hydrostatic test (Section ) of the HEUNL container should be provided. The basis should reflect phenomena that can affect the integrity of the container, including high stresses (due to the expansion of the liquid during transport), corrosion rate, etc. This information is needed to determine compliance with 10 CFR and 71.43(d). NAC International Response to Acceptance and Maintenance Tests Evaluation RAI 8.1: A 1-month operational limit identified as HEUNL Container Content Fill Time will be recorded and maintained for each individual container by identification number. HEUNL Container Content Fill Time is determined from the time of completion of HEUNL material filling operations into the container through completion of the HEUNL material emptying and flushing operations at the receiving facility. In addition, the maximum allowable transport time for a loaded NAC-LWT cask is limited to 3 months, and prior to filling, the remaining HEUNL Container Content Fill Time of a specific container shall be confirmed to be 3 months prior to transport. Following empting operations the containers are flushed with demineralized water to minimize corrosion of empty containers. Page 44 of 46

57 NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ACCEPTANCE AND MAINTENANCE TESTS EVALUATION 8.2 Ensure that the hydrostatic test on the HEUNL container is appropriate for the pressures generated in the HEUNL container. Ensure consistency with items 1 and 2 in the thermal evaluation above. The hydrostatic test in Section of the SAR should be performed in accordance with the ASME Boiler and Pressure Vessel Code Section III, Subsection NB, to 1.2 times the design pressure. The design pressure should bound the pressure generated in the HEUNL container. Note see item 1 in the Thermal Evaluation section above. This information is needed to determine compliance with 10 CFR 71.43(c) and (f), 71.71, 71.73, and 71.87(d). NAC International Response to Acceptance and Maintenance Tests Evaluation RAI 8.2: The design pressure per Chapter 2 of the SAR is 100 psia. Hydrostatic testing of the HEUNL container in accordance with the ASME Code, Section III, Subsection NB, NB-6200 to a pressure of 140 psig (1.2 times design pressure) has been incorporated into Chapter 8, Section , including definition of the testing requirements, HEUNL container pressure boundary, and test acceptance criteria. Page 4 of 46

58 NAC PROPRIETARY INFORMATION REMOVED NAC-LWT Docket No TAC No. L24708 NAC INTERNATIONAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ACCEPTANCE AND MAINTENANCE TESTS EVALUATION 8.3 Address the following relevant to the dimensions of the HEUNL container. a. Resolve how an HEUNL container that has been shown in the structural analysis to plastically deform during normal conditions of transport will match the certification drawings which will be referenced in the certificate of compliance which do not show dimensions for an HEUNL container that has been plastically deformed. b. Justify that a visual inspection and axial measurement of the HEUNL inner container, as specified in Section 8.2, is sufficient to ensure that containers that do not meet the drawings are not used in subsequent transports. c. Address whether the axial gauge check value in Section 8.2 of the SAR should be modified based on item 6 in the thermal evaluation and whether a radial gauge check should be added to Section 8.2 of the SAR based on item 6 in the thermal evaluation. This information is needed to determine compliance with 10 CFR 71.87(b). NAC International Response to Acceptance and Maintenance Tests Evaluation RAI 8.3: Page 46 of 46

59 PROPRIETARY INFORMATION REMOVED IAD-002, Rev. 0 WITHHELD IN ITS ENTIRETY PER 10 CFR 2.390

60 PROPRIETARY INFORMATION REMOVED ASD-002, Rev. 0 WITHHELD IN ITS ENTIRETY PER 10 CFR 2.390

61 PROPRIETARY CALCULATION , REV. 0 WITHHELD IN ITS ENTIRETY PER 10 CFR 2.390

62 Enclosure 2 List of Changes NAC-LWT SAR, HEUNL Amendment RAI Responses ED Page 1 of

63 List of Changes, NAC-LWT SAR, Note: The List of Effective Pages and the Chapter Tables of Contents, including the List of Figures, the List of Tables, and the List of Drawings, were revised as needed to incorporate the following changes. Chapter 1 Page 1-4, modified third bullet in Table Page 1.1-2, modified sixth bullet and last paragraph of page. Page 1.2-6, modified item number 21 of subsection Page , modified subsection , HEUNL Containers, throughout. Page , updated Figure Page 1.2-3, modified Table , HEUNL Characteristics, and footnote number 2. Chapter 2 Page , modified Table Page , modified Table Page , modified first and last paragraphs of subsection , HEUNL Container. Page , text flow. Pages thru (middle of page), numerous changes throughout subsections and Pages (bottom of page) thru , added new subsections and , and renumbered subsection Page , modified the minimum margin of safety in subsection Pages thru , made numerous changes throughout subsection , added new subsection and renumbered subsection Chapter 3 Page 3.1-1, modified last sentence of second paragraph of Section 3.1. Page , modified last paragraph on page, in subsection Pages thru 3.4-7, modified subsections , Cask Containment and , HEUNL Container. Pages thru 3.-14, modified subsection , Evaluation of HEUNL. Page 3.-1 thru 3.-18, text flow. Page 3.-19, modified subsection , Cask Containment. Page 3.-20, modified subsection , HEUNL Container. Pages thru 3.-34, text flow. Pages 3.-3 thru 3.-38, added new figures thru Pages thru 3.-42, text flow. ED Page 2 of

64 List of Changes, NAC-LWT SAR, (cont d) Chapter 4 Page 4.2-2, modified last paragraph of Section 4.2.2, Pressurization of Containment Vessel. Pages thru 4.2-4, text flow. Page 4.3-4, modified subsection , HEUNL Containment. Pages thru 4.-43, modified subsection , Pressurization and , Flammability throughout. Chapter Page.1.1-1, modified last bullet on page under subsection.1.1. Chapter 6 Page 6.1-, modified last paragraph on page. Page thru , removed changes that were added for Revision LWT-13B, reverting text back to as it was in Revision 41. Page , removed changes that were added in Revision LWT-13B, reverting the table and notes back to as they were in Revision 41. Page , modified last sentence of first paragraph in subsection Page , modified second paragraph of subsection Page , inserted new Table , Highly Enriched Uranyl Nitrates Validated Cross-Section Libraries. Page , modified second paragraph of subsection Page , modified second paragraph of subsection , and the second sentence of the fifth paragraph under the subheading, Description of Calculational Models. Page , modified third and fourth paragraphs of subsection Page , modified the second paragraph under subheading, 10 CFR 71. Uranyl Nitrate H/U Study. Page , text flow. Page , added new paragraph under subheading, MCNP Validated Libraries, and modified the second paragraph of the same section. Page , text flow. Page thru , made an editorial correction to the first paragraph under subheading, Water Reflector and Canister Dimensions ; added two new paragraphs under subheading Increased Enrichment Evaluation ; added new third paragraph to the end of subsection ; and modified subsection Pages thru , text flow. ED Page 3 of

65 List of Changes, NAC-LWT SAR, (cont d) Page , modified Table , HEUNL Analysis Compositions and Number Densities. Pages thru , text flow. Pages , modified Table , causing text flow. Pages thru , added new Table , HEUNL Evaluated Libraries, Table , Evaluated HEUNL Properties for Increased Enrichment, Table , HEUNL Maximum Reactivity per 10 CFR 71. for Increased Enrichment, and Table , HEUNL Maximum Reactivity per 10 CFR 71.9 for Increased Enrichment : Chapter 6 Appendices Page , modified the text in Section Pages thru , replaced the output data in Figure Chapter 7 Page 7.1-1, modified the sixth paragraph of Section 7, Operating Procedures. Page 7.1-2, modified the end of the second paragraph of Section 7.1, Procedures for Loading Packages. Page 7.1-3, text flow. Pages thru 7.1-8, modified the Section , Procedure for Dry Loading the HEUNL Contents into the NAC-LWT Cask heading title and section text. Pages (top of page) thru , added new subsection heading , Vertical Dry Loading of HEUNL Containers into the NAC-LWT and modified the steps throughout the section. Pages (bottom of page) thru (top of page), added new subsection , Horizontal Dry Loading of HEUNL Containers into the NAC-LWT, and the steps that follow. Pages thru , added new Section , Procedures for the Loading of HEUNL Contents into HEUNL Containers, and the included subsections thru Pages thru (bottom of page), modified Section 7.2.7, Procedure for Unloading of HEUNL Contents, including adding new subsection heading , Vertically Dry Unloading of HEUNL Containers into the NAC-LWT, and modified the steps that follow. Pages (bottom of page) thru (top of page), added new subsection , Horizontally Dry Unloading of HEUNL Containers from the NAC-LWT, and the steps that follow. Pages , added new Section 7.2.8, Procedures for the Unloading of HEUNL Material from HEUNL Containers. ED Page 4 of

66 List of Changes, NAC-LWT SAR, (cont d) Chapter 8 Page 8.1-1, modified second paragraph of Section 8, Acceptance Tests and Maintenance Program. Page 8.1-4, modified Step of Section , Closure Lid Leakage Rate Test. Pages thru , modified subsection , HEUNL Container, throughout. Pages thru , text flow changes. Page 8.2-2, modified the 2 nd full paragraph (last of section 8.2). Page 8.2-3, text flow changes. Page 8.2-, modified the section, HEUNL Container, of Table Chapter 9 No changes ED Page of

67 Enclosure 3 List of Drawing Changes NAC-LWT SAR, HEUNL Amendment ED Page 1 of 4

68 NAC PROPRIETARY INFORMATION REMOVED List of Drawing Changes, NAC-LWT SAR, Drawing , Revision 2P Drawing , Revision 2P ED Page 2 of 4

69 NAC PROPRIETARY INFORMATION REMOVED ED Page 3 of 4

70 NAC PROPRIETARY INFORMATION REMOVED ED Page 4 of 4

71 Enclosure 4 Supporting Calculations No. 922 for NAC-LWT Cask NAC-LWT SAR, HEUNL Amendment ED Page 1 of 2

72 Enclosure 4 Contents 1. Calculation , Revision 2 2. Calculation , Revision 0 ED Page 2 of 2

73 PROPRIETARY CALCULATION , REV. 2 WITHHELD IN ITS ENTIRETY PER 10 CFR 2.390

74 PROPRIETARY CALCULATION , REV. 0 WITHHELD IN ITS ENTIRETY PER 10 CFR 2.390

75 Enclosure Proposed Changes for Revision 9 of Certificate of Compliance No. 922 for NAC-LWT Cask NAC-LWT SAR, HEUNL Amendment ED Page 1 of 3

76 Drawings (new) CoC Page 4 of 33: LWT , Rev. 2P & 0NP LWT , Rev. 2P & 0NP LWT , Rev. 1P & 0NP LWT , Rev. 1P & 0NP LWT Transport Cask Assembly, HEUNL Contents Container Assembly, HEUNL Container Spacer, HEUNL Container Guide, HEUNL CoC Sections (new) CoC Page 19 of 31:.(b)(1) Type and form of material (continued) (xx) HEUNL as specified below: Parameter Maximum HEUNL payload per Container Maximum Cask Heat Load Maximum Per Container Heat Load Maximum HEUNL Heat Load Maximum Curie Content (gamma emitters) Maximum 23 U content Maximum 23 U enrichment Liquid HEU 64.3 L (17.0 gal) W 3.22 W 0.02 W/L 9.0 Ci/L 7.4 gu/l 93.4 wt% CoC Page 27 of 31:.(b)(2) Maximum quantity of material per package (continued) (xxi) For the HEUNL described in Item.(b)(1)(xx): Up to 64.3 L (17.0 gal) of HEUNL may be loaded per container. A total of 4 containers per cask shall be loaded. Full, partially filled and empty containers shall be in accordance with NAC Drawing Nos , and Cask configuration to be in accordance with NAC Drawing No ED Page 2 of 3

77 CoC Sections (revised) CoC Page 29 of 31: (c) Criticality Safety Index (CSI) For HEUNL described in.(b)(1)(xx) and 0.0 limited in.(b)(2)(xxi) CoC Page 30 and 31 of For shipment of HEUNL contents: (a) The maximum cumulative time an HEUNL container shall contain HEUNL solution is 1 months (b) The maximum one-way trip time the NAC-LWT shall be in transport with an HEUNL payload is 3 months (c) No HEUNL container shall be filled and used in transport when its cumulative time containing HEUNL solution is greater than 12 months 17. For shipment of non-fissile contents, with fissile content in the package not exceeding Type A quantity, and qualifying as a fissile exempt quantity under 10 CFR 71.1, the Model No. NAC-LWT shall be designated as Type B(U)F-96, with package identification number USA/922/B(U) Transport by air is not authorized. 19. The packaged authorized by this certificate is hereby approved for use under the general license provisions of 10 CFR Revision 8 and 9 of this certificate may be used until October 31, 2014 and February 28, 201, respectively. REFERENCES NAC International, Inc., application dated June 18, NAC International, Inc., supplements dated February 3, March 2, and May 24, October 26, and December, 2012; January 14, February 14, July 19 (two supplements), and October 18, 2013; December 28, 2012, March 14, 2013 and February TBD, ED Page 3 of 3

78 Enclosure 6 SAR Page Changes and LOEP No. 922 for NAC-LWT Cask NAC-LWT SAR, HEUNL Amendment ED Page 1 of 1

79 February 2014 NAC-LWT Legal Weight Truck Cask System SAFETY ANALYSIS REPORT NON-PROPRIETARY VERSION Docket No Atlanta Corporate Headquarters: 3930 East Jones Bridge Road, Norcross, Georgia USA Phone , Fax , www nacintl.com

80 NAC-LWT Cask SAR February 2014 LIST OF EFFECTIVE PAGES Chapter 1 1-i... Revision 41 1-ii... Revision LWT-12E 1-iii... Revision 41 1-iv thru Revision LWT-12E Revision Revision Revision LWT-12E Revision Revision LWT-12E thru Revision Revision LWT-12E thru Revision thru Revision thru Revision LWT-12E Revision Revision Revision drawings in the Chapter 1 List of Drawings Chapter 1 Appendices 1-A through 1-G Chapter 2 2-i... Revision 41 2-ii... Revision LWT-12E 2-iii... 2-iv thru 2-vi... Revision LWT-12E 2-vii... Revision 41 2-viii thru 2-xii... 2-xiii thru 2-xxiv... Revision Revision thru Revision thru Revision thru Revision Revision Revision Revision thru Revision Revision Revision Revision Revision Revision Revision Revision thru Revision thru Revision thru Revision thru Revision Revision Revision thru Revision Revision thru Revision Revision Revision thru Revision thru Revision Revision LWT-13B thru Revision 41 Page 1 of 4

81 NAC-LWT Cask SAR February 2014 LIST OF EFFECTIVE PAGES (Continued) thru Revision LWT-13B thru Revision thru Revision thru Revision thru Revision Revision thru Revision thru Revision Revision LWT-12E thru Revision Revision LWT-12E thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision 41 Chapter 3 3-i thru 3-iii... 3-iv... Revision LWT-12E 3-v Revision LWT-12E thru Revision Revision thru Revision Revision LWT-12E thru Revision LWT-12E thru thru Revision LWT-12E 3.-1 thru Revision thru thru Revision 41 Chapter 4 4-i thru 4-ii... Revision LWT-13B 4-iii... Revision LWT-12E Revision LWT-13B Revision thru Revision LWT-13B Revision LWT-12E thru thru Revision Revision thru Revision thru Revision 14B Chapter -i... Revision LWT-12E -ii thru -iv... Revision 41 -v thru -vi... Revision LWT-12E -vii thru -xi... Revision 41 -xii... Revision LWT-12E -1 thru Revision 41 Page 2 of 4

82 NAC-LWT Cask SAR February 2014 LIST OF EFFECTIVE PAGES (Continued) Revision LWT-12E thru Revision Revision LWT-12E thru Revision thru Revision LWT-12E thru Revision thru Revision Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision LWT-12E thru Revision 41 Chapter 6 6-i thru 6-ii... Revision LWT-12E 6-iii thru 6-iv... Revision 41 6-v... Revision LWT-12E 6-vi... 6-vii... Revision LWT-12E 6-viii thru 6-xiv... Revision 41 6-xv thru 6-xvi Revision LWT-12E thru Revision Revision thru Revision thru Revision thru Revision Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision 41 Page 3 of 4

83 NAC-LWT Cask SAR February 2014 LIST OF EFFECTIVE PAGES (Continued) thru Revision thru Revision thru Revision thru Revision thru Revision Revision LWT-12E thru Revision LWT-12E thru Revision Revision LWT-12E thru Revision thru thru Revision LWT-12E Appendix i... Revision LWT-12E 6.6-ii... Revision iii... Revision LWT-12E Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Revision thru Chapter 7 7-i... 7-ii... Revision thru thru Revision thru thru Revision thru thru Revision 41 Chapter 8 8-i... Revision LWT-12E thru Revision thru Revision thru Revision thru Revision thru Revision 41 Chapter 9 9-i... Revision thru Revision 41 Page 4 of 4

84 NAC-LWT Cask SAR April 2010 Revision 41 List of Drawings Rev 7 Legal Weight Truck Transport Cask Assembly Sheets 1 2 Rev 24 NAC-LWT Cask Body Assembly Sheets 1 6 Rev 6* NAC-LWT Transport Cask Body Sheets 1 7 Rev 22 NAC-LWT Transport Cask Body Rev 10 NAC-LWT Transport Cask Lid Assembly Sheets 1 2 Rev 10 NAC-LWT Transport Cask Upper Impact Limiter Rev 10 NAC-LWT Transport Cask Lower Impact Limiter Sheets 1 Rev 18 NAC-LWT Transport Cask Parts Detail Rev 2 NAC-LWT PWR Basket Spacer Sheets 1 2 Rev 8 NAC-LWT Cask PWR Basket Rev 2 NAC-LWT BWR Fuel Basket Assembly Rev 3 NAC-LWT Metal Fuel Basket Assembly Rev 6 Weldment, 7 Element Basket, 42 MTR Fuel Base Module Rev 6 Weldment, 7 Element Basket, 42 MTR Fuel Intermediate Module Rev 6 Weldment, 7 Element Basket, 42 MTR Fuel Top Module Rev 3 Legal Weight Truck Transport Cask Assembly, 42 MTR Element Rev 6 Weldment, 7 Element Basket, 28 MTR Fuel Base Module Rev 6 Weldment, 7 Element Basket, 28 MTR Fuel Intermediate Module Rev 6 Weldment, 7 Element Basket, 28 MTR Fuel Top Module Rev 3 Legal Weight Truck Transport Cask Assembly, 28 MTR Element Rev 6 Weldment, 7 Cell Basket, TRIGA Fuel Base Module Rev 6 Weldment, 7 Cell Basket, TRIGA Fuel Intermediate Module Rev 6 Weldment, 7 Cell Basket, TRIGA Fuel Top Module Rev 6 Legal Weight Truck Transport Cask Assy, 120 TRIGA Fuel Elements or 480 Cluster Rods Rev 4 Weldment, 7 Cell Poison Basket, TRIGA Fuel Base Module Rev 4 Weldment, 7 Cell Poison Basket, TRIGA Fuel Intermediate Module Rev 4 Weldment, 7 Cell Poison Basket, TRIGA Fuel Top Module Rev 0 Spacer, LWT Cask Assembly, TRIGA Fuel Rev 4 Legal Weight Truck Transport Cask Assy, 140 TRIGA Elements Rev 1 Axial Fuel and Cell Block Spacers, MTR and TRIGA Fuel Baskets, NAC-LWT Cask Rev 1 Assembly, Sealed Failed Fuel Can, TRIGA Fuel Rev 6 Canister Lid Assembly, Sealed Failed Fuel Can, TRIGA Fuel Rev 2 Canister Body Assembly, Sealed Failed Fuel Can, TRIGA Fuel Rev 4 Weldment, 7 Element Basket, 3 MTR Fuel Base Module Rev 4 Weldment, 7 Element Basket, 3 MTR Fuel Intermediate Module Rev 4 Weldment, 7 Element Basket, 3 MTR Fuel Top Module Rev 4 Legal Weight Truck Transport Cask Assembly, 3 MTR Element Rev 3 Fuel Cluster Rod Insert, TRIGA Fuel Sheets 1-3 Rev 6 PWR/BWR Rod Transport Canister Assembly Sheets 1-3 Rev 3 Can Weldment, PWR/BWR Transport Canister * Packaging Unit Nos. 1, 2, 3, 4 and are constructed in accordance with this revision of drawing. NAC International 1-iii

85 NAC-LWT Cask SAR February 2014 List of Drawings (continued) Sheets 1 - Rev 4 Lids, PWR/BWR Transport Canister Rev 0 4 X 4 Insert, PWR/BWR Transport Canister Rev 2 X Insert, PWR/BWR Transport Canister Rev 0 Pin Spacer, PWR/BWR Transport Canister Sheets 1-3 Rev Legal Weight Truck Transport Cask Assy, PWR/BWR Rod Transport Canister Sheets 1-2 Rev 3 PWR Insert PWR/BWR Transport Canister Sheets 1-3 Rev 1 MTR Plate Canister, LWT Cask Sheets 1-3 Rev 1 Weldment, 7 Cell Basket, Top Module, DIDO Fuel Sheets 1-3 Rev 1 Weldment, 7 Cell Basket, Intermediate Module, DIDO Fuel Sheets 1-3 Rev 1 Weldment, 7 Cell Basket, Base Module, DIDO Fuel Rev 2 Legal Weight Truck, Transport Cask Assy, DIDO Fuel Rev 0 Spacers, Top Module, DIDO Fuel Sheets 1-3 Rev 2 Top Module, General Atomics IFM, LWT Cask Sheets 1-2 Rev 1 Spacer, General Atomics IFM, LWT Cask Rev 1 Transport Cask Assembly, General Atomics IFM, LWT Cask Sheets 1-3 Rev 3 Transport Cask Assembly, Framatome/EPRI, LWT Cask Sheets 1-2 Rev 2 Weldments, Framatome/EPRI, LWT Cask Sheets 1-2 Rev 2 Spacer Assembly, TPBAR Shipment, LWT Cask Sheets 1-2 Rev 3 Legal Weight Truck, Transport Cask Assy, TPBAR Shipment Rev A RERTR Secondary Enclosure, General Atomics Rev A HTGR Secondary Enclosure, General Atomics Rev B RERTR Primary Enclosure, General Atomics Rev B HTGR Primary Enclosure, General Atomics Rev 1 Canister Body Assembly, Failed Fuel Can, PULSTAR Rev 1 Assembly, Failed Fuel Can, PULSTAR Sheets 1-2 Rev 1 Transport Cask Assembly, PULSTAR Shipment, LWT Cask Rev 1 Body Weldment, Screened Fuel Can, PULSTAR Fuel Rev 1 Assembly, Screened Fuel Can, PULSTAR Fuel Rev 1 Legal Weight Truck Transport Cask Assy, ANSTO Fuel Sheets 1-2 Rev 1 Weldment, 7 Cell Basket, Top Module, ANSTO Fuel Sheets 1-2 Rev 1 Weldment, 7 Cell Basket, Intermediate Module, ANSTO Fuel Sheets 1-2 Rev 1 Weldment, 7 Cell Basket, Base Module, ANSTO Fuel Rev 0 Irradiated Hardware Lid Spacer, LWT Cask Rev 0 Legal Weight Truck Transport Cask Assembly, ANSTO-DIDO Combination Basket Rev 2P LWT Transport Cask Assembly, HEUNL Contents Rev 0NP Rev 2P Container Assembly, HEUNL Rev 0NP Rev 1P Container Spacer, HEUNL1 Rev 0NP Rev 1P Container Guide, HEUNL Rev 0NP NAC International 1-iv

