Measure to solve technical subjects in UCS replacement. Experimental Fast Reactor Joyo Oarai R&D Center, JAEA

Transcription

1 1 Measure to solve technical subjects in UCS replacement Experimental Fast Reactor Joyo Oarai R&D Center, JAEA

2 2 Configuration of equipment in UCS replacement

3 6330mm 2710mm 2266mm Structure of UCS GL-3110 : Top of R/P Large rotating plug Small rotating plug S-R/P GL-3130 : Top of UCS φ1160mm φ1130mm 444mm φ1070mm φ1010mm UCS guide Sleeve (GS) UCS GL-6100 (Sodium level during operation) φ1100mm φ1060mm UCS (Weight : ~16.5ton) UCS (during construction) GL-9460 : Bottom of UCS GL-9490 : Top of subassemblies 3

4 Outline of UCS replacement Wire jack-up equipment UCS Screw jack-up equipment Cask Door valve Cask S-R/P L-R/P UCS Temporary pit cover Guide tube Ed-UCS is extracted through small-diameter part. (1) Jack-up of ed-ucs (2) Retrieval of ed-ucs (3) Installation of n-ucs ed-ucs : existing damaged UCS Plant condition : n-ucs : new UCS - Fuel S/As are remained in reactor vessel. >>> Sodium level is maintained at 50 mm below top of fuel S/A. - Temperature of sodium is approximately 200deg-C, and temperature of cover gas is approximately 140~160deg-C. 4

5 Equipment Configuration in ed-ucs jack-up ed-ucs jack-up equipment Adjustment bolt in horizontal Guide pin Temporary pit cover Jack-up ed-ucs to 1000 mm Load measuring device Guide tube Vinyl bag Guide bolt R/P ed-ucs Level measuring device Inflate seal Support Hanging plate Hanging bolt Liner fastening bolt Gap monitoring equipment Fitting area monitoring equipment 5

6 6 Equipment Configuration in ed-ucs retrieval Cask Wire jack equipment Base frame for wire jack equipment Door-valve ed-ucs Retrieve ed-ucs into cask Ed-UCS bottom observation equipment Simplified boundary R/P

7 7 Equipment Configuration in n-ucs installation n-ucs Install n-ucs R/P

8 8 Measure to solve technical subjects in UCS replacement

9 9 Major subjects in UCS replacement (1) Prevention of deformation of ed-ucs and GS (2) Detection of interference and contact between ed-ucs and GS (3) Insurance of cover gas boundary (4) Measure for unexpected incident (Ex. failure of ed-ucs jack-up/pulling-up)

10 Measure to prevent of deformation > To prevent deformation of ed-ucs and GS, allowable load is investigated using Abaqus/Standard Version with 3-D modeling. > To prevent interference and contact between ed-ucs and GS, allowable inclination is investigated. And, to achieve a strict control, following two measures are implemented in the design of jack-up equipment. - Applying three-point suspension - Inclination monitoring with level- and load-measuring devices 10

11 Investigation of allowable load in ed-ucs jack-up and pulling-up Pulling height (mm) Allowable load (t) Resistance 0 ~ Sodium bridge shearing force notes Jack-up speed : <2mm/h *1 2 ~ Sodium bridge shearing force 484 ~ Interference resistance 862 ~ 1.73 Contact resistance *1: Deformation at the point of force application of wringing force (3.37t) is unlikely owing to its thick structure. However, in the case that sodium bridge shearing is incomplete, there may be a risk of guide sleeve deformation due to rapid release of the wringing force. jack-up speed is limited to below 2 mm/h to prevent permanently deforming guide sleeve. To prevent deformation of ed-ucs and guide sleeve with applying above allowable load 11

