Verification of the LUDEP software

Transcription

1 Verification of the LUDEP software LUDEP is a software package developed by the National Radiological Protection Board, United Kingdom for the calculation of internal doses using the new ICRP Respiratory Tract Model (ICRP Publication 66). However, the latest commercially available version 2.07 still applies the biokinetic models of the ICRP Publications 30 and 54. The software is intended basically for the estimation of internal doses from intakes, however there is a possibility to calculate the retention or excretion function and to estimate the intake based on these functions and the measured in-vivo or invitro data. Consequently, the calculation results of the software depends on a wide set of parameters should be set by the user. It makes the software flexible but complicates its use at the same time. The calculation depend also on internal nuclide and biokinetic model specific parameters and the user can not expect acceptable results for a radionuclide, even if the calculation yielded reasonable values for another nuclide of the same chemical element. The verification of the retention and excretion values was attempted for the radionuclides of ICRP Publication 78, but the calculations were also performed for all relevant radionuclides of ICRP Publication 54 and these results are presented, too. However, it should be emphasized that the last results are only for information and were not used for the verification. According to the ICRP methodology used for internal dose assessments, the verification process consisted of two main steps: 1) comparison of m(t) values calculated by the software with the tabular data of ICRP 78 (or ICRP 54) for the estimation of radionuclide intake from the measured activity results 2) comparison of e(g) inh,j and e(g) ing,j inhalation and ingestion dose factors calculated by the software with the data given in the IAEA Basic Safety Standards. The main parameters applied for the calculation in accordance with the above mentioned ICRP and IBSS publications were the following: 1) AMAD = 5 μm, Type M material (if this assumption was not adequate for the given radionuclide, the most restrictive parameters were chosen) for the inhalation case 2) f 1 values given for unspecified compounds or the most restrictive ones for the ingestion case. The selection of radionuclides for the calculations was based on the recent practice of the IAEA laboratories. The retention and excretion results calculated by LUDEP for the inhalation case are given in Table 1. The abbreviations in the Sample column of the Table are: U urine, WB - whole-body, Th - thyroid and Lu - lungs. The cells with grey colour indicate the values intended only for information and have not be used for verification. As LUDEP needs separate input parameter sets, the Lung Model column indicates the solubility types according to the ICRP Publication No. 66 and the Biokinetic Model column contains the information concerning the biokinetic model according to ICRP Publication No. 30 used for the given calculation. The retention end excretion functions have built in parameter sets based on the ICRP

2 Publication No. 54. For calculations of excretion of Pu/Am radionuclides the ICRP 54 model (D) was used, instead of the Jones model (J) (see the Remark column). Table 2. summarizes the retention and excretion values following 1 Bq acute intake from the Tables of the ICRP Publications No 54 and 78. To keep the same structure the radionuclides with no values are also presented. The meaning of the abbreviations is the same as above. The last column now indicates the ICRP publication where the values were taken from. It should be noted, that there are not tabular values for each radionuclides for the total days time period. The relative differences of the retention or excretion function values calculated by the LUDEP software following a single intake by inhalation at different time are given as the percentages of the tabular values of ICRP Publications No 54 and 78 in Table 3. The abbreviations are the same as above. The relative differences of the inhalation dose factors calculated by the LUDEP are given as the percentages of the tabular values of the IAEA Basic Safety Standards in Table 4. The abbreviations are the same as above. The results of the intercomparison clearly indicate that LUDEP can be used only for a limited number of radionuclides for dose estimation, or for estimation of intake by the help of the calculated retention or excretion curves on routine basis. The detailed evaluation of the results gives the following: - The relative differences of the inhalation dose factors are usually below 10 percent for radionuclides described by relative simple biokinetic models (except of Zr-95 and Ba-140) and are also acceptable for U and Pu isotopes. In some cases the difference is acceptable for one radionuclide but it is very high for the other nuclide of the same chemical element (cf. Ra-226 and Ra-228 or Cm-242 and Cm-244). - The relative differences in the urine excretion function values are much higher. There are only a few radionuclides (H-3, radiocesium, etc.) having acceptable differences in the whole investigated time-period. - The results are obviously much better for the lung retention calculations, where there are no differences practically. - The whole-body and thyroid retention values are also acceptable, generally. There are remarkable differences from the ICRP 54 values, but as we noted already the biokinetic models and parameters used are quite different. The retention and excretion values calculated by LUDEP for the ingestion case are given in Table 5. The cells with grey colour indicate the values intended only for information and cannot be used for the verification. The abbreviations in the last column of the Table are: U urine, WB - whole-body, Th - thyroid and Skel - skeleton. It should be noted, that the retention and excretion functions following a single intake by ingestion are only tabulated until 10 days, treated as a subject of the special monitoring by the ICRP 78. Table 6. summarizes the retention and excretion values following 1 Bq acute intake from the Tables of the ICRP Publication No 78. To keep the same structure the radionuclides with no values are also presented. The meanings of abbreviations used are the same as above.