86 NAC-LWT Cask SAR April 2010 Revision 41 Table Terminology and Notation Cask Model Package Packaging NAC-LWT Cask NAC-LWT The Packaging with its radioactive contents (payload), as presented for transportation (10 CFR 71.4). Within this report, the Package is denoted as the NAC-LWT cask or simply as the cask. The assembly of components necessary to ensure compliance with packaging requirements (10 CFR 71.4). Within this report, the Packaging is denoted as the NAC-LWT cask. This packaging consists of a spent-fuel shipping cask body and closure lid with energy absorbing impact limiters. 1 Contents 1 PWR assembly (Payload) up to 2 BWR assemblies up to 2 PWR or BWR rods (including high burnup fuel rods and up to 14 fuel rods classified as damaged) 1 up to 16 PWR MOX fuel rods (or mixed contents of up to 16 PWR MOX and UO 2 PWR fuel rods) and up to 9 BPRs up to 42 MTR fuel elements (including plates) up to 42 DIDO fuel assemblies up to 7 degraded clad DIDO fuel assemblies in damaged fuel cans (DFCs) in ANSTO top basket module up to 1 sound (cladding intact) metallic fuel rods up to 9 damaged metallic fuel rods or 3 severely damaged metallic fuel rods in filters up to 140 intact or damaged TRIGA fuel elements/debris up to 60 intact or damaged TRIGA fuel cluster rods 2 GA IFM packages up to 300 TPBARs (including up to 2 prefailed TPBARs) up to TPBARs segmented into individual segments and segmentation debris up to 700 intact or damaged PULSTAR fuel elements in either assembly or element form, including fuel debris up to 42 intact spiral fuel assemblies (also referred to as Mark III spiral fuel), including up to 7 degraded clad spiral fuel assemblies in DFCs. Spiral fuel assemblies may be cropped. up to 42 intact MOATA plate bundles, including up to 7 MOATA plate bundles in DFCs PWR and BWR fuel rods may be transported in either a fuel assembly lattice (skeleton) or in a fuel rod insert. The fuel rod insert may contain PWR instrument/guide tubes and BWR water/inert rods in addition to the fuel rods. NAC International 1-3

87 NAC-LWT Cask SAR February 2014 Table Terminology and Notation (cont d) any combination of individual ANSTO basket modules containing either spiral fuel assemblies or MOATA plate bundles up to a total of 42 assemblies/bundles, including up to 7 degraded clad DIDO, spiral or MOATA elements/ bundles in DFCs placed in an ANSTO top basket module combination ANSTO-DIDO basket assembly (one ANSTO top module and five DIDO intermediate and base basket modules) containing up to 42 DIDO, spiral or MOATA elements/bundles with up to 7 degraded clad elements/bundles in the ANSTO top module in DFCs 4 HEUNL containers. Containers shall be either full or partially filled with HEUNL material, or empty. up to 4,000 lbs of solid, irradiated and contaminated hardware, which may include fissile material less than a Type A quantity and meeting the exemptions of 10 CFR 71.1, paragraphs (a), (b) and (c). Total allowed mass includes the weight of spacers, shoring and dunnage. Impact Limiters Intact LWR Fuel (Assembly or Rod) Damaged LWR Fuel (Assembly or Rod) Aluminum honeycomb energy absorbers located at the ends of the cask. Spent nuclear fuel that is not Damaged LWR Fuel, as defined herein. To be classified as intact, fuel must meet the criteria for both intact cladding and structural integrity. An intact fuel assembly can be handled using normal handling methods, and any missing fuel rods have been replaced by solid filler rods that displace a volume equal to, or greater than, that of the original fuel rod. Spent nuclear fuel that includes any of the following conditions that result in either compromise of cladding confinement integrity or recognition of fuel assembly geometry. 1. The fuel contains known or suspected cladding defects greater than a pinhole leak or a hairline crack that have the potential for release of significant amounts of fuel particles. 2. The fuel assembly: i. is damaged in such a manner as to impair its structural integrity; ii. has missing or displaced structural components such as grid spacers; NAC International 1-4

88 NAC-LWT Cask SAR April 2010 Revision Introduction The NAC-LWT spent-fuel shipping cask has been developed by NAC International (NAC) as a safe means of transporting radioactive materials authorized as approved contents. The cask design is optimized for legal weight over the road transport, with a gross weight of less than 80,000 pounds. The cask provides maximum safety during the loading, transport, and unloading operations required for spent-fuel shipment. The NAC-LWT cask assembly is composed of a package that provides a containment vessel that prevents the release of radioactive material. The actual containment boundary provided by the package consists of a 4.0-inch thick bottom plate, a 0.7-inch thick, inch inner diameter shell, an upper ring forging, and an 11.3-inch thick closure lid. The cask lid closure is accomplished using twelve, 1-inch diameter bolts. The cask has an outer shell, 1.20 inches thick, to protect the containment shell and also to enclose the.7-inch thick lead gamma shield. Neutron shielding is provided by a.0-inch thick neutron shield tank with a 0.24-inch (6mm) thick outer wall, containing a water/ethylene glycol mixture and 1.0 minimum weight percent (wt %) boron (8 wt % ethylene glycol; 39 wt % demineralized water; 3 wt % potassium tetraborate [K 2 B 4 O 7 ]). The neutron shield tank system includes an expansion tank to permit the expansion and contraction of the shield tank liquid without compromising the shielding or overstressing the shield tank structure. Aluminum honeycomb impact limiters are attached to each end of the cask to absorb kinetic energy developed during a cask drop, and limit the consequences of normal operations and hypothetical accident events. The NAC-LWT is a legal weight truck cask designed to transport the following contents: 1 PWR assembly; up to 2 BWR assemblies; up to 1 sound metallic fuel rods; up to 42 MTR fuel elements; up to 42 DIDO fuel assemblies; up to 2 high burnup PWR fuel rods (including up to 14 rods classified as damaged) 1 ; up to 2 high burnup BWR fuel rods (including up to 14 rods classified as damaged) 1 ; up to 16 PWR MOX fuel rods (or a combination of 16 PWR MOX and UO 2 PWR rods) and up to 9 BPRs up to 9 damaged metallic fuel rods; up to 3 severely damaged metallic fuel rods in filters; up to 140 TRIGA intact or damaged fuel elements/fuel debris ( TRIGA is a Trademark of General Atomics); up to 60 TRIGA intact or damaged fuel cluster rods/fuel debris; 2 GA IFM packages; up to 300 TPBARs (of which two can be prefailed) in a consolidation canister; PWR and BWR fuel rods may be transported in either a fuel assembly lattice (skeleton) or in a fuel rod insert. The fuel rod insert may contain PWR instrument/guide tubes and BWR water/inert rods in addition to the fuel rods. NAC International 1.1-1

89 "NAC PROPRIETARY INFORMATION" NAC-LWT Cask SAR REMOVED February 2014 up to 2 TPBARs (of which two can be prefailed) in a rod holder; up to TPBARs segmented during post-irradiation examination (PIE), including segmentation debris; up to 700 PULSTAR fuel elements (intact or damaged); up to 42 spiral fuel assemblies; up to 42 MOATA plate bundles; 4 HEUNL containers (to fill capacity, partially filled or empty); or up to 4,000 lbs of solid, irradiated and contaminated hardware, which may include fissile material less than a Type A quantity and meeting the exemptions of 10 CFR 71.1, paragraphs (a), (b) and (c). Total allowed mass includes the weight of spacers, shoring and dunnage. PWR or BWR fuel rods may be placed in a fuel rod insert (also referred to as a rod holder) or in a fuel assembly lattice. The fuel rod holder is composed of a 4 4 or a rod array. An alternate rod holder is designed to contain an oversize nonfuel-bearing component (e.g., CE guide tube or BWR water rod). The alternative configuration reduces fuel-bearing capacity to a maximum of 21 fuel rods. The lattice may be irradiated or unirradiated. Up to 14 of the fuel rods may be classified as damaged. Damaged fuel rods must be placed in a rod holder. Damaged fuel rods or rod sections may be encapsulated to facilitate handling prior to placement in the rod holder. PWR rods may include Integral Fuel Burnable Absorber (IFBA) rods. PWR MOX fuel rods (or a combination of PWR MOX and UO 2 PWR fuel rods) are required to be loaded in a screened or free flow PWR/BWR Rod Transport Canister with a insert. PWR MOX/UO 2 rods may include Integral Fuel Burnable Absorber (IFBA) rods. Damaged TRIGA fuel elements, cluster rods and fuel debris are required to be loaded in a sealed damaged fuel canister (DFC). PULSTAR fuel elements may be configured as intact fuel assemblies, may be placed into a fuel rod insert, i.e., a 4 4 rod holder (intact elements only), or may be loaded into one of two can designs, designated as the PULSTAR screened fuel can or the PULSTAR failed fuel can. Damaged PULSTAR fuel elements and nonfuel components of PULSTAR fuel assemblies must be loaded into cans. PULSTAR fuel cans may only be loaded into the top or base module of the 28 MTR basket assembly. Intact PULSTAR fuel assemblies and intact PULSTAR fuel elements in a TRIGA fuel rod insert may be loaded in any basket module. Four HEUNL containers may be loaded directly into the NAC-LWT cask cavity. Each container may be filled to the point when material reaches the vent port during fill operations. Partially filled containers are permitted for transport. NAC International 1.1-2

90 NAC-LWT Cask SAR December 2012 Revision LWT-12E seals. For all other contents, the leaktight capable (i.e., no credible leakage) alternate port covers incorporating Viton O-ring seals can be used. The transport arrangement drawings for approved contents are presented in Section 1.4. An alternative drain tube, including a drain tube alignment ring, is required to be installed and utilized when loading and transporting modular fuel baskets (i.e., not full length) and canisters. The impact limiters and the personnel barrier are designed to be removed and installed without the aid of supplemental lifting gear or fixtures. All approved content may be transported in an International Shipping Organization (ISO) container, except for PWR and BWR fuel assemblies. All operational features are readily apparent from the drawings provided in Section 1.4. Operational procedures are delineated in Chapter Contents of Packaging The NAC-LWT cask is analyzed, as presented in this SAR, for the transport of the contents listed in Table and Section 1.1. Shipments in the NAC-LWT package shall not exceed the following limits: 1. The maximum contents weight shall not exceed 4,000 pounds. 2. The limits specified in Table through Table for the fuel and other radioactive contents shall not be exceeded. 3. Any number of casks may be shipped at one time, one cask per tractor/trailer vehicle. 4. The maximum decay heat shall not exceed the following: 2. kw for PWR fuel assemblies; 2.2 kw for BWR fuel assemblies; 2.3 kw for 2 high burnup PWR fuel rods; 2.1 kw for 2 high burnup BWR fuel rods; 2.3 kw for 16 PWR MOX/UO 2 fuel rods; 1.26 kw for MTR fuel; 1.0 kw for DIDO fuel assemblies with top spacer and 0.76 kw without top spacer; 1.0 kw for TRIGA fuel elements or fuel cluster rods; 13.0 W for GA IFM packages; kw for 300 TPBARs; kw for TPBAR segments; 0.08 kw for 2 TPBARs; 0.84 kw for the PULSTAR fuel contents; 0.69 kw for spiral fuel assemblies (0.109 kw per basket); kw for MOATA plate bundles (21 W per basket); W for HEUNL; and 1.26 kw for solid, nonfissile, irradiated hardware.. Radiation levels shall meet the requirements delineated in 10 CFR or 49 CFR The neutron shield tank may be drained for shipment of metallic fuel rods. 6. Surface contamination levels shall meet the requirements of 10 CFR 71.87(i) or 49 CFR Damaged TRIGA fuel elements and fuel debris (up to two equivalent elements) will be shipped in a sealed damaged fuel canister. 8. Damaged TRIGA cluster rod and fuel debris will be transported in a sealed damaged fuel canister (maximum of up to six equivalent fuel cluster rods). 9. MTR fuel elements may consist of any combination of intact or damaged highly enriched uranium (HEU), medium enriched uranium (MEU) or low enriched uranium (LEU) fuel elements that are enveloped by the parameters listed in Table as supported by NAC International 1.2-

91 NAC-LWT Cask SAR February 2014 information presented in Table.1.1-2, Table , Table , Table and Table MTR fuel elements will be transported in a leaktight configuration NAC-LWT cask. 10. High burnup PWR fuel rods will be shipped in either a sealed, free flow or screened can. 11. High burnup BWR fuel rods will be shipped in either a sealed, free flow or screened can. 12. Up to 2 high burnup PWR or BWR fuel rods in a fuel assembly lattice or rod holder. Up to 14 of the fuel rods in a rod holder may be classified as damaged. Damaged fuel rods or rod sections may be placed into fuel rod capsules prior to placing them in the fuel rod holder. Typical failed fuel rod capsule configuration is shown in Figure Production TPBARs will either be shipped in an open top consolidation canister as shown in Figure and assembled in the cask as shown in Figure , or shipped in a PWR/BWR Rod Transport Canister in accordance with License Drawing No Intact PULSTAR fuel elements may be loaded into a fuel rod insert or the PULSTAR screened or failed fuel can. 1. Damaged PULSTAR fuel elements and nonfuel components of PULSTAR fuel assemblies shall be loaded into either a PULSTAR failed fuel or screened fuel can, and placed into the top or base module of the 28 MTR fuel basket. Damaged fuel, including fuel debris, may be placed in an encapsulating rod prior to loading in a PULSTAR can. 16. Any combination of spiral fuel assemblies or MOATA plate bundles, each loaded into separate ANSTO basket modules containing up to a total of 42 assemblies/bundles. 17. Segmented TPBARs will be shipped in a sealed, dry Waste Container as shown in Figure and assembled in the cask as shown in Figure Solid, irradiated and contaminated hardware containing less than a Type A quantity of fissile material and meeting the exemptions of 10 CFR 71.1, paragraphs (a), (b) and (c), loaded directly into the cask or contained in a secondary container or basket. The irradiated hardware spacer will be installed to limit the axial movement of the hardware above the lead shielded region of the cask body. As needed, additional secondary containers, dunnage and shoring may be used to limit the movement of the contents during normal and accident conditions of transport. 19. PWR MOX fuel rods (or a combination of PWR MOX and UO 2 PWR fuel rods) are required to be loaded in a screened or free flow PWR/BWR Rod Transport Canister provided with a insert. 20. Any combination of up to 7 degraded clad DIDO, spiral or MOATA plate elements/ bundles loaded into an aluminum screened DFC as shown Figure placed in an ANSTO top basket module, with remainder of either ANSTO basket modules containing MOATA plate bundles or spiral fuel elements or ANSTO-DIDO combination basket containing DIDO elements. Degraded aluminum-clad DIDO, spiral or MOATA plate elements/bundles will be transported in a leaktight configuration NAC-LWT cask. 21. Four HEUNL containers. Containers shall be either full or partially filled with HEUNL material or empty. NAC International 1.2-6

92 NAC-LWT Cask SAR April 2010 Revision 41 plates. Two thick (0.63 cm) aluminum nonfuel side plates support the fuel plate stack from two sides, making a possible total of 16 plates per bundle. At each axial end, the plates in the stack are connected by a pin. Spacing between plates is maintained by disk spacers placed onto the top and bottom pins between each fuel plate and the aluminum side plates. A sketch of a typical MOATA plate bundle is provided in Figure Solid, Irradiated and Contaminated Hardware The design basis characteristics of the solid, irradiated and contaminated hardware are provided in Table As described in the content definition, the solid, irradiated and contaminated hardware may contain small quantities of fissile materials. Fissile materials in the irradiated hardware contents are acceptable if the quantity of fissile material does not exceed a Type A quantity and does not exceed the exemptions of 10 CFR 71.1, paragraphs (a), (b) and (c). The irradiated hardware may be directly loaded into the NAC-LWT cask cavity, or may be contained in a secondary container or basket. As needed, appropriate component spacers, dunnage and shoring may be used to limit the movement of the contents during normal and accident conditions of transport. To ensure that the movement of the irradiated hardware contents above the lead shielded length of the NAC-LWT cask body (i.e., the approximately upper 6.2 inches of the cavity length) is precluded, an Irradiated Hardware Lid Spacer as shown on Drawing No shall be installed for all irradiated hardware content configurations. The total installed height of the spacer is 6. inches. Therefore, the available cavity length for the irradiated hardware is approximately 171 inches. The NAC-LWT cask shall be assembled for transport as shown on NAC Drawing No with the irradiated hardware spacer installed on the lid. A comparative shielding evaluation for a conservatively selected irradiated hardware transport configuration (i.e., a single line source with no self-shielding) or consideration of the additional shielding provided by additional spacers, dunnage, inserts or secondary containers is presented in Chapter. The evaluations show that the regulatory dose rate requirements per 10 CFR for normal conditions of transport, or 10 CFR 71.1(b) under hypothetical accident conditions, are not exceeded PWR MOX Fuel Rods The NAC-LWT cask is analyzed and evaluated for the transport of up to 16 PWR MOX fuel rods (or a combination of up to 16 PWR MOX and UO 2 fuel rods) loaded into a insert placed in a screened or free flow PWR/BWR Rod Transport Canister. The authorized characteristics of NAC International

93 "NAC PROPRIETARY INFORMATION" NAC-LWT Cask SAR REMOVED February 2014 the evaluated PWR MOX fuel rods are provided in Table For mixed PWR MOX and UO 2 PWR fuel rod combinations, the UO 2 PWR fuel rods may have the identical heat load, burnup and cool time characteristics as the PWR MOX fuel rods. In addition to the 16 PWR MOX fuel rods (or a combination of PWR MOX and UO 2 PWR fuel rods), up to 9 burnable poison rods (BPRs) may be loaded in the remaining openings in the insert in the PWR/BWR Rod Transport Canister HEUNL Containers HEUNL material packaged in HEUNL containers may be directly loaded into the NAC-LWT cavity. Four containers must be packaged in the NAC-LWT for transport. The containers may be partially filled. A sketch of the HEUNL container is provided in Figure The container design is presented in NAC drawing HEUNL material consists of a solution of uranyl nitrate, various other nitrates (primarily aluminum nitrate), and water. The solution may contain uranyl nitrates with up to 7.40 g/l 23 U. Key physical, radiation protection, and thermal characteristics of the HEUNL material are provided in Table NAC International

94 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure HEUNL Container NAC International

95 NAC-LWT Cask SAR December 2012 Revision LWT-12E Table Characteristics of Design Basis TRIGA Fuel Elements Acceptable for Loading in the Poisoned TRIGA Basket TRIGA HEU (Notes 1, 2, 6 & 7) TRIGA LEU (Notes 1, 2, 6 & 7) TRIGA LEU (Notes 1, 2, 6 & 7) Fuel Form Clad U-ZrH rod Clad U-ZrH rod Clad U-ZrH rod Maximum Element Weight, lbs Maximum Element Length, in Element Cladding Stainless Steel Stainless Steel Aluminum Clad Thickness, in Active Fuel Length, in (Note 4) Element Diameter, in max max max. Fuel Diameter, in 1.43 max max max. Maximum Initial U Content/Element, kilograms Maximum Initial 23 U Mass, grams Maximum Initial 23 U Enrichment, weight percent Zirconium Mass, grams (Note ) Hydrogen to Zirconium Ratio, max. (Note ) Maximum Average Burnup, 460,000 11,100 11,100 Notes: MWd/MTU Minimum Cooling Time (80% 23 U) 90 days (Note 3) (80% 23 U) 90 days (Note 3) (80% 23 U) 90 days (Note 3) 1. Mixed TRIGA LEU and HEU contents authorized. 2. TRIGA Standard, instrumented and fuel follower control rod type elements authorized. 3. Maximum decay heat of any element is 7. watts. 4. Aluminum clad fuel with 14-inch active fuel is solid and has no central hole with a zirconium rod.. Zirconium mass and H/Zr ratio apply to the fuel material (U-Zr-H x ) and do not include the center zirconium rod. 6. Listed TRIGA fuel elements have a 0.22-inch diameter zirconium rod in the center. 7. Dimensions listed are as-fabricated (unirradiated) nominal values. NAC International

96 NAC-LWT Cask SAR February 2014 Table HEUNL Characteristics Parameter Maximum HEUNL payload per Container Maximum Cask Heat Load Maximum Per Container Heat Load Maximum HEUNL Heat Load Maximum Curie Content (gamma emitters) 1 Maximum 23 U content 2 Maximum 23 U enrichment 2 Value 64.3 L (17.0 gal) W 3.22 W 0.02 W/L 9.0 Ci/L 7.4 g 23 U/L 93.4 wt% 1 Maximum Curie content defined by source term and shielding evaluations. 2 Maximum 23 U content and enrichment defined by criticality evaluation. NAC International 1.2-3

97

98 NAC-LWT Cask SAR February 2014 Table of Contents (continued) ANSTO Basket Analysis TPBAR Basket with the PWR/BWR Rod Transport Canister HEUNL Container Conclusion Hypothetical Accident Conditions Free Drop (30 Feet) End Drop Side Drop Oblique Drops Shielding for Lead Slump Accident Bolts - Closure Lid (Hypothetical Accident - Free Drop) Crush Rod Shipment Can Assembly Analysis Puncture Puncture - Cask Side Midpoint Puncture - Center of Cask Closure Lid Puncture - Center of Cask Bottom Puncture - Port Cover Puncture Accident - Shielding Consequences Puncture - Conclusion Fire Discussion Thermal Stress Evaluation Bolts - Closure Lid (Hypothetical Accident - Fire) Inner Shell Evaluation Conclusion Immersion - Fissile Material Immersion Irradiated Nuclear Fuel Packages Method of Analysis Closure Lid Stresses Outer Bottom Head Forging Stresses Cask Cylindrical Shell Stresses Containment Seal Evaluation Damage Summary Fuel Basket / Container Accident Analysis Discussion PWR Basket Construction PWR Basket Analysis BWR Basket Construction Metallic Fuel Basket Analysis MTR Fuel Basket Construction Conclusion PWR Spacer NAC International 2-iii