12 Investigation of allowable load in n-ucs installation Pulling height (mm) Allowable load (t) Resistance ~ ~ ~ Interference resistance (between UCS bottom and GS) Interference resistance (between UCS and GS) Contact resistance (between UCS and GS) UCS bottom reaches top of φ1160mm part of GS UCS bottom reaches top of φ1070mm part of GS Bottom of UCS φ1050mm part reaches top of φ1070mm part of GS Height : 6145mm Height : 4482mm Height : 4104mm 12

13 13 Requirement to jack-up equipment 1. Load regulation system to prevent deformation of ed- UCS and GS Allowable load (Ex. during ed-ucs jack-up) : 0.72t (0~484mm) 1.09t (484~862mm) 1.73t (862mm~) 2. Inclination control and monitoring system to prevent interference and contact between ed-ucs and GS Allowable inclination (Ex. during ed-ucs jack-up) : 0.039deg (0.69mm/m)* * Assuming a conservative 2.5 mm gap

14 Structure of Jack-up equipment (1/2) Screw jack Three screw jacks are located uniformly in a concentric configuration. Vertical Screw jack displacement measuring device Handle Temporary pit cover 1100mm Guide tube Temporary boundary Jack-up equipment Base mechanism of screw jack Servomotor R/P UCS Jack holder base Jack-up equipment is installed on guide tube. Prevent interference and contact between ed-ucs and GS by means of adjusting guide tube location together with jack-up equipment. Load measuring device Hanging plate 吊り蓋 Manual : 0.025mm/rotation Auto : 0.017~1mm/s Level measuring device Required Max. load : ~40t ( total load of three screw jack ) 14

15 15 Structure of Jack-up equipment (2/2) Top of jack-up equipment Connection part of screw jack Screw jack (connection) Hanging plate Load measuring device Level measuring device Hanging bolt Vertical displacement measuring device (in tube) Handle (attachment) Guide tube (Dummy) Guide bolt Reduction gear UCS (Dummy) Servomotor

16 Mock-up test for jack-up equipment To confirm performance of jack-up equipment using mock-up Configuration of mock-up Testing frame Guide tube (Dummy) ~5m ~7m ~9m GS (Dummy) UCS 模擬体 UCS (Dummy) > Dummy UCS can be jacked-up until 1000mm. > Emergency stop system with over-load detection is performed successfully. > Inclination of dummy UCS is ensured below deg. (0.69mm/m) due to strict synchronization of three screw jacks. * Inclination of dummy UCS is almost constant : <0.015deg. (Fluctuation : <0.01deg.) Above achievement are confirmed using dummy UCS with assuming maximum tolerance * Gap between dummy UCS and dummy guide sleeve : 0.65mm in minimum (5mm in nominal design) 16

17 17 Measure to Detection of interference and contact between ed-ucs and GS > Direction method of interference and contact is investigated by means of calculation of off-set direction of center of gravity based on loads of three screw jack. > Adjustment bolts are prepared to adjust guide tube location together with jack-up equipment. > It is confirmed that dummy UCS can be pulled up with adjustment of guide tube location to escape interference and contact in mock-up test.

18 Load (kg) Load (kg) 18 Load behavior in interference and contact (example) 1100 Interference 第 5 回 1200 Contact Load is changed gradually 第 5 回 Load is changed rapidly Pulling height (mm) Pulling height (mm)

19 Load ratio (local load / total load) Development of detection method of interference and contact Z2 Z3 Z1 Location of Interference (Ex.(1)) Z2 Center of gravity(2) Center of gravity(1) Z Ex.(1) : at 0 deg. Ex.(2) : at 210 deg. Z1 Location of Interference (Ex.(2)) Estimated behavior of eccentric load 1. Z1, Z2, Z3 have eccentric load caused by interference and contact 2. Center of gravity based on loads of Z1, Z2, Z3 is moved from (1) to (2). >>> Location of interference and contact is investigated by off-set direction of center of gravity (balance of load ratio) Location of interference (deg.) 19