3 The relative differences of the retention or excretion function values calculated by the LUDEP software following a single intake by ingestion at different time are given as the percentages of the tabular values of ICRP Publications No 78 in Table 7. The abbreviations are the same as above. The ingestion dose factors calculated by LUDEP are summarized in Table 8. The results of the intercomparison are very similar to the inhalation case or even worse. Conclusion: it can be stated, that only the lung retention results calculated by the LUDEP are consistent with the biokinetic data given in the ICRP Publication No 78 for each radionuclide considered and for the whole time-period investigated. The use of the software needs experienced and well educated staff. The evaluation of calculation results concerning dose factors, retention and excretion values (except of the above mentioned lung retention case) can be applied only following a careful case-by-case investigation.

4 Table 1. The retention/excretion values calculated by the LUDEP software following a single intake of 1 Bq for days Inhalation case m(t) Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Lung Biokinetic Model Model Sample Remark H-3 2.2E E E E E E E E E E-08 U A P E E E E E E E E E E-09 M W U B Cr E E E E E E E E E E-04 M W.V WB Cr-51 no data Mn E E E E E E E E E E-02 M W WB Mn-54 no data Fe E E E E E E E E E E-03 M W WB Fe-59 no data Co E E E E E E E E E E-02 M W WB Co E E E E E E E E E E-05 M W U Co E E E E E E E E E E-03 M W WB Co E E E E E E E E E E-06 M W U Co E E E E E E E E E E-02 M W WB Co E E E E E E E E E E-05 M W U Sr E E E E E E E E E E-02 S Y.S WB Sr E E E E E E E E E E-07 S Y.S U Sr E E E E E E E E E E-07 S Y.S U Sr E E E E E E E E E E-06 S Y.S U Zr E E E E E E E E E E-03 M W WB Zr-95 no data Ru E E E E E E E E E E-02 M W WB Ru E E E E E E E E E E-05 M W U A) there is no built in excretion function in LUDEP, calculation for ingestion; B) the c2 parameter is wrong in the excretion function in LUDEP (typing error)

5 Table 1. The retention/excretion values calculated by the LUDEP software following a single intake of 1 Bq for days Inhalation case (Cont.) m(t) Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Lung Model Biokinetic Model Ag-110m 5.0E E E E E E E E E E-02 M W WB Ag-110m no data Sb E E E E E E E E E E-03 M W WB Sb-124 no data Sb E E E E E E E E E E-02 M W WB Sb-125 no data I E E E E E E E E E E-03 F D Th I E E E E E E E E E E-05 F D U I E E E E E E E E E E-02 F D Th I E E E E E E E E E E-04 F D U I E E E E E E E E E E-09 F D Th I E E E E E E E E E E-11 F D U Cs E E E E E E E E E E-01 F D WB Cs E E E E E E E E E E-04 F D U Cs E E E E E E E E E E-01 F D WB Cs E E E E E E E E E E-04 F D U Ce E E E E E E E E E E-03 M W WB Ce E E E E E E E E E E-08 M W U Ce E E E E E E E E E E-02 M W WB Ce E E E E E E E E E E-07 M W U Hg E E E E E E E E E E-03 M W.I WB Hg-203 no data Ra E E E E E E E E E E-02 M W.V WB Ra E E E E E E E E E E-06 M W.V U Sample Remark