99 NAC-LWT Cask SAR December 2012 Revision LWT-12E Table of Contents (continued) TRIGA Fuel Basket Thirty-Foot Drop Evaluation DIDO Fuel Basket Construction General Atomics IFM Basket Construction TPBAR Basket Analysis ANSTO Basket Analysis TPBAR Basket with the PWR/BWR Rod Transport Canister HEUNL Container Special Form Spent Fuel Contents PWR and BWR Fuel Rods TRIGA Fuel Elements End Drop Side Drop PULSTAR Intact Fuel Elements ANSTO Fuels MARK III Spiral Fuel Assemblies MOATA Plate Bundles DIDO Fuel Assemblies Appendices Computer Program Descriptions ANSYS RBCUBED - A Program to Calculate Impact Limiter Dynamics Finite Element Model Description Boundary and Loading Conditions Used in the 30-Foot Drop Finite Element Analysis Finite Element Evaluations Isothermal Plot - Hot Case Isothermal Plot - Cold Case Determination of Component Critical Stresses Oblique Drop Slapdown Discussion Analysis Energy Calculation Rotational Velocity Change Lead Slump - End Drop Inner Shell Buckling Design Criteria and Evaluation Code Case N Theoretical Elastic Buckling Stresses Capacity Reduction Factors Plasticity Reduction Factors Upper Bound Magnitudes for Compressive Stresses and In-Plane Shear Stresses Interaction Equations NAC International 2-iv

100 NAC-LWT Cask SAR April 2010 Revision 41 List of Figures Figure Design Fatigue Curve for High Strength Steel Bolting Figure Static Stress-Strain Curve for Chemical Copper Lead Figure Dynamic Deformation Stress-Strain Curve for Chemical Copper Lead Figure Trunnion Cross-Section and Forging Shear Area Figure Front Support and Tiedown Geometry Figure Pressure Distribution of Horizontal Bearing Between Cask and Support Saddle Figure Free Body Diagram of Cask Subjected to Lateral Load Figure Rotation Trunnion Pocket Figure NAC-LWT Cask Critical Sections (Hot Case) Figure NAC-LWT Cask Critical Sections (Cold Case) Figure Foot Bottom End Drop with 130 F Ambient Temperature and Maximum Decay Heat Load Figure Foot Bottom End Drop with -40 F Ambient Temperature and Maximum Decay Heat Load Figure Foot Bottom End Drop with -40 F Ambient Temperature and No Decay Heat Load Figure Foot Top End Drop with 130 F Ambient Temperature and Maximum Decay Heat Load Figure Foot Top End Drop with -40 F Ambient Temperature and Maximum Decay Heat Load Figure NAC-LWT Cask Critical Sections (1-Foot Side Drop with 100 F Ambient Temperature) Figure Foot Top Corner Drop with 130 F Ambient Temperature and Maximum Decay Heat Load - Drop Orientation = 1.74 Degrees Figure Foot Bottom Corner Drop with 130 F Ambient Temperature and Figure Maximum Decay Heat Load - Drop Orientation = 1.74 Degrees Foot Top Corner Drop with -40 F Ambient Temperature and No Decay Heat Load - Drop Orientation = 1.74 Degrees Figure NAC-LWT Cask with Impact Limiters Figure Cross-Section of Top Impact Limiter Figure Load Versus Deflection Curve (Typical Aluminum Honeycomb) Figure Quarter-Scale Model Limiter End Drop Cross-Section Figure End Drop Impact Limiter Cross-Section Figure Impact Limiter Lug Detail Figure Cask Lug Detail Figure RBCUBED Output Summary Center of Gravity Over Top Corner Figure Free Body Diagram - Top Impact Limiter - Center of Gravity Over Corner Figure Free Body Diagram - Top Impact Limiter - Cask Wedging Forces Figure Cask Lid Configuration Figure Closure Lid Free Body Diagram NAC International 2-vii

101 NAC-LWT Cask SAR February 2014 List of Figures (continued) Figure NAC-LWT Cask Cross-Section Figure Component Parts of Shield Tank Structure Figure Shield Tank Cross-Section Figure Shield Tank Quarter-Section Geometry Figure Partial Bottom/Top End Plate Plan and Cross-Section Figure Shield Tank End Plate Figure Gusset Profile Figure End Plate Welds Figure Component Parts of the Expansion Tank Structure Figure Expansion Tank Top and Bottom End Plate Figure Expansion Tank Stiffener Load Geometry Figure Cask Upper Ring at Trunnion - ANSYS Model Figure Cask Upper Ring at Trunnion - Model Loads and Boundary Conditions Figure NACAC-LWT Cask Upper Ring at Trunnion - Critical Sections Figure Impact of Penetration Cylinder on Neutron Shield Tank and Figure Expansion Tank Points of Impact Impact of Penetration Cylinder on Neutron Shield Tank and Expansion Tank Details for Analysis Figure Impact of Penetration Cylinder on Port Cover Figure One-Sixth Model of the Alternate Port Cover 60 Symmetry Figure Cask Side Drop Fuel Tube Loading MTR Fuel Basket Figure Baseplate Supports for Cask End Drop Loads - MTR Fuel Basket Figure DIDO Fuel Basket Module Structural Model Top View Figure DIDO Fuel Basket Module Structural Model Bottom View Figure Figure DIDO Fuel Basket Module Maximum Stress Locations for the Side Drop Orientation DIDO Fuel Basket Module Maximum Stress Locations for the End Drop Orientation Figure Cross-Section of TPBAR Basket Figure TPBAR Spacer Schematic Triangular Top Plate and Tube Figure HEUNL Container Outside View Figure HEUNL Container Inside View Figure HEUNL Container Gap Elements Shown Figure HEUNL Container Support Ring Sector Model Figure Closure Assembly Model Figure Bolt Modeling Figure Fill/Drain Port Model Figure HEUNL Container Section Locations Figure HEUNL Container Section Locations Figure Stress Linearization Paths in Closure Lid Figure Stress Linearization Paths in Fill/Drain Ports NAC International 2-viii

102 NAC-LWT Cask SAR February 2014 List of Figures (continued) Figure Foot Bottom End Drop with 130 F Ambient Temperature and Maximum Decay Heat Load Figure Foot Bottom End Drop with -40 F Ambient Temperature and Maximum Decay Heat Load Figure Foot Bottom End Drop with -40 F Ambient Temperature and No Decay Heat Load Figure Foot Top End Drop with 130 F Ambient Temperature and Maximum Decay Heat Load Figure Foot Top End Drop with -40 F Ambient Temperature and Maximum Decay Heat Load Figure Circumferential Load Distribution for Cask Side Drop Impact Figure Six Term Fourier Series Representation of Circumferential Load Distribution for Cask Side Drop Impact Figure NAC-LWT Cask Critical Sections (30-Foot Side Drop with 100 F Ambient Temperature) Figure Circumferential Load Distribution for Cask Oblique Drop Impact Figure Foot Top Corner Drop with 130 F Ambient Temperature - Drop Orientation = 1.74 Degrees Figure Foot Top Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 30 Degrees Figure Foot Top Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 4 Degrees Figure Figure Foot Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 60 Degrees Foot Top Corner Drop with -40 F Ambient Temperature - Drop Orientation = 1.74 Degrees Figure Foot Top Oblique Drop with -40 F Ambient Temperature - Drop Orientation = 30 Degrees Figure Foot Top Oblique Drop with -40 F Ambient Temperature - Drop Orientation = 4 Degrees Figure Foot Top Oblique Drop with -40 F Ambient Temperature - Drop Orientation = 60 Degrees Figure Foot Bottom Oblique Drop with 130 F Ambient Temperature Drop Orientation = 1.74 Degrees Figure Foot Bottom Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 30 Degrees Figure Foot Bottom Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 4 Degrees Figure Foot Bottom Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 60 Degrees Figure Sectional Stress Plot - 30-Foot Bottom Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 60 Degrees NAC International 2-ix

103 NAC-LWT Cask SAR February 2014 List of Figures (continued) Figure Sectional Stress Plot (P m ) 30-Foot Bottom Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 60 Degrees Figure Sectional Stress Plot (P m + P b ) - 30-Foot Bottom Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 60 Degrees Figure Bottom Closure Plate - Section Cut Identification Figure Sectional Stress Plot - 30-Foot Bottom Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 4 Degrees Figure Sectional Stress Plot - 30-Foot Bottom Oblique Drop with 130 F Ambient Temperature - Drop Orientation = 30 Degrees Figure NAC-LWT Cask Midpoint Section Figure Cask Lid Configuration Figure NAC-LWT Cask Bottom Design Configuration Figure Port Cover Geometry Figure Puncture of Cask at Valve Cover Region Figure Alternate Port Cover Thermal Analysis Geometry Figure PWR Spacer Geometry Figure Internal Pressure Case 30 Sector Model Figure DIDO Fuel Assembly Model and Boundary Conditions Figure DIDO Stress Intensities for 30-Foot Side Drop Figure ANSYS Finite Element Model NAC-LWT Cask Figure Cask Bottom of Model Figure Inner, Lead and Outer Shells Lower Region of Model Figure Inner, Lead and Outer Shells Lower Middle Region of Model Figure Inner, Lead and Outer Shell Upper Middle Region of Model Figure Inner, Lead and Outer Shells Upper Region of Model Figure Upper Ring Forging on Model Figure Closure Lid on Model Figure ANSYS Finite Element Model Component Identification Figure NAC-LWT Cask Isotherms (Hot Case) Figure NAC-LWT Cask Isotherms (Cold Case) Figure Stress Contour Plot Hot Case Figure Cask Slapdown Geometry Figure Force Deflection Curve of Drop Tested Limiter 0-Degree Impact Figure Force Deflection Curve of Drop Tested Limiter 14-Degree Impact Figure Force Deflection Curve of Drop Tested Limiter 90 Degree Impact Figure Oblique Drop Figure Representative Section Cut Diagram Figure Drawing of Quarter-Scale Model Figure Drawing of Model Body Figure Drawing of Model Lid Figure Drawing of Model Upper Impact Limiter Figure Drawing of Model Lower Impact Limiter Figure Drawing of Model Simulated Cask Contents NAC International 2-x

104 NAC-LWT Cask SAR February 2014 List of Figures (continued) Figure Quarter-Scale Model Figure Model Rigged for 30-Foot End Drop Figure Model Positioned for 30-Foot End Drop Figure Model Position Following 30-Foot End Drop Figure Top End Impact Limiter Following 30-Foot End Drop Figure Exterior of Top Impact Limiter Following 30-Foot End Drop Figure Model Rigged for 30-Foot Corner Drop Figure Model Positioned for 30-Foot Corner Drop Figure Model Following 30-Foot Corner Drop Figure Top Impact Limiter Following 30-Foot Corner Drop Figure Model Position Following 30-Foot Side Drop View Figure Model Position Following 30-Foot Side Drop View Figure Top Impact Limiter Following 30-Foot Side Drop Figure Bottom Impact Limiter Following 30-Foot Side Drop View Figure Bottom Impact Limiter Following 30-Foot Side Drop View Figure Model Rigged for 30-Foot Oblique Drop Figure Model Positioned for 30-Foot Oblique Drop Figure Model Position Following 30-Foot Oblique Drop Figure Bottom Impact Limiter Following 30-Foot Oblique Drop Figure Top Impact Limiter Following 30-Foot Oblique Drop Figure Model Rigged for Midpoint 40-Inch Pin Drop Figure Model Positioned for 40-Inch Pin Drop Figure Instant Before Midpoint 40-Inch Pin Drop Figure Model Position Following Midpoint 40-Inch Pin Drop Figure Impact Location Midpoint 40-Inch Pin Drop Figure Angular Orientation of Instrumentation Figure Strain Gauge Time History for Channel 3 End Drop Figure Strain Gauge Time History for Channel 4 End Drop Figure Strain Gauge Time History for Channel End Drop Figure Strain Gauge Time History for Channel 3 Side Drop Figure Strain Gauge Time History for Channel 4 Side Drop Figure Strain Gauge Time History for Channel Side Drop Figure Location of Block Sets Figure Stress Point Locations Figure Mathmatical Model of NAC-LWT Cask (30-foot Top End Impact Figure Side Drop ( = 90 ) Figure End Drop (0 < 1 ) Figure Oblique Drop (1 < 90 ) Figure Force Deflection Graph (0-Degree, Top End Drop) Figure Force-Deflection Graph (0-Degree, Bottom-End Drop) Figure Force-Deflection Graph (1.74-Degree, Top Corner Drop) Figure Force-Deflection Graph (14.-Degree, Bottom Corner Drop) Figure Force-Deflection Graph (30-Degree, Top Oblique Drop) NAC International 2-xi

105 NAC-LWT Cask SAR February 2014 List of Figures (continued) Figure Force-Deflection Graph (30-Degree, Bottom Oblique Drop) Figure Force-Deflection Graph (4-Degree, Top Oblique Drop) Figure Force-Deflection Graph (4-Degree, Bottom Oblique Drop) Figure Force-Deflection Graph (60-Degree, Top Oblique Drop) Figure Force-Deflection Graph (60-Degree, Bottom Oblique Drop) Figure Force-Deflection Graph (7-Degree, Top Oblique Drop) Figure Force-Deflection Graph (7-Degree, Bottom Oblique Drop) Figure Force-Deflection Graph (90-Degree, Top Side Drop) Figure Force-Deflection Graph (90-Degree, Bottom Side Drop) Figure Force-Deflection Curve (0-Degree Impact, Drop Tested Limiter) Figure Force-Deflection Curve (14-Degree Impact, Drop Tested Limiter) Figure Force-Deflection Curve (90-Degree Impact, Drop Tested Limiter) Figure End Drop Impact Limiter Cross Section Figure LWT Cask, Metal Fuel Basket Assembly Safety Analysis Report, NAC Drawing No Figure Liner-Failed Fuel Can, 2.7 I.D., LWT Cask, Safety Analysis Report, NAC Drawing No Figure Failed Fuel Rod Can 4.00 I.D., Fuel Rod Containerization, NAC Drawing No D Figure Failed Fuel Rod Can 2.7 I.D., Fuel Rod Containerization, NAC Drawing No D Figure Failed Fuel Filter, NAC Drawing No Figure ANSYS Finite Element Model of the Cask Body Figure Detailed View of the Cask Body Finite Element Model Top Figure Detailed View of the Cask Body Finite Element Model Bottom Figure Location of Sections of the NAC-LWT Cask Body Model Figure Alternate B Port Cover Finite Element Model NAC International 2-xii

106 NAC-LWT Cask SAR April 2010 Revision Weights and Centers of Gravity Major Component Statistics The weights of the major components of the NAC-LWT cask and their respective centers of gravity are presented in Table The axial location of the center of gravity is measured from the bottom surface of the cask body. The center of gravity is always on the longitudinal centerline of the cask because the cask is essentially axisymmetric about that axis. The center of gravity location of the fuel is representative of typical fuel configurations. The weights and centers of gravity of the cask package in eight different shipping configurations are presented in Table In each case, the center of gravity is measured from the bottom surface of the cask body. The term loaded refers to the presence of fuel or other radioactive materials in the cask cavity; the term empty implies the absence of any fuel or other radioactive materials in the cask cavity. However, the fuel basket does remain in the cask cavity for the empty configuration. The weight of a lifting yoke is not included in the tabulated package weights. All of the values tabulated in Table and Table are calculated to the nearest pound to obtain an accurate cask weight and center of gravity. The cask package weight and center of gravity used in the analyses of this report are the design values - 2,000 pounds and inches. A design value of 4,000 pounds is conservatively used for the total weight of the cask contents (including the appropriate basket). NAC International

107 NAC-LWT Cask SAR February 2014 Table Weights of the NAC-LWT Cask Major Components Component Weight (pounds) Axial Center of Gravity Location (inches) Cask Body 39, Closure Lid and Bolts Impact Limiters Top Bottom 1,3 1, Shield Tank Fluid 3, PWR Fuel Basket and Spacer PWR High Burnup Rod Payload 1, PWR Fuel Payload (Maximum) 3, BWR Fuel Basket 1, BWR Fuel Payload 1, Metallic Fuel Basket Metallic Fuel Payload 2, MTR Four Unit Basket MTR Four Unit Fuel Payload MTR Four Unit PULSTAR Fuel Payload 2, MTR Five Unit Basket 1, MTR Five Unit Fuel Payload 1, MTR Six Unit Basket 1, MTR Six Unit Fuel Payload 1, GA IFM Basket and Spacer GA IFM Fuel Payload TPBAR Basket and Spacer TPBAR Payload ANSTO Basket ANSTO Payload TPBAR Basket TPBAR with Rod Transport Canister Payload 1, HEUNL Container & Spacer 1, HEUNL Payload For conservatism, a design basis MTR fuel weight of 30 lbs/assy is used in the structural analysis. The maximum MTR element weight is 13.2 lbs for an intact element and 9.7 lbs for the cut elements in the 42-element configuration. 2 For conservatism, a bounding weight of 80 pounds is considered for each of the 28 fuel cells for PULSTAR fuel 3 TPBAR payload represents the combined weight of the TPBAR and consolidation canister. A conservative 1,000 lb weight is applied in the structural analysis. 4 TPBAR with Rod Transport Canister payload represents the combined weight of the 2 TPBARs, the PWR /BWR Rod Transport Canister and the PWR insert. Includes 4 HEUNL Containers, Container Guide and Container Spacer. NAC International

108 NAC-LWT Cask SAR April 2010 Revision 41 Table Weights and Center of Gravity Locations for the NAC-LWT Cask Shipping Configurations Component Weight (pounds) Axial Center of Gravity Location (inches) Package -Loaded for Shipment (PWR) 1, Maximum Payload Package Loaded for Shipment PWR High 49, Burnup Rods Package - Empty for Shipment (PWR) 48, Package - Loaded for Shipment (BWR) 49, Package - Empty for Shipment (BWR) 48, Package - Loaded for Shipment* 4, (Metallic Fuel) Package - Empty for Shipment* 43, (Metallic Fuel) Package - Loaded for Shipment (PULSTAR 0, Fuel, MTR Four Unit Basket) Package - Loaded for Shipment 49, (MTR Fuel, Four Unit Basket) Package - Empty for Shipment 48, (MTR Fuel, Four Unit Basket) Package - Loaded for Shipment 49, (MTR Fuel, Five Unit Basket) Package - Empty for Shipment 48, (MTR Fuel, Five Unit Basket) Package - Loaded for Shipment 49, (MTR Fuel, Six Unit Basket) Package - Empty for Shipment 48, (MTR Fuel, Six Unit Basket) Package - Loaded for Shipment 48, (GA IFM Fuel and Basket) Package - Empty for Shipment 48, (GA IFM Basket) Package Loaded for Shipment 48, (TPBARs and Basket) Package Empty for Shipment 47, (TPBAR Basket) Package - Loaded for Shipment 48, (ANSTO Fuel and Basket) Package - Empty for Shipment (ANSTO Basket) 48, * Neutron Shield Tank is empty. NAC International

109 NAC-LWT Cask SAR February 2014 Table Weights and Center of Gravity Locations for the NAC-LWT Cask Shipping Configurations (cont d) Component Weight (pounds) Axial Center of Gravity Location (inches) Package Loaded for Shipment 49, TPBARs in the PWR/BWR Rod Transport Canister Package Empty for Shipment 47, (TPBAR Basket for PWR/BWR Rod Transport Canister) Package Empty for Shipment 48, (HEUNL) Package Loaded for Shipment 49, (HEUNL) Package Design for Shipment 2, NAC International

110 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Transport Canister (66 lbs). Therefore, no further analysis is required for the 4 4 and inserts HEUNL Container There will be a total of 4 HEUNL containers in the LWT cask. A support spacer will be located at the bottom of the LWT cask between the bottom container and the bottom forging of the LWT cask. The HEUNL containers and the support ring are structurally evaluated with a combination of standard handbook formulas and finite element models. The weight of each container is 320 lbs and the weight of the HEUNL fluid was calculated to be 17 lbs which gives a total of 49 lbs. For the structural analysis the fluid weight was conservatively assumed to be 180 lbs. This gives a total weight of 00 lbs total. A partially filled container would weigh less but it is conservative to use the weight of a fully filled container Finite Element Models HEUNL Container FEA Model The finite element model (FEA) was constructed of ANSYS SOLID4 3D elements and CONTAC2 gap elements. Both the HEUNL container and contained fluid were modeled. There NAC International

111 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 are CONTAC2 elements between the outside surface of the fluid region and the inner surface of the container to model the compression only loading by the liquid. For the side drop case, CONTAC2 elements were added to the outer surface of the guide rails to determine the load distribution between the HEUNL container and the inner surface of the LWT cask. The HEUNL container FEA model is shown in the Figure through Figure Figure HEUNL Container Outside View Figure HEUNL Container Inside View NAC International

112 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2013 Revision LWT-13B Figure HEUNL Container Gap Elements Shown Support Ring Model The support ring is a flat annular, machined ring. The support ring is constructed from SA-240, Type 304. An axisymmetric FEA model of the support ring was constructed for the bottom drop structural evaluation. Gap elements were placed at the bottom edge of the ring to account for possible lift-off of one edge. The support ring is not loaded significantly by the side drop or the top end drop. The FEA Model is shown in Figure Vertical constraints were applied to the lower end of the gap elements and a pressure load was applied to the model top surface for the inertial load of the containers. NAC International

113 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure HEUNL Container Support Ring Sector Model Closure Assembly Model The closure lid is a circular flat plate which is attached to the container head with six ½ inch-13 UNC cap screws. There are two O-rings under the closure lid for sealing purposes. A quarter symmetry model is used for the closure assembly. The closure lid, the O-rings, a portion of the container head and the liquid region are modeled with ANSYS SOLID4, 3D solid elements. The bolts are modeled with ANSYS BEAM4, 3D beam elements. The beam elements representing the bolts are connected to the 3D solid elements with a spider array of rigid, massless beam elements. The FEA model is shown in Figure and Figure Closure Assembly Model NAC International