20 Off-set direction of center of gravity (deg : Test result) Investigation of detection method of interference and contact Configuration of equipment Test result 360 Z :Set point :Test result 180 Dummy plate Z3 120 Z1 Center of gravity(1) Center of gravity(2) 60 0 Off-set direction of center of gravity agrees with direction of interference Direction of interference (deg : set point) - Direction of interference can be investigated by means of calculation of offset direction of center of gravity based on loads of three screw jack. - Ed-UCS can be pulled up by means of adjustment of guide tube location in horizontal using dummy of lower part of UCS with maximum tolerance (gap : 0.65mm in minimum (nominal gap is 5mm)). 20

21 21 Measure to insure cover gas boundary > Because radioactivity in cover gas is quite low due to long time reactor shutdown, prevention of impurities contamination is just required in this work. > Vinyl bag with slight positive pressure is installed as main temporary boundary. > Assuming breakage of vinyl bag, simplified boundary is prepared during period that it is impossible to access to near vinyl bag due to high dose rate. And, in order to prevent impurities contamination, pressure of simplified boundary is kept slight negative. > Reduction of vinyl bag temperature is conducted by means of Ar gas blow in order to secure integrity of vinyl bag

22 Operation procedure of temporary boundary Simplified boundary Ar gas blow down Ar gas 150~200Pa Ar gas supply Protection plate R/P Ar gas <150Pa Vinyl bag Air -50~0Pa > With positive pressure of vinyl bag (simplified boundary : negative), impurities contamination is prevented, assuming breakage of vinyl bag. > In order to secure integrity of vinyl bag, high temperature Ar gas rising is inhibited by means of Ar gas blow of ~100L/min (initial value). Argon blow rate is adjusted as required (thermometer is installed in vinyl bag). > Protection plate is installed in vinyl bag with assuming unexpected negative pressure of vinyl bag in order prevent contact between UCS and vinyl bag. 22

23 23 Ref. Structure of vinyl bag Tap (M8) Vinyl bag Vinyl bag Guide tube Attachment

24 Argon gas blow to secure integrity of vinyl bag Empirical equations concerning with argon gas blow down (1) Re>Gr/3 * Empirical equation applied to argon gas flow rate evaluation for Joyo fuel handling machine (2) Gr/(Re 1.43 Fr 0.35 )<32.5 * Empirical equation to prevent that high temperature argon gas flow into argon gas blow down channel (3) Gr/(Re 1.43 (1/De))<3.74 * Empirical equation to prevent that high temperature argon gas reach at top of argon gas blow down channel Re : Reynolds number Gr : Grashof number Fr : Froude number De : Equivalent diameter Results (1) ~1020 L/min (2) ~106 L/min (3) ~21 L/min Initial flow rate of argon gas blow down : 100L/min * With monitoring using thermometer installed in vinyl bag 24

25 Measure for unexpected incident (Ex. failure of ed-ucs jack-up/pulling-up) - Recovering ed-ucs to initial position (or holding ed-ucs on position at the time) - Discussing measure based on obtained data (stroke, load, inclination, etc.) - Re-jack-up and pulling-up of ed-ucs with discussed measure 1. Beforehand discussion for recovering ed-ucs to initial position (1) Investigation of allowable load In order to prevent deformation of ed-ucs and GS during recovering work, load is regulated below allowable load which is same as ed-ucs jack-up. (2) Training using mock-up Specific boundary equipment for recovering is prepared, then equipment performance and working procedure are confirmed through mock-up test. 2. Preparation of data accumulation system for unexpected failure of ed-ucs jack-up and pulling-up (1) Observation equipment in R/V UCS fitting area visual monitoring equipment etc. are prepared (2) Obtaining detailed data of load and inclination Although jack-up speed is 60mm/min in maximum, in order to obtain data of load and inclination behavior in detail, jack-up speed is regulated 0.33mm/min (2mm/h) in initial state (pulling height : 0 ~ 2mm). (3) Preparation of mock-up for investigation of cause Data of above (2) is analyzed and evaluated using prepared mock-up for investigation of cause. 25