6 Table 1. The retention/excretion values calculated by the LUDEP software following a single intake of 1 Bq for days Inhalation case (Cont.) m(t) Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Lung Model Biokinetic Model Sample Remark Ra E E E E E E E E E E-02 M W.V WB Ra E E E E E E E E E E-06 M W.V U Th E E E E E E E E E E-05 M W U Th E E E E E E E E E E-02 M W WB Th E E E E E E E E E E-05 M W U U E E E E E E E E E E-02 M W.V Lu U E E E E E E E E E E-05 M W.V U U E E E E E E E E E E-02 M W.V Lu U E E E E E E E E E E-05 M W.V U U E E E E E E E E E E-02 M W.V Lu U E E E E E E E E E E-05 M W.V U Np E E E E E E E E E E-02 M W.M Lu Np-237 no data Pu E E E E E E E E E E-02 M W.M Lu ICRP 54 Pu E E E E E E E E E E-06 M W.M U ICRP 54 Pu E E E E E E E E E E-02 M W.M Lu ICRP 54 Pu E E E E E E E E E E-06 M W.M U ICRP 54 Pu E E E E E E E E E E-02 M W.M Lu ICRP 54 Pu E E E E E E E E E E-06 M W.M U ICRP 54 Am E E E E E E E E E E-02 M W.M Lu ICRP 54 Am E E E E E E E E E E-06 M W.M U ICRP 54 Cm E E E E E E E E E E-03 M W.M Lu Cm-242 no data Cm E E E E E E E E E E-02 M W.M Lu Cm-244 no data Cf E E E E E E E E E E-02 M W.M Lu Cf-252 no data

7 Table 2. The retention/excretion values given in the ICRP Publications No 54 and 78 corresponding to 1 Bq single intake Inhalation case m(t) Lung ICRP Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Model Sample Model H-3 2.3E E E E E-03 HTO U 78 P E E E E-03 W U 54 Cr E E E E E E-02 W WB 54 Cr-51 no data Mn E E E E E E E E-02 W WB 54 Mn-54 no data Fe E E E E E E E E-02 M WB 78 Fe E E E E E E E E-07 M U 78 Co E E E E E E E E E-02 M WB 78 Co E E E E E E E E E-05 M U 78 Co E E E E E E E E-02 M WB 78 Co E E E E E E E E-05 M U 78 Co E E E E E E E E E E-02 M WB 78 Co E E E E E E E E E E-05 M U 78 Sr E E E E E E E E E-02 S WB 78 Sr E E E E E E E E E-06 S U 78 Sr E E E E E-05 S U 78 Sr E E E E E E E E E E-06 S U 78 Zr E E E E E E E E-02 W WB 54 Zr-95 no data Ru E E E E E E E E E E-02 M WB 78 Ru E E E E E E E E E E-05 M U 78 Ag-110m 5.9E E E E E E E E-01 W WB 54 Ag-110m no data

8 Table 2. The retention/excretion values given in the ICRP Publications No 54 and 78 corresponding to 1 Bq single intake Inhalation case (Cont.) m(t) Lung ICRP Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Model Sample Model Sb E E E E E E E-02 M WB 54 Sb-124 no data Sb E E E E E E E E-02 M WB 54 Sb-125 no data I E E E E E E E E-02 F Th 78 I E E E E E E E E-04 F U 78 I E E E E E E E E E E-02 F Th 78 I E E E E E E E E E E-04 F U 78 I E E E E E-02 F Th 78 I E E E E E-05 F U 78 Cs E E E E E E E E E-01 F WB 78 Cs E E E E E E E E E-03 F U 78 Cs E E E E E E E E E E-01 F WB 78 Cs E E E E E E E E E E-04 F U 78 Ce E E E E E E E E E-02 W WB 54 Ce E E E E E E E E E-07 W U 54 Ce E E E E E E E E E E-02 W WB 54 Ce E E E E E E E E E E-06 W U 54 Hg E E E E E E-01 W WB 54 Hg-203 no data Ra E E E E E E E E E E-02 M WB 78 Ra E E E E E E E E E E-06 M U 78 Ra E E E E E E E E E E-02 M WB 78 Ra E E E E E E E E E E-06 M U 78 Th E E E E E E E E E E-02 M WB 78 Th E E E E E E E E E E-06 M U 78