114 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure Bolt Modeling Fill/Drain Port FEA Model The fill/drain port model is shown in Figure The geometry was imported into the ANSYS software from AutoCAD and meshed with SOLID186, 3D solid elements. Due to the complexity of the geometry, tetrahedral elements are used. This is an acceptable approach since the elements have mid-side nodes. Note that the fluid region is included in the model for evaluation of freezing of the HEUNL fluid due to cold conditions. In the model, the fluid region extends up to the bottom edge of the counter-bore which neglects the presence of the quick disconnect. This is a conservative approach since it produces more expansion in this region. Also note that a mesh sensitivity study was conducted to arrive at the mesh density shown below. Figure Fill/Drain Port Model NAC International

115 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February HEUNL Container 1-Foot Drop Cases and Pressure Cases The HEUNL container is evaluated for both end drops (top and bottom drops) and a side drop. An equivalent acceleration of 2 g is used to evaluate the 1-foot drops. For each drop case the FEA model is utilized. The linearized stresses are checked at 14 section locations. These sections used are shown in Figure and Figure Figure HEUNL Container Section Locations Figure HEUNL Container Section Locations NAC International

116 NAC-LWT Cask SAR February 2014 Sections P6, P7 and P13 are not shown in the figures but are located at the center of the container shell half way between the bottom end cap and the top end cap. The allowable stress S m for SA-240, Type 304 at 200 F is 20 ksi. Design Pressure Case As identified in Section the canister is to be hydrostatically tested to /-0 psig. This condition is treated as a normal condition, which bounds the maximum pressure of 100 psig expected during normal operational conditions identified in Section A pressure case of 10 psig was evaluated. For this case a 30 sector of the 180 model was used and the liquid region of material was eliminated. The maximum membrane stress intensity from the 14 section cuts was 3.24 ksi and the maximum membrane plus bending stress intensity was 4.83 ksi. For the Normal Conditions of Transport, the margin of safety is.17 for the membrane stress and.21 for the membrane plus bending stress. 1 Foot Side Drop For the side drop each container rests against the inner shell of the LWT cask. The gap elements on the outside surface of the guide bars have two nodes. The outermost nodes are constrained in the radial, tangential and axial direction. This boundary condition represents the inner surface of the LWT cask as rigid, which is a conservative approach since this produces higher loads on the container guide rails. For the side drop case an acceleration of 2 g is applied in the lateral (X) direction. The maximum membrane stress intensity from the 14 section cuts was 2.32 ksi and the maximum membrane plus bending stress intensity was 4.30 ksi. For the Normal Conditions of Transport, the margin of safety is 7.62 for the membrane stress and.98 for the membrane plus bending stress. For additional details refer to item 1 in Section The bearing stress between the guide rail and the inner surface of the LWT cask was also computed. Assuming that the entire weight of the filled container is supported by one guide rail, the bearing stress is ksi. This gives a margin of safety greater than 10. For additional details refer to item 1 in Section Foot Bottom End Drop For the bottom end drop case an acceleration of 2 g is applied in the vertical (Z) direction. The lowest container rests on the spacer ring, which rests on the bottom forging of the LWT cask. The vertical acceleration accounts for the weight of the lowest container; however, the remaining 3 containers are stacked on the top of the lowest container. To account for the weight of the other NAC International

117 NAC-LWT Cask SAR February 2014 three containers an equivalent pressure load is applied to the top of the FEA model for the bottom container. The maximum membrane stress intensity from the 14 section cuts was 4.23 ksi and the maximum membrane plus bending stress intensity was 6.21 ksi. Comparing this to the allowable stress gives a margin of safety of 3.73 for the membrane stress and 3.83 for the membrane plus bending stress. For additional details refer to item 1 in Section The bearing stress between the lowest container and the top surface of the support spacer was computed. The bearing stress is.42 ksi. This gives a margin of safety against the yield strength of The bearing stress between the bottom of the support ring and the bottom of the LWT cask was also checked. This bearing stress is 6.1 ksi, which gives a margin of safety of For additional details refer to item 1 in Section The container wall was also evaluated for potential buckling with a standard closed form solution. The calculated critical buckling stress calculated was 131 ksi. Compared to the calculated compressive stress in the container wall of.42 ksi, the margin of safety is greater than 10. For additional details refer to item 1 in Section The support ring FEA model was utilized to evaluate this case. The maximum membrane stress intensity calculated was ksi and the maximum membrane plus bending stress intensity was ksi. Comparing this to the allowable stress gives a margin of safety of 0.19 for the membrane stress and 0.49 for the membrane plus bending stress. For additional details refer to item 1 in Section Foot Top End Drop For the top end drop case an acceleration of 2 g is applied in the vertical (-Z) direction. The topmost container rests on the closure lid of the LWT cask. The vertical acceleration accounts for the weight of the lowest container; however, the remaining 3 containers are stacked on the top of the lowest container. To account for the weight of the other three containers, an equivalent pressure load is applied to the bottom of the FEA model of the top container. The maximum membrane stress intensity from the 14 section cuts is 4.77 ksi and the maximum membrane plus bending stress intensity is.68 ksi. Comparing this to the allowable stress gives a margin of safety of 3.19 for the membrane stress and 4.28 for the membrane plus bending stress. For additional details refer to item 1 in Section The bearing stress between the topmost container and the bottom surface of the LWT cask closure lid was also checked. The bearing stress is 1.44 ksi, which gives a margin of safety greater than 10. For additional details refer to item 1 in Section NAC International

118 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 The container wall was evaluated for potential buckling with a standard closed form solution. The calculated critical buckling stress calculated was 131 ksi. The calculated compressive stress in the container wall is.42 ksi; therefore, the margin of safety is greater than 10. For additional details refer to item 1 in Section Pressure Case The HEUNL containers are filled at atmospheric pressure. In accordance with Section 4..6, the normal operating pressure is 100 psi. Section identifies the hydro-test pressure to be /-0 psi. For 10 psi internal pressure, the maximum membrane stress was 3.3 ksi and the maximum membrane plus bending was.04 ksi. Conservatively using the allowable stresses for normal conditions, the margin of safety for membrane stress was 3.67 and the margin of safety for membrane plus bending stress was 3.9. Pressure Case Combined with Drop Cases The maximum stress intensities for the pressure case are added absolutely to the maximum stress intensities for the drop cases to get the combined stress intensity. The maximum combined membrane stress intensity is 6.94 ksi and the maximum combined membrane plus bending stress intensity is 9.1 ksi. Comparing this to the allowable stress gives a margin of safety of 1.88 for the membrane stress and 2.1 for the membrane plus bending stress. For additional details refer to item 1 in Section Liquid Sloshing Thermal Stresses Since the heat load for each HEUNL container is less than Watts, there will not be any significant thermally induced stresses for the Normal Condition of Transport. NAC International

119 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Extreme Cold Ambient Conditions (-40 F) Closure Assembly Model The closure assembly model is evaluated for the conditions of bolt preload, normal pressure loading and cold conditions. The bolt preload requirement was determined by the maximum load required to resist the blow-off load for maximum pressure or the maximum load required to compress the O-rings to the point of metal-to-metal contact between the closure lid and the top of the container. The compression load required to compress the seals was larger than that required to resist the blow-off load. The bolt preload requirement was determined to be 18,000 lbs or 3,000 lbs per bolt. The bolt preload for the FEA model was achieved by specifying as an initial strain for the beam elements representing the bolts. Normal Condition Pressure Case The stresses are linearized through the closure lid at two locations; 1) the center of the lid and 2) at the location of the maximum stress which is from the bottom of the counter-bore to the bottom of the lid. These paths are shown in Figure NAC International

120 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure Stress Linearization Paths in Closure Lid The normal condition pressure of 100 psi was applied to the lower surface of the closure lid from the center out to the inner diameter of the inner O-ring. The maximum stress occurs at the counter-bore for the cap screws in the lid. The linearized stresses at the two locations were checked. The maximum membrane stress was 12.2 ksi and the maximum membrane plus bending stress was ksi. Comparing these stresses to the allowable stress gives a margin of safety of 0.64 for membrane stress and 0.63 for membrane plus bending. The contact pressure on the inner seal is checked to ensure that full contact between the closure lid and the inner seal is maintained. This validates the assumption that the pressure load only extends to the inner radius of the inner seal. The maximum axial bolt load calculated for the 100 psi case was 3,162 lbs. Using the thread tensile area, the bolt tensile stress calculated was ksi. The maximum bolt moment calculated was in-lbs. This produces a bending stress of 18.2 ksi. The combined axial plus bending stress is 41. ksi. Bolt Stresses Using an allowable stress of (S m ) BM = 4.0 ksi for SA 70, Type 630 (17-4 PH) at 200 F gives a margin of safety of 2.92 for the axial stress and 2.2 for axial plus bending stress. Thread shear stress The shear stress for the internal threads in the container is limiting since the bolt is SA 70, Type 630 and the container is SA 240, Type 304. The internal thread shear stress for a bolt load of 3,162 lbs is 2.81 ksi. Using the allowable for shear stress gives a margin of safety of For additional details refer to item 1 in Section NAC International

121 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Cold Conditions Since the pressure in the container for cold conditions is 66 psig, it is assumed that this pressure exists underneath the closure lid also. The pressure load is applied from the center of the lid out to the inner radius of the inner seal. The maximum stress occurs at the counter-bore for the cap screws in the lid. The linearized stresses at the two locations were checked. The maximum membrane plus bending stress was ksi. Since this is a displacement controlled load, the allowable stress for membrane plus bending is 3S m. For SA 240, Type 304 at -40 F, S m is 20 ksi. Therefore the margin of safety is 1.08 based on the linearized membrane plus bending stress. The contact pressure on the inner seal is checked to ensure that full contact between the closure lid and the inner seal is maintained. This validates the assumption that the pressure load only extends to the inner radius of the inner seal. The maximum axial bolt load calculated for the cold condition case was,921 lbs. Using the thread tensile area, the bolt tensile stress calculated was ksi. The maximum bolt moment calculated was in-lbs. This produces a bending stress of 6.27 ksi. The combined axial plus bending stress is ksi. Bolt Stresses Using an allowable stress of (S m ) BM = 4.0 ksi for SA 70, Type 630 (17-4 PH) at 200 F gives a margin of safety of 1.09 for the axial stress and 0.2 for axial plus bending stress. Thread shear stress The shear stress for the internal threads in the container is limiting since the bolt is SA 70, Type 630 and the container is SA 240, Type 304. The internal thread shear stress for the bolt load of,921 lbs is.27 ksi. Using the allowable for shear stress gives a margin of safety of For additional details refer to item 1 in Section NAC International

122 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February Fill/Drain Port Model To evaluate the stresses due to cold conditions, two paths are defined along the inner radius of the port passage. These paths are shown in Figure Figure Stress Linearization Paths in Fill/Drain Ports The maximum linearized stresses at these two locations are ksi for membrane stress and ksi for membrane plus bending stress. Since this is a displacement controlled load, the allowable stress for membrane plus bending is 3S m. For SA 240, Type 304 at -40 F, S m is 20 ksi. Therefore the margin of safety for the membrane plus bending stress is For additional details refer to item 1 in Section HEUNL Structural Calculations Canister Structural Evaluations for HEUNL in the NAC-LWT NAC International

123 NAC-LWT Cask SAR February Conclusion Loads generated during normal operations conditions for each basket assembly design result in total equivalent stresses, which each basket body can adequately sustain. Analyses show that all basket-bearing stresses during a side drop are much less than the material yield strength. Column analyses demonstrate that each basket assembly is self-supporting during an end drop. The minimum Margin of Safety, for all basket designs, is as reported in Section for the TRIGA basket; as shown in Table for the DIDO basket; as reported in Section for the GA fuel basket; and as reported in Section for the ANSTO basket. The HEUNL container has a minimum margin of safety of as reported in Section Therefore, it can be concluded that all basket/container designs have sufficient structural integrity for adequate service during normal conditions of transport. NAC International

124 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure Internal Pressure Case 30 Sector Model HEUNL Container 30 Foot Drop Case The HEUNL container is evaluated for both end drops (top and bottom drops) and a side drop. An equivalent acceleration of 61 g is used to evaluate the 30 foot drops. For each drop case, the container and the support ring FEA models are utilized. The linearized stresses are checked at 14 section locations for the container model. The sections used were shown in Figures and , previously. The allowable stresses are based on either S m, which is 20.0 ksi, or S u, which is 66.2 ksi for SA 240, Type 304 at 300 F. The allowable stress for membrane is either 2.4 S m or 0.7 S u, whichever is smaller, and the allowable stress for membrane + bending is either 3.6 S m or 1.0 S u, whichever is smaller. For SA-240, Type 304, the lower allowable stresses are 2.4 S m and 3.6 S m. 30 Foot Side Drop For the side drop each container rests against the inner shell of the of the LWT cask. The gap elements on the outside surface of the guide bars have two nodes. The outermost nodes are constrained in the radial, tangential and axial direction. This boundary condition represents the inner surface of the LWT cask as rigid, which is a conservative approach since this produces higher loads on the container guide rails. For the side drop case an acceleration of 61 g is applied in the lateral (X) direction. The maximum membrane stress intensity from the 14 section cuts was 4.26 ksi and the maximum membrane plus bending stress intensity was 7.82 ksi. This gives a margin of safety greater than 10 for the membrane stress and 7.47 for the membrane plus bending stress. For additional details refer to item 1 in Section NAC International

125 NAC-LWT Cask SAR February Foot Bottom End Drop For the bottom end drop case, an acceleration of 61 g is applied in the vertical (Z) direction. The lowest container rests on the bottom forging of the LWT cask. The vertical acceleration accounts for the weight of the lowest container; however, the remaining 3 containers are stacked on the top of the lowest container. To account for the weight of the other three containers an equivalent pressure load is applied to the top of the FEA model of the bottom container. The maximum membrane stress intensity from the 14 section cuts was ksi and the maximum membrane plus bending stress intensity was ksi. This gives a margin of safety of 3.0 for the membrane stress and 3.83 for the membrane plus bending stress. For additional details refer to item 1 in Section The container wall was also evaluated for potential buckling with a standard closed form solution. The calculated critical buckling stress calculated was 119 ksi. Compared to the calculated compressive stress in the container wall of ksi, the margin of safety is For additional details refer to item 1 in Section The support ring FEA model was utilized to evaluate this case. The maximum membrane stress intensity calculated was ksi and the maximum membrane plus bending stress intensity was ksi. Comparing this to the allowable stress gives a margin of safety of 0.13 for the membrane stress and 0.34 for the membrane plus bending stress. For additional details refer to item 1 in Section Foot Top End Drop For the top end drop case an acceleration of 61 g is applied in the vertical (-Z) direction. The topmost container rests on the closure lid of the LWT cask. The vertical acceleration accounts for the weight of the lowest container; however, the remaining 3 containers are stacked on the top of the lowest container. To account for the weight of the other three containers, an equivalent pressure load is applied to the bottom of the FEA model of the top container. Again the total reaction load was checked to ensure that the weight of all 4 containers was accounted for. The maximum membrane stress intensity from the 14 section cuts was 11.6 ksi and the maximum membrane plus bending stress intensity was 13.7 ksi. This gives a margin of safety of 2.98 for the membrane stress and 3.88 for the membrane plus bending stress. For additional details refer to item 1 in Section The container wall was evaluated for potential buckling with a standard closed form solution. The calculated critical buckling stress calculated was 119 ksi. The calculated compressive stress in the container wall is ksi; therefore, the margin of safety is For additional details refer to item 1 in Section NAC International

126 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Internal Pressure Case Thermal Expansion Closure Assembly Model Accident Condition Pressure Case The stresses are linearized through the closure lid at two locations; 1) the center of the lid and 2) at the location of the maximum stress which is from the bottom of the counter-bore to the bottom of the lid. These paths are shown in Figure The normal condition pressure of 200 psi was applied to the lower surface of the closure lid from the center out to the inner diameter of the inner O-ring. The maximum stress occurs at the counter-bore for the cap screws in the lid. The linearized stresses at the two locations were checked. The maximum membrane stress was ksi and the maximum membrane plus bending stress was ksi. Comparing these stresses to the allowable stress gives a margin of safety of 2.39 for membrane stress and 2.17 for membrane plus bending. The contact pressure on the inner seal is checked to ensure that full contact between the closure lid and the inner seal is maintained. This validates the assumption that the pressure load only extends to the inner radius of the inner seal. The maximum axial bolt load calculated for the 200 psi case was 3,73 lbs. Using the thread tensile area, the bolt tensile stress calculated was 2.97 ksi. The maximum bolt moment calculated was in-lbs. This produces a bending stress of ksi. The combined axial plus bending stress is ksi. NAC International

127 NAC-LWT Cask SAR February 2014 Bolt Stresses Using an allowable stress of (S m ) BM = 4.0 ksi for SA 70, Type 630 (17-4 PH) at 200 F gives a margin of safety of 2.8 for the axial stress and 1.74 for axial plus bending stress. Thread shear stress The shear stress for the internal threads in the container is limiting since the bolt is SA 70, Type 630 and the container is SA 240, Type 304. The internal thread shear stress for a bolt load of 3,73 lbs is 3.18 ksi. Using the allowable for shear stress gives a margin of safety of For additional details refer to item 1 in Section HEUNL Structural Calculations , Canister Structural Evaluation for HEUNL in the NAC-LWT NAC International

128 NAC-LWT Cask SAR February 2014 Table of Contents 3.0 THERMAL EVALUATION Discussion Thermal Properties of Materials Conductive Properties Radiative Properties Convective Properties Technical Specifications of Components Thermal Evaluation for Normal Conditions of Transport Thermal Model Maximum Temperatures Minimum Temperatures Maximum Internal Pressures Maximum Thermal Stresses Evaluation of Package Performance for Normal Conditions of Transport Hypothetical Accident Thermal Evaluation Finite Element Models Package Conditions and Environment Package Temperatures Maximum Internal Pressure Maximum Thermal Stresses Evaluation of Package Performance for Hypothetical Accident Thermal Conditions Assessment of the Effects of the Fission Gas Release in the Fire Accident Condition Failed Metallic Fuel Basket SCOPE Evaluations NAC International 3-i

129 NAC-LWT Cask SAR February 2014 List of Figures Figure HEATING Normal Transport Conditions Thermal Model Figure Design Basis PWR Fuel Assembly Axial Flux Distribution Figure ANSYS MTR Fuel Design Basis Heat Load Thermal Model (Uniform 30-Watt/Element Configuration Heat Load) Figure MTR Fuel Variable Decay Heat ANSYS Thermal Model Figure 3.4- Thermal Resistance Model for TRIGA Fuel Elements Figure Modeling Details for the MTR Fuel Assembly Resting on the Surface of the NAC-LWT MTR Basket Figure Finite Element Thermal Model for TRIGA Fuel Cluster Rods Figure Details of the TRIGA Fuel Cluster Rods in the Finite Element Model Figure Individual TRIGA Fuel Cluster Rod Finite Element Model Details Figure PWR and BWR High Burnup Fuel Rods Normal Condition ANSYS Thermal Model (Condition 1) Figure Close-up of PWR and BWR High Burnup Fuel Rods Normal Figure Condition ANSYS Thermal Model PWR and BWR High Burnup Fuel Rods Normal Condition ANSYS Thermal Model (Condition 2) Figure Finite Element Thermal Model for MTR Fuel Element Figure Detailed DIDO Basket Module Finite Element Model Figure Detailed DIDO Fuel Assembly Model Figure ANSYS Model for BWR 7 7 Fuel Lattice with 2 High Burnup Fuel Rods Figure Fuel Rod Locations in the Thermal Model for Damaged Fuel Figure Finite Element Model for TPBARs Figure Finite Element Model for MOATA Plate Fuel ANSTO Figure Finite Element Model for Mark III Spiral Fuel ANSTO Figure Finite Element Model for HEUNL in NAC-LWT Cask Figure 3.-1 Transient Thermal Analysis Finite Element Model of the NAC-LWT Figure 3.-2 Top Region of the ANSYS Model Figure 3.-3 Bottom Region of the ANSYS Model Figure 3.-4 Figure 3.- Figure 3.-6 Figure 3.-7 Figure 3.-8 Figure 3.-9 Figure Temperature History of NAC-LWT O-Rings and Valves in the Hypothetical Fire Event Temperature History of NAC-LWT Components in the Hypothetical Fire Event MTR Fuel Design Basis Heat Load Fire Accident ANSYS Thermal Model (Uniform 30-Watt/Element Configuration Heat Load) MTR Fuel Variable Heat Load Fire Accident ANSYS Thermal Model (120-Watt/70-Watt/20-Watt Configuration Heat Load) Temperature History in the MTR Fuel Variable Heat Load Fire Accident Analysis Location of the Maximum Temperature in the MTR Fuel Variable Heat Load Temperature History for the TRIGA Fuel Cluster Rods Design Basis Heat Load Fire Accident Analysis NAC International 3-ii

130 NAC-LWT Cask SAR February 2014 List of Figures (continued) Figure Temperature History of NAC-LWT Cask Components with PWR and BWR High Burnup Fuel Rods in the Hypothetical Fire Event Figure End of Fire Temperatures of the Alternate Port Cover Components Figure Transient Temperatures of the Alternate Port Cover Components Figure Model for the HEUNL Fire and Cool Down Analysis (with Ribs/Slide Bars Added) Figure 3.-1 Model Detail for the HEUNL Fire and Cool-Down Analysys (with Ribs/ Slide Bars Added) Figure Temperature History of HEUNL Liquid in the Hypothetical Fire Event Figure Temperature History of HEUNL Container Shell in the Hypothetical Fire Event Figure Failed Fuel Basket SCOPE Input Figure Failed Fuel Basket SCOPE Output Figure Nine Failed Metallic Fuel Rods SCOPE Input Figure Nine Failed Metallic Fuel Rods SCOPE Output NAC International 3-iii