9 Table 2. The retention/excretion values given in the ICRP Publications No 54 and 78 corresponding to 1 Bq single intake Inhalation case (Cont.) m(t) Lung ICRP Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Model Sample Model Th E E E E E E E E E E-02 M WB 78 Th E E E E E E E E E E-06 M U 78 U E E E E E E E E E E-02 M Lu 78 U E E E E E E E E E E-05 M U 78 U E E E E E E E E E E-02 M Lu 78 U E E E E E E E E E E-05 M U 78 U E E E E E E E E E E-02 M Lu 78 U E E E E E E E E E E-05 M U 78 Np E E E E E E E E E E-02 M Lu 78 Np E E E E E E E E E E-05 M U 78 Pu E E E E E E E E E E-02 M Lu 78 Pu E E E E E E E E E E-06 M U 78 Pu E E E E E E E E E E-02 M Lu 78 Pu E E E E E E E E E E-06 M U 78 Pu E E E E E E E E E E-02 M Lu 78 Pu E E E E E E E E E E-06 M U 78 Am E E E E E E E E E E-02 M Lu 78 Am E E E E E E E E E E-05 M U 78 Cm E E E E E E E E E-02 M Lu 78 Cm E E E E E E E E E-05 M U 78 Cm E E E E E E E E E E-02 M Lu 78 Cm E E E E E E E E E E-05 M U 78 Cf E E E E E E E E E E-02 M Lu 78 Cf E E E E E E E E E E-06 M U 78

10 Table 3. The relative differences of the results of calculations by LUDEP given as percentages of the retention/excretion values of the ICRP Publications No 54 and 78 Inhalation case Relative difference (%) Lung ICRP Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Model Sample Model H HTO U 78 P W U 54 Cr W WB 54 Cr-51 no data Mn W WB 54 Mn-54 no data Fe M WB 78 Fe-59 no data M U 78 Co M WB 78 Co M U 78 Co M WB 78 Co M U 78 Co M WB 78 Co M U 78 Sr S WB 78 Sr S U 78 Sr S U 78 Sr S U 78 Zr W WB 54 Zr-95 no data Ru M WB 78 Ru M U 78 Ag-110m W WB 54 Ag-110m no data

11 Table 3. The relative differences of the results of calculations by LUDEP given as percentages of the retention/excretion values of the ICRP Publications No 54 and 78 Inhalation case (Cont.) Relative difference (%) Lung ICRP Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Model Sample Model Sb W WB 54 Sb-124 no data Sb W WB 54 Sb-125 no data I F Th 78 I F U 78 I F Th 78 I F U 78 I F Th 78 I F U 78 Cs F WB 78 Cs F U 78 Cs F WB 78 Cs F U 78 Ce W WB 54 Ce W U 54 Ce W WB 54 Ce W U 54 Hg W WB 54 Hg-203 no data Ra M WB 78 Ra M U 78 Ra M WB 78 Ra M U 78 Th M WB 78 Th M U 78

12 Table 3. The relative differences of the results of calculations by LUDEP given as percentages of the retention/excretion values of the ICRP Publications No 54 and 78 Inhalation case (Cont.) Relative difference (%) Lung ICRP Nuclide 1d 2d 5d 10d 15d 30d 45d 60d 90d 180d Model Sample Model Th M WB 78 Th M U 78 U M Lu 78 U M U 78 U M Lu 78 U M U 78 U M Lu 78 U M U 78 Np M Lu 78 Np-237 no data Pu M Lu 78 Pu M U 78 Pu M Lu 78 Pu M U 78 Pu M Lu 78 Pu M U 78 Am M Lu 78 Am M U 78 Cm M Lu 78 Cm-242 no data Cm M Lu 78 Cm-244 no data Cf M Lu 78 Cf-252 no data

13 Table 4. The inhalation dose factors calculated by the LUDEP software and the relative differences as percentages of the values of IAEA Basic Safety Standards Relative difference (%) Nuclide LUDEP IBSS Lung Biokinetic Daughters Model Model included Remark H-3 1.8E E HTO ingestion P E E M W Cr E E M W.V Mn E E M W Fe E E M W Co E E M W Co E E M W Co E E M W Zn E E S Y.V Rb E E F D Sr E E S Y.S Sr E E S Y.S Sr E E S Y.S Y-90 Zr E E M W Ru E E M W Rh-106 Ag-110m 5.5E E M W Ag-110 Sb E E M W Sb E E M W Te-125m I E E F D I E E F D I E E F D Cs E E F D Cs E E F D Ba-137m Ba E E F D.V Ce E E M W Ce E E M W Pr-144m, Pr-144 Hg E E M W.I Ra E E M W.V Ra E E M W.V Ac-228, Ra-224 Th E E M W Ra-224 Th E E M W U E E M W.V U E E M W.V Th-231 U E E M W.V Th-234, Pa-234m, Pa-234 Np E E M W.M Pa-233 Pu E E M W.M Pu E E M W.M Pu E E M W.M Am E E M W.M Cm E E M W.M Cm E E M W.M Cf E E M W.M

14 Table 5. The retention/excretion values calculated by the LUDEP software following a single intake of 1 Bq for 1-10 days Ingestion case m(t) Biokinetic Nuclide 1d 2d 5d 10d f 1 Model Sample Remark H-3 2.2E E E E-02 1(HTO) U A P E E E E W U B Cr E E E E ING.V WB Cr-51 no data Mn E E E E W WB Mn-54 no data 0.1 Fe E E E E W WB Fe-59 no data Co E E E E W WB Co E E E E W U Co E E E E W WB Co E E E E W U Co E E E E W WB Co E E E E W U Sr E E E E D.V WB Sr E E E E D.V U Sr E E E E D.V U Sr E E E E D.V U Zr E E E E W WB Zr-95 no data Ru E E E E W WB Ru E E E E W U Ag-110m 7.3E E E E W WB Ag-110m no data Sb E E E E W WB Sb-124 no data Sb E E E E W WB Sb-125 no data I E E E E-01 1 D Th I E E E E-04 1 D U I E E E E-01 1 D Th I E E E E-04 1 D U I E E E E-01 1 D Th I E E E E-04 1 D U Cs E E E E-01 1 D WB Cs E E E E-03 1 D U Cs E E E E-01 1 D WB Cs E E E E-03 1 D U A) there is no built in excretion function in LUDEP; B) the c2 parameter is wrong in the excretion function in LUDEP (typing error)

15 Table 5. The retention/excretion values calculated by the LUDEP software following a single intake of 1 Bq for 1-10 days Ingestion case (Cont.) m(t) Biokinetic Nuclide 1d 2d 5d 10d f 1 Model Sample Remark Ce E E E E W WB Ce E E E E W U Ce E E E E W WB Ce E E E E W U Hg E E E E (Inorg.) W.I WB Hg-203 no data Ra E E E E W.V WB Ra E E E E W.V U Ra E E E E W.V WB Ra E E E E W.V U Th E E E E W WB Th E E E E W U Th E E E E W WB Th E E E E W U U-234 no data U E E E E W.V U U-235 no data U E E E E W.V U U-238 no data U E E E E W.V U Np E E E E W.M Skel Np-237 no data Pu-238 no data Pu E E E E W.M U Pu-239 no data Pu E E E E W.M U Pu-240 no data Pu E E E E W.M U Am E E E E W.M Skel Am E E E E W.M U Cm-242 no data Cm-242 no data Cm-244 no data Cm-244 no data Cf-252 no data Cf-252 no data

16 Table 6. The retained or excreted activity values given in the ICRP Publication No 78 corresponding to 1 Bq single intake Ingestion case m(t) f 1 Sample Nuclide 1d 2d 5d 10d H-3 2.3E E E E-02 1(HTO) U P-32 no data Cr-51 no data Cr-51 no data Mn-54 no data Mn-54 no data Fe E E E E WB Fe E E E E U Co E E E E WB Co E E E E U Co E E E E WB Co E E E E U Co E E E E WB Co E E E E U Sr E E E E WB Sr E E E E U Sr E E E E U Sr E E E E U Zr-95 no data Zr-95 no data Ru E E E E WB Ru E E E E U Ag-110m no data Ag-110m no data Sb-124 no data Sb-124 no data Sb-125 no data Sb-125 no data I E E E E-01 1 Th I E E E E-04 1 U I E E E E-01 1 Th I E E E E-04 1 U I E E E E-01 1 Th I E E E E-04 1 U Cs E E E E-01 1 WB Cs E E E E-03 1 U Cs E E E E-01 1 WB Cs E E E E-03 1 U Ce-141 no data Ce-141 no data Ce-144 no data Ce-144 no data Hg-203 no data Hg-203 no data