131 NAC-LWT Cask SAR December 2012 Revision LWT-12E List of Tables Table Thermal Properties of Type 304 Stainless Steel Table Thermal Properties of 6061-T6 Aluminum Alloy Table Thermal Properties of Dry Air Table Thermal Properties of Chemical Copper Lead Table 3.2- Thermal Properties of 6 Percent Ethylene Glycol Solution Table Thermal Properties of BISCO FPC (Fireblock Silicone Foam) Table Thermal Properties of Helium Table Fiberfrax Ceramic Fiber Paper, Grades 0, 880, and Table Temperatures for Metallic Fuel Transport Table Maximum Component Temperatures Design Basis PWR Fuel Table Limiting Cold Case Component Temperatures Design Basis PWR Fuel Table Fission Product Gas Inventories and Pressures for Design Basis PWR Fuel Assembly Table 3.4- NAC-LWT Cask Thermal Performance Summary Table MTR Fuel Maximum Component Temperatures Normal Transport Condition Table PWR Rods (2 Total) Maximum Component Temperatures Normal Transport Condition Table TRIGA Fuel Element Maximum Component Temperatures Normal Conditions of Transport Table TRIGA Fuel Cluster Rod Temperatures Normal Conditions of Transport Table PWR and BWR High Burnup Fuel Rods Maximum Component Temperatures Normal Transport Condition Table Fission Product Gas Inventories and Pressures for the Exxon 7 7 BWR Fuel Assembly Table DIDO Fuel Maximum Component Temperatures Normal Transport Condition Table General Atomics IFM Maximum Component Temperatures Normal Transport Condition Table PWR and BWR High Burnup Fuel Rods in a Fuel Assembly Lattice Maximum Component Temperatures Normal Transport Condition Table Maximum Component Temperatures for High Burnup Fuel Rods with Table Damaged Fuel Rods in a Rod Holder Maximum Component Temperatures for TPBAR Shipment Normal Conditions of Transport Table Maximum Component Temperatures PULSTAR Fuel in MTR Basket Table PULSTAR Fuel Dimensions Table PULSTAR Payload Volume Summary Table PULSTAR Fuel Assembly Fission Product Gas Inventory Table PULSTAR Fuel Element Normal Condition Internal Pressure Summary Table Maximum Component Temperatures MOATA Plate Fuel and Mark III Spiral Fuel in ANSTO Basket Table Cask and Rod Condition NAC International 3-iv

132 NAC-LWT Cask SAR February 2014 List of Tables (continued) Table Gas Isotopics (Gram) Table Molar Gas Quantity Table Maximum Cask Cavity Pressure Table 3.-1 Maximum Component Temperatures ( F) During the Fire Accident (Design Basis PWR Fuel, 2. kw Heat Load) Table 3.-2 MTR Fuel Fire Accident Maximum Temperatures ( F), 10 Fuel Plate/120W Element Case (Bounding Configuration) Table 3.-3 TRIGA Fuel Fire Accident Maximum Temperatures ( F) Table 3.-4 PWR and BWR High Burnup Fuel Rods Fire Accident Maximum Temperatures ( F) Table 3.- Maximum Component Temperatures for High Burnup Fuel Rods in a Rod Holder with Damaged Fuel Rods for the Fire Accident Table 3.-6 TPBAR Fire Accident Maximum Temperatures NAC International 3-v

133

134 NAC-LWT Cask SAR February THERMAL EVALUATION 3.1 Discussion This chapter summarizes the thermal analyses, which are performed to demonstrate fulfillment of the thermal capability requirements established in 10 CFR 71. The NAC-LWT cask is designed to safely contain irradiated nuclear fuel and other radioactive materials under a variety of normal transport conditions (as described in 10 CFR 71.71) and accident conditions (as described in 10 CFR 71.73). In order to verify the adequacy of the design, detailed analyses of a reference design PWR shipment are performed considering extreme normal transport and hypothetical accident conditions. The NAC-LWT cask is designed to transport one intact PWR fuel assembly; up to 2 intact BWR fuel assemblies; up to 2 individual PWR or BWR rods (including up to 14 fuel rods classified as damaged); up to 16 PWR MOX fuel rods (or a combination of PWR MOX and UO 2 PWR fuel rods); up to 42 MTR and DIDO fuel elements; up to 140 TRIGA fuel elements or 60 TRIGA fuel rod clusters; up to 300 TPBARs (of which two can be prefailed), up to segmented TPBARs; or up to 700 PULSTAR fuel elements (intact or damaged); and metallic fuel. The PULSTAR fuel will be loaded in the 28 MTR basket and consist of intact fuel assemblies, intact fuel rods loaded in fuel rod inserts or fuel cans, or intact or damaged fuel and nonfuel components or fuel assemblies loaded in fuel cans. High burnup PWR/BWR fuel rods may be placed in a rod holder or in a fuel assembly lattice. Damaged PWR/BWR fuel rods must be placed in a rod holder. Four (4) HEUNL containers, either filled to capacity, partially filled or empty, will be loaded into the NAC-LWT cask enclosed in an ISO container. High burnup PWR/BWR/PWR MOX fuel rods are placed in a rod holder (a rod holder is the term generally used in this chapter to describe a PWR/BWR Rod Transport Canister with a 4 4 or a insert as presented on the drawings provided in Section 1.4). The high burnup PWR and BWR rods may also be placed in a fuel assembly lattice. Damaged PWR/BWR fuel rods must be placed in a rod holder. The 16 PWR MOX fuel rods are required to be placed in a rod holder with a insert. Along with the maximum 16 PWR MOX rod contents (or combination of PWR MOX and UO 2 PWR fuel rods), the remaining tubes may be loaded with burnable poison rods or other intact components with negligible heat loads (total additional heat load of less than 10 watts). An intact PWR fuel assembly with a maximum decay heat load of 2. kw is used in a majority of the thermal analyses. The failed fuel basket analysis in Section 3.6 uses a decay heat load of 30 Watts. The 42 MTR fuel assembly basket in Section uses a decay heat load of 1.26 kw. A decay heat load of 1.0 kw is conservatively used for the TRIGA fuel basket analysis NAC International 3.1-1

135 NAC-LWT Cask SAR December 2012 Revision LWT-12E and a decay heat load of kw is used for the TPBAR basket analysis. The maximum heat load for the PULSTAR fuel is kw per cask. The maximum heat load for the maximum number of 16 PWR MOX fuel rods is 2.3 kw per cask (143 W per PWR MOX rod). The maximum heat load for four (4) HEUNL containers filled to capacity is Watts per cask. As long as the decay heat load is within the design limit of 2. kw, any of the fuel types and other radioactive material that the NAC-LWT cask is analyzed to transport are bounded by the cask body thermal analyses of the design basis PWR assembly. The primary heat rejection design criteria for the NAC-LWT cask are that: 1. Components important to safety shall not be subjected to temperatures outside their safe operating ranges. 2. Thermally induced stresses in the cask containment (in combination with pressure and various load condition stresses) shall not cause degradation of the cask containment capability. The first criterion is fulfilled by thermal analysis results, which show that components important to safety are maintained within their safe operating ranges. In the event that the temperatures of the components important to safety fall outside the safe operating ranges, it is assumed that the component has failed. Temperatures of components important to safety may not fall outside the safe operating range during normal transport conditions. There are three important safety components that are subject to this thermal criterion the tetrafluoroethylene (TFE), Viton, and metallic O-ring seals; the lead gamma shield; and the 6 % ethylene glycol and water neutron shield. An additional thermal consideration is associated with the liquid neutron shield tank the reduction in neutron shielding capability caused by thermal contraction. An expansion tank is provided to ensure that the neutron shield tank remains full despite worst case contraction of the liquid in the tank during cooling. The method used by the expansion tank to keep the neutron shield tank full is described in Section The second criterion is fulfilled by the structural analysis of Chapter 2, which shows that combined load stresses (including thermally induced stresses) are less than the limits stated in Section The thermal analyses were performed for a 0.2-inch thick neutron shield tank shell, while the actual fabricated thickness is only 0.24 inches (6mm). The shell thickness difference of 0.01 inches equates to only a F T; therefore, the analyses reported in this chapter are valid. NAC International 3.1-2

136 NAC-LWT Cask SAR December 2012 Revision LWT-12E T a T b 0.1kW kW kW kW 671 F 387 F 12.7 F 228 F 222 F F T T T = 14 F total a b where: T a : is the temperature difference between the maximum contents temperature and PWR insert for the TPBARs in the PWR/BWR Rod Transport Canister configuration. T b : is the temperature difference across the TPBAR basket to the inner surface of the inner shell for the TPBARs in the PWR/BWR Rod Transport Canister configuration. T total : is the temperature difference from the inner surface of the inner shell to the maximum contents temperature. The maximum contents temperature for the TPBARs in the PWR/BWR Rod Transport Canister configuration is calculated as follows for the normal conditions of transport. T max contents Tis T = 222 F +14 F = 236 F max total where: Tis max : is the assumed maximum inner shell temperature for the TPBARs in the PWR/BWR Rod Transport Canister configuration The maximum contents temperature for the NAC-LWT transport cask loaded with TPBAR fuel, the PWR/BWR Rod Transport Canisters, the PWR insert and the TPBAR basket is lower than the maximum temperature for the 300 TPBARs in the TPBAR basket analysis of Section (236 F versus 290 F). Therefore, the component temperatures for the 2 TPBARs in the Rod Transport Canister configuration are bounded by the results of Section , which are summarized in Table Thermal Evaluation of HEUNL Thermal analysis of the NAC-LWT with HEUNL containers is performed using the general purpose ANSYS computer code and a two-dimensional finite element model representing a 180- degree cross section of the LWT cask. The model represents the cask contents inside the cask inner shell. The NAC-LWT is supported in an ISO container with solar insolance applied on the surface of the ISO container, and the NAC-LWT is considered to be insulated from the NAC International

137 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 environment (only for the normal conditions of transport steady state condition). The gas inside the ISO container is air. The ambient temperature is 100 F with solar insolance. A 180-degree two-dimensional planar model, as shown in Figure , is generated due to the symmetry of the geometry and the heat load. The HEUNL container is modeled with stainless steel properties. The gap between the LWT inner shell and the HEUNL container is air without radiation. The total heat load of W for the whole cask is used and is distributed over the cavities of the four (4) containers. The heat generation rate applied to the liquid in the two-dimensional model is 0.0 W/liter ( Btu/hr-in3), based on the total heat load. A constant temperature of 134 F is applied to the outer surface of the model, which corresponds to the maximum inner shell temperature. This maximum cask inner shell temperature is obtained using the two-dimensional ANSYS model for normal condition (Condition 1) from Section after deleting all elements inside the cask inner shell. A heat flux computed based on a heat load of W/cask, as follows, is applied to the inner surface of the cask inner shell of this two-dimensional model to obtain the maximum cask inner shell temperature of 134 F. where: H _ flux Btu /(hr in. ) Watts is the heat load for a container; inches is the ID of the LWT cask inner shell; 30 inches is conservatively used for the axial length for one container assembly. The maximum temperature in the HEUNL model is computed to be 139 F. This confirms that for normal condition of transport, the HEUNL remains in the liquid state and that the maximum HEUNL container temperature is significantly lower than the allowable temperature of 800 F for stainless steel (Table ). Maximum temperature of slide bars of the HEUNL container is bounded by the liquid temperature of 139 F, which is lower than the allowable temperature of 180 F for. This allowable temperature is established based Specifications. The heat load of the HEUNL (12.88 W) is bounded by the heat load of the MTR fuel (1.26 kw, Section 3.1). Therefore, the maximum temperatures of the cask components for the MTR contents (Condition 1, Table 3.4-6) bounds the maximum temperatures for the cask components for HEUNL. NAC International

138 NAC-LWT Cask SAR December 2012 Revision LWT-12E modeled at 19% or greater 23 U enrichments. The negligible buildup of alpha decay gases makes the choice of cool time insignificant to the analysis results. Fission product and actinide gas inventories in grams extracted from the SAS2H outputs are listed in Table Fission gas inventories in grams are converted to inventories in moles using Avogadro s number and the atomic mass of each isotope. As illustrated in Table 3.4-2, the total molar quantity of fission gas does not vary significantly between various enrichment levels for a given fuel type. The MTR elements produce the bounding fission gas content. The majority of fission gases, ~8%, is comprised of Xenon isotopes. There is no significant quantity of helium or tritium Normal Condition Pressures Using Dalton s Law of partial pressures, the NAC-LWT cask cavity pressure may be calculated by first determining the partial pressure of the released fission gases and adding it to the cask backfill gas. Gas available for release from the fuel elements depends on the fueled surface area exposed by clad-through damage. Cask Backfill Gas Based on the ideal gas law, the pressure of the cask backfill gas is simply the ratio of the backfill temperature at testing (assumed at standard temperature) to the operating condition temperature. T PCask Backfill =14.7 psi T Operating Temperature Standard Conditions Partial pressures of the cask backfill at normal and accident conditions are 23.8 psi and 2.9 psi for ANSTO/DIDO and MTR payloads, respectively. Fission Gas The pressure of rod fission gas is calculated using release fraction (or surface area fraction assuming 100% release from the unclad fuel meat), the quantity of fission gas in the element, the cask cavity backfill temperature and the cask cavity gas temperature. n Fission Gas Moles (Cask) Release Fraction nrt P = V For the MTR LEU fuel, a sample calculation based on a 0% surface area exposed with a 100% gas release from the exposed surface area is: NAC International 3.4-

139 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 P P Fission Gas Fission Gas Normal Pressure moles elements liters atm % K = = element cask k mole liters 1.61 atm 23.7 psi Normal and accident pressures can now be generated at the various release/surface area fractions. Only LEU MTR and DIDO elements are summarized as they produce the maximum MTR and DIDO fission gas quantities and, therefore, pressures. Results are summarized in Table as partial pressure of the fission gas and total system pressure in psia and psig. To meet a 0 psig system structural analysis limit, a maximum 80% of the MTR and 100% of the DIDO/ANSTO gases can be assumed to escape from the plates. As MTR plates with significant through-clad damage will have released a portion of their gas inventory prior to transport (i.e., during in-core use, storage and cask vacuum drying), system pressure is expected to remain below 0 psig when considering all fission gas released from the MTR plates. Note that experimental data summarized in WSRC-TR , October 1998, Bases for Containment Analysis for Transportation of Aluminum Based Spent Nuclear Fuel, Section.3.1, indicates no significant release of gases from exposed fuel material occurs at the temperature (200 C C) of the NAC-LWT cask cavity and contents with aluminum-based fuel payload Maximum Internal Pressure for HEUNL Contents Cask Containment NAC International 3.4-6

140 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February HEUNL Container 3.4. Maximum Thermal Stresses The conditions within the range of normal transport conditions and fabrication that result in the limiting combination of thermal gradient and isothermal stresses have been evaluated. The analyses are performed in Sections 2. through 2.7. The resulting isothermal temperature plots are presented in Section Evaluation of Package Performance for Normal Conditions of Transport Section 3.4 provides analyses of the NAC-LWT cask thermal performance for normal transport conditions. The analyses demonstrate that the NAC-LWT cask thermal performance meets the criteria of 10 CFR 71 for normal transport conditions. The maximum fuel rod cladding temperature under normal transport conditions is 472ºF. This is well below the temperatures that can cause fuel rod cladding deterioration. Components important to safety remain within their safe operating ranges (Section 3.3) during normal transport conditions. Thermally induced stresses (in combination with pressure and mechanical load stresses) are less than allowable stresses as shown in Section 2.6. Thus, the analyses of Section 3.4 demonstrate that the NAC-LWT cask fulfills the heat rejection criteria established in Section 3.1 for normal transport conditions. NAC International 3.4-7

141 NAC-LWT Cask SAR December 2012 Revision LWT-12E Figure HEATING Normal Transport Conditions Thermal Model NAC International 3.4-8

142 NAC-LWT Cask SAR February 2014 configurations for the ANSTO-DIDO basket assembly. Therefore, for the fire accident condition, the same basis would confirm that the fuel and component temperatures for the fire accident conditions evaluated in Section for DIDO fuel and Section for ANSTO fuel types are bounding for the maximum fuel temperature in the conditions of the ANSTO- DIDO basket assembly Evaluation for TPBARs in the PWR/BWR Rod Transport Canister Similar to Section , the maximum heat load of TPBARs in the Rod Transport Canister is bounded by the maximum heat load of the MTR fuel. Therefore, in the accident condition, the maximum temperatures of the cask components for the MTR contents will bound the maximum temperatures for the cask components for the TPBAR contents. It is conservative to use the results of the fire transient evaluated in Section for the cask inner shell temperature. The maximum content temperature (T max ) for the TPBARs in a Rod Transport Canister for the accident conditions are determined by adding the temperature difference (ΔT component ) between the cask inner shell and the maximum component temperature for normal conditions to the maximum accident cask inner shell temperature (T inner shell ) obtained from the MTR evaluation. The maximum component temperature is computed as follows. Component ΔT 1 component (ºF) T 2 inner shell (ºF) T max (ºF) TPBAR See Section See Table 3.-2 The computed maximum contents temperature is less than for the TPBAR analysis of Section Therefore, the component temperatures, namely, the aluminum basket and TPBARs, for the fire accident condition are bounded by the results of Section Evaluation of HEUNL Temperatures in the HEUNL container during the fire accident were determined using two ANSYS finite element models of the NAC-LWT cask for HEUNL, one for the initial condition (Model 1) and one for the fire transient analysis (Model 2). The model used for the initial condition (Model 1) is a combination of the model described in Section and the cask model described in Section with ISO container. The models are combined by using ANSYS constraint equations to tie the dissimilar meshes. As shown in Figure , the slide bars and ribs are conservatively modeled as air in the Model 1. The model used for the fire transient analysis (Model 2) is also a combination of the model from Section and the NAC International 3.-13

143 "NAC PROPRIETARY INFORMATION" NAC-LWT Cask SAR REMOVED February 2014 model from section with modifications. The slide bars and ribs are added in the Model 2 to allow more heat transfer into the cask, as shown in Figure and Figure Thermal properties for the slide bars are listed below. Thermal Conductivity Density Specific Heat 2 2 The initial condition for the fire transient analysis is the steady state condition for the normal transport condition, as described in Section The LWT cask loaded with HEUNL containers is inside the ISO container. The ambient temperature is 100 F with solar insolation. The gas in the NAC-LWT cask cavity is considered to be air. The same heat load of 12.88W as used for normal transport condition is utilized. The cask is not in the ISO container as designed for the 30 foot accident drop. The fire is to occur after the drop and pin puncture accidents. At the start of the fire accident, the steam pressure and/or the pin puncture will force the neutron shield to be empty, thus allowing the outer shell of the neutron shield to radiate to the outer surface of the outer cask shell. The fire condition is conservatively applied to the outer surface of the neutron shield shell. The expansion tank is not considered in the accident conditions. The fire conditions are identical to those described in Section NAC International 3.-14

144 NAC-LWT Cask SAR February Maximum Internal Pressure Maximum Internal Pressure for Design Basis Fuel in Accident Conditions The accident internal pressure is calculated assuming an accident with 100 percent fuel rod failure combined with the design basis fire described in 10 CFR 71. The fuel rod failure assumes 30 percent of the fission gas and 100 percent of the backfill gas escapes the ruptured fuel rods. The internal pressure due to the 100 percent fuel rod rupture is calculated using the method described in Section The total cask pressure of the cask backfill and failed fuel rods is calculated by a two step procedure. First, the pressures documented under normal conditions in Section are adjusted to include the increased total free volume associated with 100% fuel rod failure. Then, the revised cask pressure at normal operating temperature is adjusted to accident condition temperatures. Adjusting the partial pressure of the cask backfill: P cask where: P initial V V cask total P initial = 2.8 psia (normal condition temperature adjusted cask backfill pressure) V cask =.196 ft 3 (147,134 cm 3 ) [Section 3.4.4] V rod void = 8,123 cm 3 [Section 3.4.4] V total = 1,27 cm 3 (V cask + V rod void ) P 147,134cm 2.8 psia 1,27cm cask 3 P cask 24.4 psia Adjusting the partial pressure of the fuel rod backfill and fission gases: P where: P initial fuelrods P initial V V rod void total 3 = 1,21.3 psia (fuel rod backfill pressure of psia plus fission gas pressure of 0.30 x psia) V rod void = 8,123 cm 3 V total = 1,27 cm 3 NAC International 3.-1

145 NAC-LWT Cask SAR February 2014 P P 8,123.28cm 1,21.3 psia 1,27cm fuelrods 3 fuelrods 79.6 psia 3 Summing the two partial pressures yields the total cask pressure at normal operating condition temperature: P Total P Total P cask P fuelrods 24.4 psia 79.6 psia P Total psia The fuel cladding has the highest temperature of any barrier with which the gas comes in contact during a design basis fire. As shown in Section , the maximum average cavity gas temperature is 60 F during the fire accident condition. For conservatism, a temperature of 667 F is used in the calculation of the maximum accident condition internal pressure. Given that the internal volume of the NAC-LWT Cask remains constant during the fire, the resultant pressure is proportional to the temperature change according to the ideal gas law: T 2 P 2 P1 T1 Thus, for the design basis fire: P fire o 1127 R psia o 932 R P fire 12.8 psia High Burnup Fuel Rod Canister Maximum Internal Pressure The high burnup fuel rod canister maximum internal pressure in the accident conditions is calculated assuming 100 percent fuel rod failure combined with the design basis fire maximum temperature. The fuel rod failure assumes release of 30 percent of the fission gas and 100 percent of the backfill gas. The canister internal pressure is calculated using the method described in Section , with the BWR used as the bounding fuel type for the analysis. The total canister pressure is calculated in two steps. First, the pressures documented under normal conditions in Section are adjusted to include the increased total free volume associated with 100 percent fuel NAC International 3.-16

146 NAC-LWT Cask SAR February 2014 rod failure. Then, the canister pressure is adjusted to account for the accident condition temperature. The partial pressure of the canister volume is calculated by: P canister P initial V V canister total where: P inital = V canister V void = V void = V total = 29.3 psia (from earlier) = 28.2 liters (from earlier) liters (from earlier) 2*V void + V canister = 30.2 liters 30.2 liters Therefore, P canister is equal to 27.4 psia. The partial pressure of the fuel rods is calculated by: P fuel rods P initial V V fuel rods total where: P initial = 1,42 psia (earlier from Section ) V fuel rods = V fuel rods 2*V void = ~1.97 liters (at 100% of the total fuel rod volume) V total = 30.2 liters (V canister + (2*V void )) and then: P fuel rods 1.97 liters 1,42 psia ~ 94 psia 30.2 liters P total P canister P fuel rods 27.4 psia ~ 94 psia ~121psia (~8.2 atm) For the 100% fuel rod failure and the design basis fire accident temperature of 72 F, the pressure is calculated by multiplying the 100% rod failure pressure by the inverse ratio of the normal condition temperature (88.7 K) to the accident temperature (68.1 K). The pressure thus calculated is 13 psia (~9.2 atm) NAC International 3.-17

147 NAC-LWT Cask SAR February Rod Maximum Internal Pressure-Cask Cavity Using the same methodology used to calculate the cavity pressure in Section , the pressure from the 100% fuel rod failure and the design basis fire accident temperature of 72 F is calculated using the cask cavity free gas volume (89.32 liters from earlier). The resulting pressure in the cask cavity, assuming that the gases within the canister are released to the cask cavity, is 67 psia (~4. atm) TPBAR Shipment Cask Cavity Internal Pressure-Accident Conditions Employing the normal condition TPBAR result in Section of 276 psig for the 300 production TPBAR content condition and adjusting system pressure to the average accident gas temperature of 38 F yields a maximum accident condition pressure of 322 psig. For a period of one year following the 90-day cooldown, the pressure for this content condition increases to 337 psig. As discussed in Section , these values bound those of the up to 2 TPBAR transport configuration within the rod holder. The rod holder combination contains significantly lower releasable gas quantities at similar free volume. Utilizing the same assumptions as presented in Section and the post-accident thermal conditions discussed above, the pressure for the segmented TPBARs in the waste container will be less than 7 psia and, therefore, bounded by the 300 TPBAR content condition Maximum Internal Pressure for PULSTAR Fuel Payload Maximum internal pressures under accident conditions are calculated using the same methodology as that employed in Section The accident condition temperature is set to 394 F, and 100 percent of the fuel rods are assumed to fail. The resulting calculated pressures are summarized as follows. Free Volume Pressure Description (liters) (atm) (psia) (psig) Cask Pressure -28 Intact Assemblies Cask Pressure -14 Intact Assemblies and 14 Cans Can Pressure - PULSTAR Failed Fuel Can NAC International 3.-18

148 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February Maximum Internal Pressure for 16 PWR MOX/UO 2 Fuel Rods in a Rod Holder Using the same methodology used to calculate the cavity pressure in Section , the pressure from the 100% fuel rod failure with 100% gas release and the design basis fire accident temperature of 72 F is calculated. The resulting pressure in the cask cavity is 6.3 psig (80.0 psia,.4 atm) Maximum Internal Pressure for Aluminum-Based Fuels The maximum normal condition 100% fission gas release MTR payload is evaluated for accident pressure. This payload bounds the remaining aluminum based fuel payloads. The 100% release normal condition pressure in Section is simply increased by the ratio of accident (28K) to normal (470K) temperature. P Accident = P Normal T T Accident Normals 73.1psia 28K 470K 82.1psia 67.4psig As the DIDO accident temperature is higher than the MTR temperature, the DIDO value is used as the ratio basis. Maximum accident pressure for aluminum-based fuel is conservatively calculated to be 68 psig Maximum Internal Pressure for HEUNL Contents Cask Containment NAC International 3.-19

149 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February HEUNL Container 3.. Maximum Thermal Stresses The most severe thermal stress conditions that occur during the fire test and subsequent cooldown have been evaluated. For conservatism, an internal pressure of 168 psig is used, in the analysis that is performed in Section The temperatures corresponding to the maximum thermal stresses are reported in Table Evaluation of Package Performance for Hypothetical Accident Thermal Conditions The NAC-LWT cask thermal performance has been assessed for the hypothetical accident, as specified in 10 CFR 71. The O-rings and the lead gamma shields remain within their safe operating ranges. The cask does not suffer any adverse structural consequences as a result of the thermal considerations of the hypothetical accident. The NAC-LWT cask maintains containment and does not exceed the dose rate limits of 49 CFR 173 as a result of the hypothetical accident. NAC International 3.-20

150 NAC-LWT Cask SAR February Assessment of the Effects of the Fission Gas Release in the Fire Accident Condition During the fire, the release of the fission gas is expected to reduce the effective thermal conductivity of the gas in the cavity or inside the sealed canisters. To assess the reduction of the thermal conductivity, the helium conductivity is factored by the ratio of the conservative initial fill pressure of 6 psia (Section 3.4.4) for the PWR fuel assemblies and the end of life pressure (which contains the fill gas plus the fission gas release) of 1,21 psia (Section 3..4). This ratio is computed to be A conservative ratio of 0.24 is applied to the conductivity of helium, assuming that all fission product gases have a conductivity of zero. For the temperatures shown, which envelope the maximum temperatures of the cavity gas in the accident condition, the reduced helium properties are larger than the thermal conductivity of air. This is bounding because, as shown in Table 4.2-2, the volume of fission product gas produced by the design basis PWR assembly is higher than that for any other fuel loading. The data below (Krieth) reflects the comparison of the air conductivity and the factored helium conductivity. Temperature ( F) Air Conductivity (K air ) (Btu/hr-in-F) Helium Conductivity (Btu/hr-in-F) Factored Helium Conductivity (K He ) (Btu/hr-in-F) Ratio K He / K air The analyses performed for the contents employed air as the gas in the cavity and containers for the accident condition. This demonstrates that the evaluation of the accident condition using air bounds the reduced helium properties case. NAC International 3.-21

151 NAC-LWT Cask SAR February 2014 Figure 3.-1 Transient Thermal Analysis Finite Element Model of the NAC-LWT Cask Lid Support Plate Inner Shell Expansion Tank Radial Lead Outer Shell Neutron Shielding Neutron Shield Shell Bottom Lead Bottom Plate NAC International 3.-22

152 NAC-LWT Cask SAR February 2014 NAC International Figure 3.-2 Top Region of the ANSYS Model Note: Fire Block is either BISCO FPC or UNIFRAX Fiberfrax Ceramic Fiber Paper Fire Block (Material No.2)

153 NAC-LWT Cask SAR February 2014 NAC International Figure 3.-3 Bottom Region of the ANSYS Model Note: Fire Block is either BISCO FPC or UNIFRAX Fiberfrax Ceramic Fiber Paper Fire Block (Material No.2)

154 NAC-LWT Cask SAR February 2014 Figure 3.-4 Temperature History of NAC-LWT O-Rings and Valves in the Hypothetical Fire Event 1. Temperature of the Valves 2. Temperature of the O-Rings 1 2 NAC International 3.-2

155 NAC-LWT Cask SAR February 2014 Figure 3.- Temperature History of NAC-LWT Components in the Hypothetical Fire Event 1. Temperature of the Cask Outer Surface 2. Temperature of the Neutron Shield 3. Temperature of the Radial Lead Gamma Shield 4. Temperature of the Bottom Lead Gamma Shield. Temperature of the Inner Stainless Steel Shell NAC International 3.-26

156 NAC-LWT Cask SAR February 2014 Figure 3.-6 MTR Fuel Design Basis Heat Load Fire Accident ANSYS Thermal Model (Uniform 30-Watt/Element Configuration Heat Load) Outer Surface Air Void Outer Shell Air Gap Lead Gamma Shield Inner Shell Cavity Air Fuel Basket 30 W Fuel Elements NAC International 3.-27

157 NAC-LWT Cask SAR February 2014 Figure 3.-7 MTR Fuel Variable Heat Load Fire Accident ANSYS Thermal Model (120-Watt/70-Watt/20-Watt Configuration Heat Load) Outer Surface Air Void Outer Shell Air Gap Lead Gamma Shield Inner Shell Cavity Air Fuel Basket 70 W Fuel Element 120 W Fuel Element 20 W Fuel Element Cavity Air NAC International 3.-28

158 NAC-LWT Cask SAR February 2014 Figure 3.-8 Temperature History in the MTR Fuel Variable Heat Load Fire Accident Analysis Figure F-3: Time Histories for Three NonUniform MTR Fuel Assemblies, Condition Fuel Plates per Assembly, Worst-Case Fuel Plate Dimensions OUTER 00 Temperaure, F FUEL BASKE INNER OUTER Time, hr Note: 120-Watt / 70-Watt / 20-Watt Configuration Heat Load. Cavity gas is air with fire applied to cask surface. NAC International 3.-29

159 NAC-LWT Cask SAR February 2014 Figure 3.-9 Location of the Maximum Temperature in the MTR Fuel Variable Heat Load Tmax = F 2.42 inches Inner Surface of Basket E E F E F E G G G G EF H H EF G H F E F E H G F FE F G F H E F G F E H F G H I I F E G I H F E MX G IH F E G IH F E G F IH F E G I I H F H H G E G F G F E G F GG E G G G F F E F E F E F E F E F F F E E E E ANSYS.2 OCT :47:07 PLOT NO. 4 NODAL SOLUTION TIME=9.14 TEMP SMN =1 327 SMX = A = B =206.4 C = D = E = F = G = H = I = NAC International 3.-30

160 NAC-LWT Cask SAR February 2014 Figure Temperature History for the TRIGA Fuel Cluster Rods Design Basis Heat Load Fire Accident Analysis (Uniform 30 watt/basket cell or 210 watt/basket section or 1.0 kw total heat load) (Cavity gas: Air, Fire is Applied to the Cask Surface) 1 ANSYS.2 DEC :7:14 PLOT NO. 1 TR_TM ZV =1 DIST=.7 XF =. YF =. ZF =. Z-BUFFE R COL 1 max temperature of fuel NAC International 3.-31

161 NAC-LWT Cask SAR February 2014 Figure Temperature History of NAC-LWT Cask Components with PWR and BWR High Burnup Fuel Rods in the Hypothetical Fire Event 1. Average Temperature of Cask Cavity Gas 2. Temperature of the Fuel Cladding 3. Temperature of the Can Weldment 4. Temperature of the Aluminum Structural Component. Temperature of the Pin Tube NAC International 3.-32

162 NAC-LWT Cask SAR February 2014 Figure End of Fire Temperatures of the Alternate Port Cover Components Temperature ( ºF) Bolt Head Bolt Threads Bore Seal Face Seal Time (hrs) NAC International 3.-33

163 NAC-LWT Cask SAR February 2014 Figure Transient Temperatures of the Alternate Port Cover Components Temperature (F) Bolt Head Bolt Threads Bore Seal Face Seal Time (hrs) NAC International 3.-34

164 "NAC PROPRIETARY INFORMATION" NAC-LWT Cask SAR REMOVED February 2014 Figure Model for the HEUNL Fire and Cool-Down Analysis (with Ribs/Slide Bars Added) NAC International 3.-3

165 "NAC PROPRIETARY INFORMATION" NAC-LWT Cask SAR REMOVED February 2014 Figure 3.-1 Model Detail for the HEUNL Fire and Cool-Down Analysis (with Ribs/Slide Bars Added) NAC International 3.-36

166 "NAC PROPRIETARY INFORMATION" NAC-LWT Cask SAR REMOVED February 2014 Figure Temperature History of HEUNL Liquid in the Hypothetical Fire Event NAC International 3.-37

167 "NAC PROPRIETARY INFORMATION" NAC-LWT Cask SAR REMOVED February 2014 Revision LWT-14 Figure Temperature History of HEUNL Container Shell in the Hypothetical Fire Event NAC International 3.-38

168 NAC-LWT Cask SAR February 2014 Table 3.-1 Maximum Component Temperatures ( F) During the Fire Accident (Design Basis PWR Fuel, 2. kw Heat Load) Component Temperature (ºF) Temperature Limit (ºF) Component O-rings: TFE 8 73 Metallic 71 (3) 800 Cask radial outer surface (1) Neutron shield region (1) Radial lead gamma shield Bottom lead gamma shield Inner stainless steel shell Fuel basket outer wall (2) Fuel rod cladding Alternate Port Cover Bolt head Bolt threads Alternate Port Cover O-ring bore 6 (4) 0 Alternate Port Cover O-ring face 47 0 Alternate B Port Cover metallic face seal Notes: (1) (2) (3) (4) No upper limit established. The loss of the liquid neutron shield is assumed under HAC. The primary consideration in establishing the safe operating range of the aluminum is maintaining the integrity of the aluminum. According to MIL-HDBK-F, it can be shown that aluminum at 700 F retains component performance. The maximum port cover seal temperature is conservatively used to bound the maximum temperature of the metallic seal. Should the bore seal fail post-fire accident, containment would not be breached. NAC International 3.-39

169 NAC-LWT Cask SAR February 2014 Table 3.-2 MTR Fuel Fire Accident Maximum Temperatures ( F), 10 Fuel Plate/120W Element Case (Bounding Configuration) Condition 2: NAC-LWT (Transported via Truck Trailer) Cavity Gas: Air Component Design Basis Heat Loading * Variable Decay Heat Loading ** Cask Radial Outer Surface *** *** Lead Shield *** *** Inner Shell Fuel Basket Fuel Cladding * Uniform 30-Watt/Element Configuration Heat Load. ** 120-Watt/70-Watt/20-Watt Configuration Heat Load. *** The maximum temperatures for these components are bounded by the design basis reported. Table 3.-3 TRIGA Fuel Fire Accident Maximum Temperatures ( F) Component Temperature Fuel Basket 374 Fuel Cladding 433 NAC International 3.-40

170 NAC-LWT Cask SAR February 2014 Table 3.-4 PWR and BWR High Burnup Fuel Rods Fire Accident Maximum Temperatures ( F) NAC-LWT (Transported via Truck Trailer) Cavity Gas: Air Component Component Temperature (ºF) Temperature Limit (ºF) Stainless steel Can Weldment Fuel Rod Cladding 1,014 1, The maximum allowable temperature under HAC for PWR, BWR and PWR MOX fuel rod cladding is 1,08ºF per ISG-11, Revision 3. Table 3.- Maximum Component Temperatures for High Burnup Fuel Rods in a Rod Holder with Damaged Fuel Rods for the Fire Accident Component Normal Conditions Temperature 1 (T norm )(ºF) Temperature Difference (ΔT) (ºF) Accident Temperature T acc = T norm + ΔT(ºF) Rod Holder Weldment = Fuel Cladding = Table Table Table Table Table Table , Condition 2 NAC International 3.-41

171 NAC-LWT Cask SAR February 2014 Table 3.-6 TPBAR Fire Accident Maximum Temperatures Component Temperature ( F) TPBARs 402 Aluminum Basket 340 Consolidation Canister 37 NAC International 3.-42

172 NAC-LWT Cask SAR December 2012 Revision LWT-12E 4.2 Containment Requirements for Normal Conditions of Transport The NAC-LWT cask must maintain a radioactivity release rate less than 10-6 A 2 /hr under normal conditions of transport, as required by 10 CFR 71.1 and IAEA Transportation Safety Standards (SSR-6). The maintaining of a leaktight containment for the NAC-LWT cask, per ANSI N , satisfies this condition. ANSI N specifies and defines a reference (air at standard conditions) leakage rate of ref.cm 3 /s as leaktight. The equivalent allowable helium leakage rate at reference conditions is cm 3 /s (helium), with a minimum helium leak test sensitivity of cm 3 /s (helium). For the transport of TPBAR contents, a leaktight containment boundary provided by metal containment seals is required. Therefore, for the transport of TPBARs under the package designation of USA/922/B(M)-96, Alternate B port covers with metal seals are required to be installed. The structural and thermal evaluations of the NAC-LWT are provided in Chapters 2 and 3, respectively. Results of these evaluations demonstrate that cask containment is maintained as leaktight during normal conditions of transport and hypothetical accident conditions. Therefore, the package satisfies the containment requirements of 10 CFR Containment of Radioactive Material The 10 CFR 71 limit for the release of radioactive material under normal conditions of transport of 10-6 A 2 /hr is assured by the maintenance of a leaktight containment boundary in accordance with ANSI N Pressurization of Containment Vessel The maximum pressure in the cask during normal conditions of transport for other than TPBAR and HEUNL content payloads is calculated by using the methodology presented in Section Assumptions underlying the calculations for contents other than TPBAR and HEUNL are that during normal conditions of transport, 3% of the fuel rods may fail and that 30% of the fission gases in the rods are releasable. The free volumes and resulting pressures are tabulated in Table In addition, for LWR high burnup rods, 6% of the rods with oxide layers greater than 70 micrometers (14 rods) are assumed to fail during transport. This is conservative since fuel rods classified as damaged may have released fission and charge gases prior to transport. Failed rods 4.2-1

173 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 are assumed to have released the fission gas prior to transport. The cask cavity is backfilled to 1 atm with 99.9% pure helium gas. The gas volume (e.g., plenum and pellet to cladding gap) inside the fuel rods is conservatively neglected when calculating the cask free volume. The maximum normal operating pressure (MNOP) of the cavity for the PWR fuel configuration is 1.99 atm. The maximum normal condition cavity pressure for the 2 intact PWR/BWR high burnup fuel rod contents is 2.1 atm. The maximum normal condition cavity pressure with a 6% fuel rod failure rate is 3.2 atm for the 2 BWR high burnup rods and 3.0 atm for the 2 PWR high burnup rods. Pressure evaluations in Section demonstrate that the MNOP is less than 0 psig for aluminum-based nuclear fuels. MNOP for the transport of up to 300 production TPBARs (including up to 2 prefailed rods) is conservatively determined in Section as 289 psig. The TPBAR normal condition pressure assumed clad failure of all 300 TPBARs during transport. The pressure for the TPBAR content condition of segmented TPBARs contained in a waste container and 2 TPBARs contained in a PWR/BWR Rod Transport Canister is bounded by the 300 TPBAR MNOP

174 NAC-LWT Cask SAR February Containment Criteria The standard leak rate for NAC-LWT transports of ref.cm 3 /sec represents the maximum leak rate allowed if the seals were to be tested with air at an upstream pressure of 1 atm and a downstream pressure of 0.01 atm at a temperature of 2 C. This is the maximum allowable leak rate for the containment system fabrication verification, periodic and maintenance leak tests described in Section 4.1 and in Chapter 8. The NAC-LWT leaktight containment criteria, per ANSI N , is ref cm 3 /s, which is equivalent to a helium leak rate of less than, or equal to, std cm 3 /sec (helium) under test conditions. The minimum test sensitivity is cm 3 /s (helium)

175 NAC-LWT Cask SAR February 2014 Table Containment Analysis Basis Cask Free Volumes and Pressures Pressure (atm) Temperature Free Volume Fuel Type Normal Accident (K) (10 cm 3 ) PWR BWR Metallic Fuel TRIGA GA IFM N/A 6 N/A PWR Rods % Failed Fuel Fraction 2 BWR Rods 6% Failed Fuel Fraction Based on Sections and 3..4, the maximum calculated pressures for the PWR payload are 1.93 atm (28.3 psia) normal condition and 8.6 atm (12.8 psia) accident conditions. 2 The maximum pressure for the PWR fuel is conservative. 3 The temperature employed is approximately 4K lower than the maximum fuel clad temperature calculated. The fuel clad temperature is significantly higher than the average gas temperature in the cask. 4 The normal condition temperature is conservatively applied to the 2 PWR and BWR high burnup rod analysis. These pressures result from the 100% fuel rod failure plus the design basis fire accident. 6 Based on the lower temperature and larger free volume of the GA IFM, as compared to the other contents, the pressure, although not explicitly calculated, is lower than that calculated for PWR and BWR fuel. 7 TRIGA volume and pressure conservatively applied to TRIGA cluster rod analysis. Free volume is higher in the cluster rod configuration. NAC International 4.2-4

176 NAC-LWT Cask SAR April 2010 Revision 41 Combining the permeation equations with an activity density of 0.16 Ci/cc, resulting from the release of Ci per event failed rod and moles of tritiated water for each prefailed rods, and T = 72K Maximum accident temperature for the seals per Table 3.-1 o = [LLNL Report UCRL-3441] (stainless steel port seal), [Fusion Science and Technology] (inconel lid seal) E /R = 7,700 (stainless steel port seal), 7490 [Fusion Science and Technology] (inconel lid seal) l = inch for the port cover seal (only considering the stainless steel portion of the seal) and inch for the lid seal P p = 0.1 atm tritium partial pressure in the cask cavity based on the cask free volume, accident condition temperature, and a release of Ci of tritium per event failed rod (conservative modeled as isotope not molecular tritium) and moles of tritiated water from the prefailed rods) yields an approximate release through seal permeation of Ci/week compared to the allowable accident release rate of Ci/week (1A 2 /week based on an A 2 value for tritium of Ci). Actual permeation release rates would be significantly lower as the accident temperatures are short term, with elevated temperatures at the seal locations returning to normal condition temperatures within an hour of the fire. Similar calculations are performed for the equivalent TPBARs, in segments and debris, which may release up to 100% of the tritium contained in the pellets during transport. The pellet tritium content represents approximately 40% of the tritium quantity in the TPBAR. At NAC- LWT normal and accident conditions temperatures, the TPBAR components release tritium primarily as tritiated water with only a small fraction (maximum 2%) as gaseous tritium (see Appendix 1-B of Chapter 1). Gaseous tritium represents the basis for the seal permeation evaluation. During a one-year transport, an additional maximum 1% of the tritiated water may undergo radiolysis and dissociate. Conservatively applying a maximum 3% release rate to the equivalent TPBAR total inventory of 66 grams (1.2 grams per rod) yields an inventory of 0.33 moles T 2. Seal permeation rates based on the conservative temperatures discussed in the previous paragraphs and a 3% tritium gas release are Ci/hr, normal conditions, and 1.06 Ci/week, accident conditions. A gaseous release of over 90% of the 1.2 grams per rod tritium inventory is required to exceed normal condition allowables at the conservative seal temperature of 222ºF. A 100% gaseous release and resulting tritium permeation through the cask seals meets accident condition limits. Reducing seal temperatures less than ºF, to account for a significantly lower decay heat payload (0.127 kw for the waste container TPBARs versus 1.0 kw on which the 222ºF NAC International 4.3-3

177 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 temperature is based), permits a normal condition release of 100% of the tritium in gaseous form while meeting the 10-6 A 2 /hr allowable HEUNL Containment Tritium Contamination Issues Precautions will be taken to minimize the risk of excessive contamination of NAC-LWT casks during the loading and unloading of TPBAR contents to ensure the reusability of the NAC-LWT casks for transport of non-tpbar contents. In addition to ensuring the safe handling of TPBAR contents, additional cavity gas and internal and external removable contamination surveys for tritium contamination will be implemented at all TPBAR loading and unloading facilities. The specific monitoring methods and levels of contamination to which the cask surfaces must be decontaminated are defined in the TPBAR loading and unloading procedures in Chapter 7. In addition, the TPBAR procedures also include precautions for users to observe when loading, unloading and handling TPBARs. The procedures and precautions comply with the recommended practices of NUREG-1609, Supplement 2. The results of previous loading and unloading experiences regarding the measurement of tritium gas and contamination levels are provided in the PNNL letter in Section 1., Appendix 1-G of this SAR. NAC-LWT cask units used for TPBAR transports shall comply with the specified contamination levels, or other non-tpbar users will be advised to incorporate tritium monitoring requirements into their survey procedures and radiological control program. NAC International 4.3-4

178 NAC-LWT Cask SAR April 2010 Revision Containment Analysis of ANSTO Basket Payloads and ANSTO-DIDO Payloads Payloads evaluated in the ANSTO basket are spiral fuel assemblies similar in design to the DIDO assemblies discussed in Section 4..7, and MOATA plate bundles similar in design to MTR assemblies discussed in Section 4... The ANSTO basket is a slightly modified version of the DIDO basket, with each basket containing seven fuel tubes designed to hold one fuel assembly or plate bundle in each fuel tube. Parameter DIDO Basket ANSTO Basket Fuel Assembly Openings 7 7 Fuel Tube OD (inch) Fuel Tube Wall Thickness (inch) The DIDO basket contains aluminum heat transfer components, while the ANSTO basket contains additional support disks. Overall, there are no significant free volume differences between the empty cask assembly configurations. MOATA plate bundles, while displacing more free volume than DIDO assemblies, are limited to maximum burnups of 30,000 MWd/MTU and a minimum cool time of 10 years, resulting in source terms a small fraction of the DIDO payloads evaluated in Section MOATA plate bundles, therefore, do not represent a containment-limiting payload configuration. Spiral fuel assemblies are limited to the cool time curve of the 18-watt MEU DIDO fuel assemblies. As demonstrated in Chapter, Section.3.1, this produces a significantly lower source for the spiral fuel than the 18-watt DIDO assembly. The lower source for the spiral fuel is attributed to a higher fissile material mass in the DIDO evaluation (190 g 23 U versus 160 g 23 U for the spiral fuel), at identical cool time and a maximum depletion of 70%, in conjunction with a lower DIDO enrichment (40 % 23 U for the MEU DIDO fuel versus 7% 23 U enrichment in the spiral fuel calculations). For containment evaluations, the higher heat load, 2-watt DIDO configuration was evaluated, providing additional margin for the spiral fuel assemblies. When compared to the DIDO payload, the spiral assembly payload, therefore, has a significantly lower source of radionuclides at a similar cask free volume. As a result, the DIDO fuel assembly containment evaluation bounds the spiral fuel. As the DIDO containment evaluations bound ANSTO spiral and MOATA payloads, the DIDO evaluations also bound combined payloads. DFCs in seven out of a maximum 42 tubes do not displace a significant cask-free volume (~2%) and, therefore, do not affect the conclusion that the DIDO evaluation is bounding. NAC International 4.-41

179 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February Pressure and Flammability Evaluation of HEUNL Container During transport operations of the HEUNL, solution gas generation and the resulting pressurization of the container must be considered. Also to be considered is a limitation of hydrogen gas volume fraction Pressurization No significant gas generations will occur from the container as a result of galvanic or chemical reactions of the low carbon stainless steel transport container with its contents. A container of stainless steel at less than 0.03 wt% carbon is compatible with the solution and has been used as the solution storage vessel for over 20 years. areas, and potential variations of carbon w The maximum pressure is obtained from the normal-hot transport condition because the liquid volume expansion from the temperature point where it has minimum volume to hot is slightly larger than that from its temperature point where it has minimum volume to cold. Also, the vapor pressure, backfill and generated gas pressures are all directly proportional to temperature changes and are significantly higher at the hot condition than the cold condition. Fire accident conditions increase container temperature and increase the maximum container pressure to 10 psia. No boiling occurs within the container under any operating condition. NAC International 4.-42

180 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February Flammability Hydrogen flammability is addressed both with data available on the solution and in the context of G-value based generation (no credit for test data indicating equilibrium or maximum hydrogen generation). NAC International 4.-43

181

182 NAC-LWT Cask SAR February Discussion and Results The NAC-LWT cask is designed for the safe transport of spent nuclear fuel from various commercial nuclear installations and research reactors..1.1 NAC-LWT Contents The following contents constitute the design basis for transport in the NAC-LWT cask: 1 PWR assembly; up to 2 BWR assemblies; up to 1 sound metallic fuel rods; up to 9 failed metallic fuel rods; up to 3 severely failed metallic fuel rods in filters; up to 42 MTR fuel elements; up to 42 DIDO fuel assemblies; up to 2 PWR fuel rods (including up to 14 rods classified as damaged); up to 2 BWR fuel rods (including up to 14 rods classified as damaged) 1 ; up to 2 PWR or BWR UO 2 fueled high burnup (up to 80,000 MWd/MTU) rods up to 16 PWR MOX or UO 2 rods in any combination (up to 62,00 MWd/MTHM) up to 140 TRIGA fuel elements; up to 60 TRIGA fuel cluster rods; 2 GA IFM packages; up to 300 TPBARs (of which two can be prefailed) in a consolidation canister; up to 2 TPBARs (of which two can be prefailed) in a rod holder; up to TPBARs segmented during PIE, including segmentation debris; up to 700 PULSTAR fuel elements (intact or damaged); up to 42 spiral fuel assemblies; up to 42 MOATA plate bundles; any combination of individual ANSTO basket modules containing either spiral fuel assemblies or MOATA plate bundles up to a total of 42 assemblies/bundles; up to 4,000 lbs of solid, irradiated and contaminated hardware; or 4 HEUNL containers (full, partially filled or empty). 1 PWR and BWR fuel rods may be transported in either a fuel assembly lattice (skeleton) or in a fuel rod insert. The fuel rod insert may contain PWR instrument/guide tubes and BWR water/inert rods in addition to the fuel rods. NAC International.1.1-1

183 NAC-LWT Cask SAR April 2010 Revision 41 The 2 high burnup PWR and BWR rods may be transported in three configurations: 1) a maximum of 2 intact fuel rods loaded in the rod holder; 2) a maximum of 2 fuel rods with up to 14 damaged fuel rods or rod fragments loaded in the rod holder; and 3) a maximum of 2 intact fuel rods housed in a fuel assembly lattice within the NAC-LWT PWR basket. The fuel assembly lattice may be irradiated up to an equivalent burnup of 80,000 MWd/MTU. The metallic fuel consists of a single rod of uranium metal clad with aluminum. The intact metallic fuel rods are placed into a transport canister that will hold five intact rods. The cask can hold three transport canisters for a total of 1 intact metallic fuel rods. In the event the metallic fuel has failed or is suspected of having failed, each fuel rod is sealed in its own container. The failed metallic fuel is loaded into either one of the three holes in the metallic fuel basket or into one of the six openings in the failed metallic fuel basket. MTR research reactor fuel elements are typically 33 to 7 inches long, including lower nozzle and upper handle. The fuel plates typically consist of U-Al, U 3 O 8 -Al, or USi-Al clad with aluminum. The fuel plates are held in a parallel arrangement with two thick aluminum slotted pieces to form a fuel element. Standard fuel elements have between 10 and 23 fuel plates. The active fuel region is typically 22.7 inches in height, and the fuel meat is typically inch thick. The highly enriched uranium (HEU) fuel has been analyzed conservatively with an enrichment of 90 wt % 23 U and fuel loading per element up to 380 g 23 U, with a separate analysis performed to accommodate up to 460 g 23 U. The design basis fuel parameters are provided in Table The fuel characteristics are presented in Table The dose rates produced from the design basis 470 g 23 U and 640 g 23 U LEU and 380 g 23 U MEU MTR fuel are bounded by the HEU MTR design basis fuel. Therefore, a mixed loading of LEU, MEU and HEU MTR fuel elements are also bounded by a full HEU MTR fuel element loading. The source term characteristics of the design basis PWR fuel assembly, BWR fuel assembly, metallic rods, 2 PWR rods, 16 PWR MOX rods, and MTR fuels are given in Table The design basis PWR and BWR fuels require two years of cooling after discharge to meet the neutron and gamma source, and decay heat limits of the cask. The MOX rods require 90 days of cooling. The design basis metallic fuel requires one year cooling. The design basis MTR fuel requires a variable number of years cooling, after discharge, to meet the decay heat limits of the cask. Loading configurations must conform to the limits stated in Section DIDO research reactor fuel elements typically consist of U-Al, U 3 O 8 -Al, or U 3 Si 2 -Al that is aluminum clad. The fuel elements are held in a concentric arrangement inside an outer aluminum cylinder to form a fuel assembly. Fuel assemblies have 4 fuel elements. The active fuel region is typically 23.6 inches in height, and the fuel meat is typically inch thick. The NAC International.1.1-2

184 NAC-LWT Cask SAR December 2012 Revision LWT-12E List of Figures (continued) Figure PICTURE Representation of NAC-LWT TRIGA Payload Fully Loaded Basket Analysis and Mixed TRIGA Loading Figure PICTURE Representation of NAC-LWT TRIGA Payload Reduced Number of Elements in High Fissile Material Element Basket Top and Bottom Baskets Figure Sample Input File for High Mass HEU TRIGA Analysis 3 Intact Elements of 17 g 23 U at 9 wt % 23 U per Basket Opening in Top and Bottom Basket Accident Array Calculation with 8 Casks Figure Sample Input File for High Mass HEU TRIGA Analysis 2 Damaged Elements of 17 g 23 U at 9 wt % 23 U per Basket Opening in Top and Bottom Basket Accident Array Calculation with 8 Casks Figure HEU Cluster Rod Reactivity versus H/Zr Ratio Accident Condition Cask Array Figure LEU Cluster Rod Reactivity versus H/Zr Ratio Accident Condition Cask Array Figure HEU TRIGA Cluster Rod System Reactivity versus Cask Cavity Moderator Figure MEU TRIGA Cluster Rod System Reactivity versus Cask Cavity Moderator Figure TRIGA Cluster Rod Reactivity versus Damaged Fuel Can Moderator (Pref Flood Dry Cask Cavity) Figure PICTURE Schematic of Modified PULSTAR Fuel Assembly Alignment Configuration Figure PULSTAR Intact Assembly Model Moderator Density Study Graphical Results Figure Spiral Fuel Moderator Density Plot Figure MOATA Plate Bundle Moderator Density Plot Figure KENO-Va Validation 27 Group Library Results: Frequency Distribution of k eff Values Figure KENO-Va Validation 27-Group Library Results: k eff versus Enrichment Figure KENO-Va Validation 27-Group Library Results: k eff versus Rod Pitch Figure KENO-Va Validation 27-Group Library Results: k eff versus H/U Volume Ratio Figure KENO-Va Validation 27-Group Library Results: k eff versus Average Group of Fission Figure K eff versus Fuel Enrichment (MCNP - Highly Enriched Uranyl Nitrates) Figure K eff versus Energy of Average Neutron Lethargy Causing Fission (MCNP - Highly Enriched Uranyl Nitrates) Figure MCNP Highly Enriched Uranyl Nitrates USLSTATS Output for EALCF NAC International 6-v

185 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 List of Figures (continued) Figure MCNP Model Sketch of the NAC-LWT Cask with PWR MOX/UO 2 Rods Figure VISED Sketch of LWT Radial View Hex Rod Array Normal Conditions Figure VISED Sketch of LWT Radial View Square Rod Pitch - Accident Conditions Figure VISED Sketch of LWT Axial View Accident Conditions Figure PWR MOX Rod Shipment Reactivity versus Rod Pitch Figure Moderator Density Study UO 2 Fuel Material 3.0 cm Rod Pitch Figure Moderator Density Study MS Fuel Material 3.6 cm Rod Pitch Figure Moderator Density Study PWR MOX 241 Pu Fuel Material 3.6 cm Rod Pitch Figure VISED X-Z Cross-Section of NAC-LWT with HEUNL Figure VISED X-Z Cross-Section of HEUNL Container Detail Figure VISED X-Y Cross-Section of NAC-LWT with HEUNL Figure Axial Sketch of NAC-LWT with HEUNL Figure Radial Sketch of NAC-LWT with HEUNL Figure Axial Sketch of HEUNL Container Figure Reactivity Results by HEUNL H/U Ratio Figure Reactivity Results by HEUNL H/U Ratio Figure VISED X-Z Cross-Section of HEUNL with Alternating Shift Figure VISED X-Z Cross-Section of HEUNL with Inward Shift Figure Cask Cavity Moderator Study Reactivity Results for HEUNL Figure LEU USLSTATS Output for EALCF Figure k eff versus Fuel Enrichment (LEU) Figure k eff versus Rod Pitch (LEU) Figure k eff versus Fuel Pellet Diameter (LEU) Figure k eff versus Fuel Rod Outside Diameter (LEU) Figure k eff versus Hydrogen/ 23 U Atom Ratio (LEU) Figure k eff versus Soluble Boron Concentration (LEU) Figure k eff versus Cluster Gap Thickness (LEU) Figure k eff versus 10 B Plate Loading (LEU) Figure k eff versus Energy of Average Neutron Lethargy Causing Fission (LEU) Figure PWR MOX USLSTATS Output for Water to Fuel Volume Ratio Figure Adjusted k eff vs. Energy of Average Neutron Lethargy Causing Fission Figure Adjusted k eff vs. 23 U/ 238 U Ratio Figure Adjusted k eff vs. 238 Pu/ 238 U Ratio Figure Adjusted k eff vs. 239 Pu/ 238 U Ratio Figure Adjusted k eff vs. 240 Pu/ 238 U Ratio Figure Adjusted k eff vs. 241 Pu/ 238 U Ratio NAC International 6-vi

186 NAC-LWT Cask SAR February 2014 List of Tables (continued) Table DIDO/ANSTO Mixed Payload Analysis Results Table DIDO/ANSTO Basket Plate Separation Evaluation Table DIDO/ANSTO Basket DFC Addition Table DIDO/ANSTO Basket Preferential Flood Analysis Table DIDO/ANSTO Basket Cask Cavity Moderator Density Study Table DIDO/ANSTO Basket Segmented Plate Study Table KENO-Va and 27-Group Library Validation Statistics Table Criticality Results for High Enrichment Uranium Systems Table Highly Enriched Uranyl Nitrates Benchmark K eff s and Uncertainties Table MCNP Criticality Results Highly Enriched Uranyl Nitrates Benchmarks Table Range of Parameters and Correlation Coefficients for Highly Enriched Uranyl Nitrates Benchmarks Table MCNP Highly Enriched Uranyl Nitrates USLSTATS Generated Table USLs for Benchmark Experiments MCNP Highly Enriched Uranyl Nitrates Area of Applicability for Benchmark Experiments Table Highly Enriched Uranyl Nitrates Validated Cross-Section Libraries Table PWR MOX Fuel Analysis Compositions and Number Densities Table PWR MOX Fuel Analysis Isotope Weight Fraction Table PWR MOX Rod Shipment Reactivity as a Function of Geometry and Material Table PWR MOX Fuel Shipment Fuel Rod Pitch Study Table Table Table Table Table Table PWR MOX Fuel Shipment Optimum Moderator Study Maximum Reactivity Summary PWR MOX Fuel Shipment Reactivity Summary for Single Cask Containment Fully Reflected Cases PWR MOX Fuel Shipment Reactivity Summary for Normal Condition Array Cases PWR MOX Fuel Shipments Summary of Maximum Reactivity Configurations PWR MOX Fuel Shipments PWR MOX Comparison to Area of Applicability PWR MOX Fuel Shipments UO 2 Comparison to Area of Applicability Table Bounding Parameters for PWR MOX/UO 2 Rod Shipments Table B&W, CE and Westinghouse PWR Fuel Assembly Data Table Exxon/ANF PWR Fuel Assembly Data Table Composition of HEUNL Solution Table HEUNL Evaluated Model Composition Table HEUNL Actinide Concentration Table Evaluated HEUNL Isotopic Composition Table Evaluated HEUNL Properties NAC International 6-xv

187 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 List of Tables (continued) Table HEUNL Container Design Parameters Table HEUNL Analysis Compositions and Number Densities Table HEUNL Scoping Reactivity Results Table Sample HEUNL Isotopic Composition for Uranyl Nitrate Water Mixture Table HEUNL Reactivity Results for of Uranyl Nitrate Water Mixture Table HEUNL Reactivity Results for of Uranyl Nitrate Table HEUNL Reactivity Results for Fissile Material Shift Study Table HEUNL Reactivity Results for Cask Cavity Moderator Study Table HEUNL Reactivity Results for Container Tolerance Study Table HEUNL Reactivity Results for Mercury Removal Table HEUNL Maximum Reactivity per 10 CFR Table HEUNL Maximum Reactivity per 10 CFR Table Validation Area of Applicability Comparison with HEUNL Results Table HEUNL Reactivity Comparisons for Design Modification and Reflector Dimension Change Table HEUNL Evaluated Libraries Table Evaluated HEUNL Properties for Increased Enrichment Table HEUNL Maximum Reactivity per 10 CFR 71. for Increased Enrichment Table HEUNL Maximum Reactivity per 10 CFR 71.9 for Increased Enrichment Table LEU Range of Applicability for Complete Set of 186 Benchmark Experiments Table LEU Correlation Coefficients and USLs for Benchmark Experiments Table LEU MCNP Validation Statistics Table PWR MOX Range of Applicability for Complete Set of 9 Benchmark Experiments Table PWR MOX Correlation Coefficients and USLs for Benchmark Experiments Table MCNP Validation Statistics NAC International 6-xvi

188 NAC-LWT Cask SAR February 2014 fuel rods (i.e., no gross fuel failure, hairline cracks or pinholes are allowed). All evaluation detail, including input, method, analysis results and critical benchmarks, are included in Section Included are the fuel rod geometry and material description, the MCNP model used in the rod holder analyses, and the criticality analysis results of the NAC-LWT loaded with up to 16 PWR rods (fueled with either UO 2 or MOX material). The system reactivity of the NAC-LWT with up to 16 undamged PWR rods is evaluated as a function of rod pitch. The fuel is assumed to be fresh, i.e., no burnup credit. An infinite array of casks is analyzed. Variation of moderator density inside and outside the cask is considered. Also included in the analysis are preferential flooding evaluations of the canister that contains the rod array. The results show that the bias adjusted k eff of an infinite array of NAC-LWT casks at optimum fuel rod pitch and at optimum interspersed moderation is significantly below the upper safety limit (USL) for MOX and UO 2 critical benchmarks. Analyses are performed on the NAC-LWT with five DIDO baskets containing DIDO elements and an ANSTO top basket module containing DIDO or ANSTO fuel elements. ANSTO basket contents have been evaluated with an aluminum damaged fuel can (DFC). Section presents the methods (CSAS2) and KENO-VA models used in the analysis. Section presents the criticality analysis results of the NAC-LWT cask loaded with the combined payload. Criticality of the NAC-LWT cask with the most limiting fuel characteristics and basket configuration is evaluated. The fuel elements are assumed to be unburned. An infinite array of casks in both the radial and axial extent is analyzed. The results of the analysis show that the bias adjusted k eff of an infinite array of NAC-LWT casks with the most-limiting DIDO/ANSTO basket payload under normal and accident conditions at optimum interspersed moderation (void) is below 0.9. Analyses are performed on the NAC-LWT with 4 HEUNL containers. The HEUNL material is permitted with up to 7.40 g/l 23 U at a maximum 23 U enrichment of 93.4 wt%. The evaluated payload considers a bounding container volume of 64.3 L (17.0 gal). All evaluation detail, including input, method, and analysis results are included in Section The criticality benchmark for this material is provided in Section Criticality of the NAC-LWT cask with the most reactive configuration is evaluated. Considered in the most reactive configuration is the uranyl nitrate (other nitrates separated) at optimal H/U. The results show that the bias adjusted k eff of an infinite array of NAC-LWT casks with the most reactive HEUNL configuration under normal and accident conditions is below the upper safety limit (USL) for highly enriched uranyl nitrates. NAC International 6.1-

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190 NAC-LWT Cask SAR April 2010 Revision 41 themselves and results in the minimum height model (6 cm) being bounding. Differences in reactivity for both sets of cases (k eff ) are taken from the 6 cm active fuel height shifted model. Sets C, D and E As shown in the Set B evaluation, the maximum bias adjusted reactivity of the NAC-LWT with the MTR containing 20 g 23 U per plate is significantly above the 0.9 limit. Set C, therefore, performs a fissile material study to determine the maximum amount of 23 U that may be placed in each plate. To remain below a k s of 0.9, the plates are limited to 18 g 23 U each. Evaluating the fuel at a lower enrichment (0 wt % 23 U) shows that the HEU (94 wt% 23 U) is bounding. To demonstrate that a lower number of plates in the cask is less reactive at the 18g 23 U limit, Set D evaluates a reduced number of plates at maximum (optimal) pitch. Reactivity for these cases is significantly lower than that of the 23-plate case. Set E evaluates various perturbations to the input parameters of the model to demonstrate that the given input is bounding. As shown, there is no significant impact of uranium weight percent changes, modeling an aluminum extension to the width of the fuel plate, or shifting of the aluminum side plates within the plane of the basket. Reactivity decreases with a decreasing plate pitch, an extension of the element length by unfueled plate or end fitting, or changes to the plate thickness by either increasing the fuel core material thickness or the clad thickness. Reactivity increases by decreasing the element side plate thickness, and decreases significantly when inserting two additional aluminum plates approximating the configuration with a loose fuel plate canister inserted into the model. Differences in reactivity ( k eff ) for set C, D, and E are taken from the 6 cm active fuel height shifted model with 18 g 23 U. Set F Not all MTR fuel plates contain less than 18 g 23 U. The HFBR fuel, in particular, contains up to 19. g 23 U per plate but is limited to 18 fuel plates. An analysis is therefore performed with a bounding 19 plate and 20 g 23 U per plate model. The k s for this system is below 0.9. Set G A limited quantity of MTR plates exist with an active fuel width greater than the 6.6 cm evaluated. Therefore, additional analysis is performed at a 7.3 cm active fuel width. Based on the evaluation of an 18 g 23 U per plate model, the reactivity of this system is significantly higher than that of the 6.6 cm width case. Therefore, fissile quantity per plate is restricted to 16. g 23 U. NAC International

191 NAC-LWT Cask SAR April 2010 Revision 41 Set H Low enriched uranium fuel (LEU) can reach a per plate loading up 21 g 23 U. Therefore, evaluations at 7.3 cm and 6.6 cm active fuel width are performed with 23 plates at 22 g of LEU material (maximum 2 wt% 23 U). The 7.3 cm active fuel width resulted in a reactivity higher than the allowed limit. The 22 g 23 U plates of LEU material are, therefore, restricted to a maximum active fuel width of 6.6 cm. Set I NISTR fuel presents an exception to the standard MTR fuel element, since each plate has two fuel sections that are separated by a short section of non fuel-bearing aluminum. These plates may be cut at the aluminum strip, with both sections inserted into a basket opening. This evaluation demonstrates that both an intact and cut element would remain below the licensing limits at 22 grams per plate MTR Fuel Elements with High Fissile Material Loading This section determines the requirements for loading a high fissile material content MTR fuel element with up to 20 g 23 U per plate (460 g 23 U per element based on 23 plates). Section has demonstrated that the HEU fuel is more reactive than LEU and MEU fuel. Therefore, only the HEU fuel is evaluated in this section. Additional evaluations are provided with the limiting characteristics of an HEU MTR element containing up to 21g 23 U per plate. The models employed are similar to those of Section with any differences originating in the modified minimum plate thickness and the amount of axial non-active fuel region material (or spacer material) in the basket. Section relied on a minimum plate thickness of 0.11 cm and a minimum 0.7 cm offset of the active fuel region to the end of the fuel element. The offset of 0.7 cm assured an active fuel region separation of 2.67 cm (2 x 0.7 cm plus the 1.27 cm base plate). Section analyses have shown that increasing the axial separation distance between the fissile material or increasing plate thickness will decrease system reactivity. Both of these effects are taken credit for in the evaluation of the high fissile material loaded MTR element. The minimum plate thickness and element axial end region hardware length are adjusted until k s is below 0.9. Evaluations for various amounts of axial hardware material reveal that with only this change, a minimum 4 cm offset, 8 cm total hardware (spacer material) must be provided for the system reactivity to remain below 0.9 (Table ). Similarly, Table shows that increasing the fuel plate thickness to cm (1.23 mm) is insufficient by itself to reduce reactivity below 0.9. A combination of 2 cm of hardware at the top and bottom of the element, for a total of 4 NAC International

192 NAC-LWT Cask SAR April 2010 Revision 41 Table Baseline MTR Bounding Configurations Parameter (1) Generic NISTR (2) Plate thickness 0.11 cm 0.11 cm Clad thickness 0.02 cm 0.02 cm Number of fuel plates 23 (3) U content per plate 18 g (3,4,) 22 g Enrichment wt % 23 U 94 (4) 94 Active width 6.6 cm () 6.6 cm Active fuel height 6 cm 4 cm Maximum reactivity (k s ) Notes: (1) Loose fuel plates meeting the requirements in this table must be loaded into a MTR plate canister. (2) Fuel plates may be cut in half with each half limited to 11g 23 U and an active fuel length between 27 and 30 cm. (3) (4) () At a 19 fuel plate maximum, the plates are limited to 20g 23 U per plate. LEU fuel plate with up to 22g 23 U may be loaded at a maximum enrichment of 2 wt % 23 U. At a maximum active fuel width of 7.3 cm, the plates are limited to 16.g 23 U. NAC International

193 NAC-LWT Cask SAR April 2010 Revision 41 Table High Fissile Mass MTR Fuel Bounding Parameter Analysis (1) Increased Plate Thickness and Fissile Mass (1) Variation From Baseline (Generic) MTR Increased Plate Thickness and Fissile Mass and Decreased Number of Plates Increased Fissile Mass and Decreased Number of Plates Parameter Plate thickness [cm] Clad thickness [cm] Number of fuel plates U content per plate [g] Enrichment [wt % 23 U] Active Width [cm] Active Fuel Height [cm] Maximum reactivity (k s ) Requires a minimum 4 cm of fuel element hardware (or spacer material) separating the fuel segments axially. NAC International

194 NAC-LWT Cask SAR February MCNP Criticality Benchmarks for Uranyl Nitrates The results of the criticality analyses presented in this chapter must be compared to the upper subcritical limit (USL). The USL accounts for bias and uncertainty resulting from the method using information obtained from the analysis of criticality benchmark experimental data. Code bias calculated in this section is applicable to uranyl nitrates (e.g., HEUNL). Criticality code validation is performed for the Monte Carlo evaluation code and neutron crosssection libraries. Criticality validation is required by the criticality safety standard ANSI/ANS Benchmark Experiments and Applicability Discussion NUREG/CR-6361, Criticality Benchmark Guide for Light-Water-Reactor Fuel in Transportation and Storage Packages, provides a guide to LWR criticality benchmark calculations and the determination of bias and subcritical limits in criticality safety evaluations. In Section 2 of the NUREG, a series of LWR criticality experiments is described in sufficient detail for independent modeling. In Section 3, the criticality experiments are modeled, and the results (k eff values) are presented. The method utilized in the NUREG is KENO-Va with the 44- group ENDF/B-V cross-section library embedded in SCALE 4.3. In Section 4, a guide for the determination of bias and subcritical safety limits is provided based on ANSI/ANS-8.1 and statistical analysis of the trending in the bias. Finally, guidelines for experiment selection and applicability are presented in Section. The approach outlined in Section 4 of the NUREG is described in detail herein and is implemented for MCNP with continuous energy ENDF/B-VII cross-sections. NUREG/CR-6361 implements ANSI/ANS-8.1 criticality safety criterion as follows. k s k c - k s - k c - k m (Equation 1) where: k s = k c = Calculated allowable maximum multiplication factor, k eff, of the system being evaluated for all normal or credible abnormal conditions or events. Mean k eff that results from a calculation of benchmark criticality experiments using a particular calculation method. If the calculated k eff values for the criticality experiments exhibit a trend with an independent parameter, then k c shall be determined by extrapolation based on best fit to calculated values. Criticality experiments used as benchmarks in computing k c should have physical compositions, configurations and nuclear characteristics (including reflectors) similar to those of the system being evaluated. NAC International

195 NAC-LWT Cask SAR December 2012 Revision LWT-12E k s = allowance for the following: statistical or convergence uncertainties, or both, in computation of k s material and fabrication tolerances geometric or material representations used in computational method k c = margin for uncertainty in k c, which includes allowance for the following: uncertainties in criticality experiments statistical or convergence uncertainties, or both, in computation of k c uncertainties resulting from extrapolation of k c outside range of experimental data uncertainties resulting from limitations in geometrical or material representations used in the computational method k m = arbitrary administrative margin to ensure subcriticality of k s The various uncertainties are combined statistically if they are independent. Correlated uncertainties are combined by addition. Equation 1 can be rewritten as shown. k s 1 - k m - k s - (1 - k c ) - k c (Equation 2) Noting that the definition of the bias is = 1 - k c, Equation 2 can be written as shown. where: k s + k s 1 - km - - (Equation 3) = k c Thus, the maximum allowable value for k eff plus uncertainties in the system being analyzed must be below 1 minus an administrative margin (typically 0.0), which includes the bias and the uncertainty in the bias. This can also be written as shown. where: k s + k s Upper Subcritical Limit (USL) (Equation 4) USL 1 - k m - - (Equation ) This is the USL criterion as described in Section 4 of NUREG/CR Two methods are prescribed for the statistical determination of the USL. The Confidence Band with Administrative Margin (USL-1) approach is implemented here and is referred to generically as USL. A k m = 0.0 and a lower confidence band are specified based on a linear regression of k eff as a function of some system parameter. Subsequent sections contain the list of critical benchmarks employed in the validation of MCNP with its continuous energy neutron cross-section libraries and the processing of the experimental results into the USL. Also included are linear fits of reactivity (k eff ) to each of the system NAC International

196 NAC-LWT Cask SAR February 2014 parameters evaluated. Experiments were chosen to reflect the in-cask fuel geometry and materials as closely as available Highly Enriched Uranyl Nitrates Criticality Benchmarks From the International Handbook of Evaluated Criticality Safety Benchmark Experiments, highly enriched uranyl nitrates are selected as the basis of the MCNP benchmarking. Materials selected were solutions of uranyl nitrate. Experiments were selected for compatibility of materials and geometry with the spent fuel casks. As such, experiments containing significant neutron absorber in the form of plates, rods, or soluble poison are eliminated. Also removed are experiments containing non light water moderator. Further review eliminated experiments if they did not contain a primarily thermal neutron spectrum causing fission. All cases were reviewed on a preparer/checker principle for modeling consistency with the cask models and the choice of code options. Case inputs from the handbook where modified to the ENDF/B-VII library to maintain a consistent set. The validated cross-section libraries are listed in Table For isotopes without an ENDF/B-VII library, the latest and most applicable library set was used (i.e. ENDF/B-VI, ENDF/B-V, etc.). Table lists the benchmark k eff and experimental uncertainty. The NAC calculated MCNP k eff s and Monte Carlo uncertainties are shown in Table Stochastic Monte Carlo error is kept within ±0.3% and each output is checked to assure that the MCNP built-in statistical checks on the results are passed and that all fissile material is sampled. Also included in the table are the combined Monte Carlo and experimental uncertainty and the results of the initial processing of the data indicating the minimum and average bias of each experiment. Scatter plots of k eff versus enrichment and average lethargy of neutrons causing fission are shown in Figure and Figure Included in these scatter plots are linear regression lines with a corresponding correlation coefficient (R 2 ) to statistically indicate any trend or lack thereof. NAC International

197 NAC-LWT Cask SAR December 2012 Revision LWT-12E Table Highly Enriched Uranyl Nitrates Benchmark K eff s and Uncertainties Identification k eff σ wt% 23 U HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± HST ± NAC International

198 NAC-LWT Cask SAR December 2012 Revision LWT-12E Table Range of Parameters and Correlation Coefficients for Highly Enriched Uranyl Nitrates Benchmarks Correlation R 2 R Minimum Maximum wt% 23 U 2.E % 93.22% EALCF (ev) 1.74E E-02.26E-01 Table MCNP Highly Enriched Uranyl Nitrates USLSTATS Generated USLs for Benchmark Experiments Variable EALCF File Name ealcf.out # Points 106 AOA Range ev X ev Administrative Margin 0.0 USL Table MCNP Highly Enriched Uranyl Nitrates Area of Applicability for Benchmark Experiments Fissile Form Nitrate Solutions Geometry Spheres, Rods (Cylinders) Moderator Light Water, Tap Water, or None H/U Ratio to 200 EALCF (ev) 3.06E-02 to.26e-01 NAC International

199 NAC-LWT Cask SAR February 2014 Table Highly Enriched Uranyl Nitrates Validated Cross-Section Libraries c c c c c c c c c c c c c c c c c 20.0c c c c c c c c c c c c lwtr.10t c c c c c c c c c c c c c c c c c c c c NAC International

200 NAC-LWT Cask SAR February HEUNL This section includes input, analysis method, and results for the NAC-LWT cask containing a payload of four HEUNL containers. The transport package is evaluated in compliance with 10 CFR 71.9 and 10 CFR 71.. The evaluation considers an H/U study, shift study, moderator study, and container tolerance study Package Fuel Loading Four HEUNL containers may be loaded into the NAC-LWT. The HEUNL material consists of uranyl nitrate, various other nitrates, and water. Composition of the HEUNL material is provided in Table The evaluated nitrate contents are further detailed in Table The HEUNL material density at 2 C is 1.30 g/cc. The actual and modeled actinide concentrations are listed in Table The HEUNL is conservatively modeled by increasing the 23 U partial density to 7.2 g/l. 234 U and 236 U are conservatively modeled as 238 U. 234 U (σ t = 116 b) and 236 U (σ t = 14.1 b) have higher absorption cross-sections than 238 U (σ t = 12.2 b). Removing absorption from the criticality model is conservative. The evaluated 23 U partial density bounds all provided design input for the processed material. Additional analysis is performed for the target material initial enrichment. This additional analysis increases enrichment to 93.4 wt. % at a 23 U partial density of 7.40 g/l. The HEUNL solution contains a negligible amount of 237 Np, 239 Pu, and 240 Pu. These isotopes are less than wt. % of the solution and are therefore excluded from the MCNP model. Removal from the criticality evaluation will have a negligible effect. The evaluated isotopic content for the HEUNL material is listed in Table Critical properties for the HEUNL criticality evaluation are summarized in Table The water content of the solution is calculated using the solution density and nitrate inventory. The calculated water content is approximately 68 wt. %. The criticality analysis includes the uranyl nitrate at various geometries with water intrusion in the material lattice for optimal moderation. For the fissile material geometry study, a bounding container cavity volume of 17.0 gal (64.3 L) is applied. For the initial nominal studies, a standard fill using the modeled container cavity volume is applied. The nominal case is bounded by the optimal fissile material geometry Criticality Model Specifications This section describes the models that are used in the criticality analyses for the NAC-LWT cask containing four HEUNL containers. The models are analyzed separately under normal NAC International

201 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 conditions and hypothetical accident conditions to ensure that all possible configurations are subcritical. Each model uses the MCNP v1.60 code package with the cross-section libraries validated for highly enriched uranyl nitrates (see Section 6..4). No cross-section pre-processing is required prior to MCNP use. MCNP uses the Monte Carlo technique to calculate the k eff of a system. Description of Calculational Models Four HEUNL containers are modeled in the NAC-LWT. The containers and cask are modeled as described in the license drawings. Tube quick disconnect fittings, the bottom portion of the container outer shell that rests on the shoulder and axially overlaps the container and neck, and base plate are conservatively omitted from the shielding model. Removal of stainless steel, an absorption material, is conservative for the criticality evaluation. Containers are shifted towards the top of the cask cavity. Axial location of the containers will have a negligible effect on the criticality evaluation. For all configurations, containers are modeled as touching to increase neutronic coupling. No evaluation of potential separation of containers with moderation is necessary as the optimal H/U ratio is established in the maximum reactivity configuration studies. Increased separation would only increase neutron leakage. flat configuration will have negligible effects on the criticality evaluation as a bounding container cavity volume is applied.. The The criticality evaluation considers both normal and accident conditions. The accident conditions of transport include the loss of neutron shielding material, the neutron shield shell, and the impact limiters. The geometric description of a MCNP model is based on the combinatorial geometry system embedded in the code. In this system, bodies such as cylinders and rectangular parallelepipeds and their logical intersections and unions are used to describe the extent of material zones. Detailed model parameters used in creating the three-dimensional model are derived from the license drawings. Elevations associated with the three-dimensional features are established with respect to the center bottom of the NAC-LWT cask cavity for the MCNP combinatorial model. The three-dimensional NAC-LWT MCNP models are shown in Figure through Figure , while sketches are shown in Figure through Figure Select container dimensions critical to the MCNP model are listed in Table NAC International

202 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Package Regional Densities The composition densities (g/cc) and nuclide number densities (atm/b-cm) evaluated in subsequent criticality analyses are shown in Table Criticality Calculations This section presents the criticality analyses for the NAC-LWT cask with HEUNL containers. Criticality analyses are performed to satisfy the criticality safety requirements of 10 CFR Parts 71. and 71.9, as well as IAEA SSR-6. The maximum reactivity configuration is determined by implementing a series of studies. The series of studies are designed to meet 10 CFR 71. (b) and (e) requirements on normal and accident condition single casks. The single cask analysis by regulation must consider a fully water reflected package and be at optimum physical configuration and moderation. Each study will retain the maximum reactivity configuration from the previous study. After the single cask analysis is complete, cask array analysis is performed to meet 10 CFR 71.9 requirements. Per the standard review plan (NUREG-1617) the 10 CFR 71.9 requirements are met by evaluating a cask array with dry cask interior and cask exterior for normal condition and optimum interior and exterior moderated array for accident conditions (see Sections 6.. and 6..6 in NUREG-1617). As the HEUNL containing cask array is evaluated as an infinite array, the exterior to the array condition is not applicable. 10 CFR 71. Scoping Calculation In compliance with 10 CFR 71. the scoping calculations are based on a single cask with a 20 cm boundary from the cask exterior dimensions. The space between cask and boundary is flooded with full density water to produce a fully water reflected system. Initial scoping analysis evaluates cask interior flooding conditions. Due to the system containing little cavity volume for moderation, flooding conditions have negligible effects on reactivity. Normal and accident configuration casks are expected and are confirmed to be similar from a neutronics perspective. Geometry differences are limited to the presence/absence of the neutron shield. For a fully water reflected cask, differences in neutron tracking between the models are those associated with ethyl glycol/water in the first inches of reflector and Monte Carlo differences for tracking through the additional reflector. NAC International

203 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Table contains a summary of the scoping results. Maximum reactivity is obtained by a void cask interior. Either normal or accident condition cask geometry can be chosen for the following evaluations without a statistically significant difference in result. For this calculation the accident condition cask geometry was chosen. 10 CFR 71. Uranyl Nitrate H/U Study As shown in the scoping analysis, the nominal HEUNL solution k eff is below limits. The nominal HEUNL solution is defined for this criticality evaluation as the loaded solution. The worst case configuration for the HEUNL includes all non-fissile nitrates precipitating out from the solution leaving only a uranyl nitrate-water mixture. NAC International

204 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February CFR 71. Uranyl Nitrate Shift and Cask Cavity Moderator Study NAC International

205 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February CFR 71. Optimum Tolerance Studies Results for the tolerance study are shown in Table The tolerance results show no statistically significant increase for any tolerance. Therefore, tolerances will not be applied in the maximum configuration. MCNP Validated Libraries The MCNP models use the cross-section libraries validated for highly enriched uranyl nitrates (see Section 6..4). The evaluated libraries are listed in Table The ZAID library for lead, c, was not included in the MCNP validation highly enriched uranyl nitrates. Lead is used as a shield material in the NAC-LWT MCNP model. Exterior reflector material validation is not a significant issue for moderated systems where fuel region neutronic interaction, not reflection, is the primary reactivity driver. The ZAID library for mercury, c, was not included in the MCNP validation of highly enriched uranyl nitrates. Mercury is a strong absorber with capture cross section, σ γ, of 376 b. Therefore, mercury is replaced in the MCNP model with aluminum (σ γ = 0.23 b) to account for NAC International

206 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 the lack of validation for mercury. The previously established maximum reactivity configuration is retained for this study. As shown in Table , removal of mercury statistically increases system reactivity. All other evaluated libraries are accounted for in the validation. 10 CFR 71. Maximum Reactivity Summary Based on the previous studies, the following conditions are bounding for the maximum reactivity configuration: Uranyl nitrate water mixture in Uranyl nitrate water mixture optimally moderated Uranyl nitrate mixtures shifted in alternating configuration Dry cask cavity Mercury removed from model Maximum system reactivities are determined with this maximum reactivity configuration under normal (neutron shield present) and accident (no neutron shield) conditions. As seen in Table , the maximum reactivity is and below the USL of CFR 71. (b) (3) requires an evaluation of the NAC-LWT with the containment system fully reflected by water. The containment for the NAC-LWT is the cask inner shell. While no operating condition results in a removal of the cask outer shell and led gamma shield, the most reactive case is re-evaluated by removing the lead and outer shells (including neutron shield), and reflecting the system by water at full density. Using the maximum reactivity configuration, the calculated k eff +2σ is , which is significantly below that of the full cask water reflected model (i.e., neutron reflection produced by the lead gamma shield and outer steel cask shell produces a higher reactivity system than that produced by a water reflector. 10 CFR 71.9 Maximum Reactivity Summary 10 CFR 71.9 (a) (1) requires the evaluation of five times N normal condition packages. 10 CFR 71.9 (a) (2) requires the evaluation of two times N accident condition packages with optimum moderation. Both normal and accident conditions specified by the CFR are satisfied with the maximum reactivity configuration defined for the 10 CFR 71. evaluation. The model is modified by applying a reflecting surface at the cask exterior surface. This option produces an infinite array of casks. As seen in Table , while slightly increasing system reactivity above that of a single cask, both results are below the USL of The resulting CSI for an infinite array of NAC-LWT casks with HEUNL is 0. NAC International

207 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Water Reflector and Canister Dimensions Increased Enrichment Evaluation Previous analyses were based on measured uranium concentrations for the processed material. The analysis in this section applies the maximum initial enrichment of the target material, 93.4 wt. %. The partial density of 23 U is also increased from 7.20 g/l to 7.40 g/l. The modeled H/U ratio is slightly reduced from 47 to 33 for this model due to the changes in 23 U concentration (i.e., the sphere radius is held constant). All H/U ratios for the HEUNL evalautions and the validation in Section 6..4 for uranyl nitrates are in terms of moderator to fissile ratio ( 23 U). The evaluated HEUNL properties for the increased enrichment are provided in Table The 30 cm water reflector and increased container length are retained for this evaluation. Results for the 10 CFR 71. (b) and (e) evaluations are listed in Table Results for the 10 CFR 71.9 (a) evaluations are listed in Table For the 10 CFR 71. (b) (3) evaluation, the reactivity is calculated to be All results remain under the USL of Code Validation and Area of Applicability Critical benchmarks and USL are discussed in detail in Section The following evaluates the applicability of the USL to HEUNL. The area of applicability (AoA) for the validation is compared to the system parameters for the NAC-LWT with HEUNL most reactive case. The USL, , used for this calculation is based on the energy of the average neutron lethargy causing fission (EALCF). Table shows the validated range of EALCF. The USL for the validation is the minimum USL from the EALCF range. The EALCF for the most reactive HEUNL case is 0.04 ev and is within the validation range. NAC International

208 NAC-LWT Cask SAR February 2014 Exceeding the area of applicability for enrichment of the benchmark cases is acceptable as the parameter has a trend that is statistically insignificant (R = 0.0) and the difference outside the range is small (0.18 wt. %) relative to the margin to the USL (> 0.02) Allowable Cask Loading Based on the results of the previous sections, loading of 4 HEUNL containers is allowed in the NAC-LWT. Maximum content of the container is limited to 17 gallons of solution with a maximum 7.40 g 23 U per liter. The transport package has been found to be in compliance with 10 CFR 71.9 and 10 CFR 71.. The maximum reactivity, including two sigma, of for the transport package is subcritical. This evaluation has considered an H/U study, shift study, moderator study, and container tolerance study. The transport package has been designated a CSI of 0. To achieve HEUNL container fill capacity, dilution of the HEUNL container is allowed. NAC International

209 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure VISED X-Z Cross-Section of NAC-LWT with HEUNL Figure VISED X-Z Cross-Section of HEUNL Container Detail NAC International

210 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure VISED X-Y Cross-Section of NAC-LWT with HEUNL NAC International

211 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure Axial Sketch of NAC-LWT with HEUNL NAC International

212 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure Radial Sketch of NAC-LWT with HEUNL Figure Axial Sketch of HEUNL Container NAC International

213 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure Reactivity Results by HEUNL U Ratio Figure Reactivity Results by HEUNL H/U Ratio NAC International

214 NAC PROPRIETARY INFORMATION NAC-LWT Cask SAR REMOVED February 2014 Figure VISED X-Z Cross-Section of HEUNL with Alternating Shift Figure VISED X-Z Cross-Section of HEUNL with Inward Shift Figure Cask Cavity Moderator Study Reactivity Results for HEUNL NAC International