17 Table 6. The retained or excreted activity values given in the ICRP Publication No 78 corresponding to 1 Bq single intake Ingestion case (Cont.) ICRP (d) f 1 Sample Nuclide 1d 2d 5d 10d Ra E E E E WB Ra E E E E U Ra E E E E WB Ra E E E E U Th E E E E WB Th E E E E U Th E E E E WB Th E E E E U U-234 no data U E E E E U U-235 no data U E E E E U U-238 no data U E E E E U Np E E E E Skel Np E E E E U Pu-238 no data Pu E E E E U Pu-239 no data Pu E E E E U Pu-240 no data Pu E E E E U Am E E E E Skel Am E E E E U Cm-242 no data Cm E E E E U Cm-244 no data Cm E E E E U Cf-252 no data Cf E E E E U

18 Table 7. The relative differences of the results of calculations by LUDEP given as percentages of retained or excreted activity values of the ICRP Publications No 78 Ingestion case Relative difference (%) Biokinetic Nuclide 1d 2d 5d 10d f 1 Model Sample H (HTO) U P-32 no data Cr-51 no data Cr-51 no data Mn-54 no data Mn-54 no data Fe W WB Fe-59 no data Co W WB Co W U Co W WB Co W U Co W WB Co W U Sr D.V WB Sr D.V U Sr D.V U Sr D.V U Zr-95 no data Zr-95 no data Ru W WB Ru W U Ag-110m no data Ag-110m no data Sb-124 no data Sb-124 no data Sb-125 no data Sb-125 no data I D Th I D U I D Th I D U I D Th I D U Cs D WB Cs D U Cs D WB Cs D U Ce-141 no data Ce-141 no data Ce-144 no data Ce-144 no data

19 Table 7. The relative differences of the results of calculations by LUDEP given as percentages of retained or excreted activity values of the ICRP Publications No 78 Ingestion case Relative difference (%) Biokinetic Nuclide 1d 2d 5d 10d f 1 Model Sample Hg-203 no data Hg-203 no data Ra W.V WB Ra W.V U Ra W.V WB Ra W.V U Th W WB Th W U Th W WB Th W U U-234 no data U D.V U U-235 no data U D.V U U-238 no data U D.V U Np W.M Skel Np-237 no data Pu-238 no data Pu W.M U Pu-239 no data Pu W.M U Pu-240 no data Pu W.M U Am W.M Skel Am W.M U Cm-242 no data Cm-242 no data Cm-244 no data Cm-244 no data Cf-252 no data Cf-252 no data

20 Table 8. The ingestion dose factors calculated by the LUDEP software and the relative differences as percentages of the values of IAEA Basic Safety Standards Relative difference (%) Biokinetic Nuclide LUDEP IBSS f 1 Model Daughters included H-3 1.8E E (HTO) P E E W Cr E E ING.V Mn E E W Fe E E W Co E E W Co E E W Co E E W Zn E E Y.V Rb E E D Sr E E D.V Sr E E D.V Sr E E D.V Y-90 Zr E E W Ru E E W Rh-106 Ag-110m 2.5E E W Ag-110 Sb E E D Sb E E D Te-125m I E E D I E E D I E E D Cs E E D Cs E E D Ba-137m Ba E E D.V La-140 Ce E E W Ce E E W Pr-144m,Pr-144 Hg E E (Inorg) W.I Ra E E W.V Ra E E W.V Ac-228 Th E E W Ra-224 Th E E W U E E D.V U E E D.V Th-231 U E E D.V Th-234,Pa-234m,Pa-234 Np E E W.M Pa-233 Pu E E W.M Pu E E W.M Pu E E W.M Am E E W.M Cm E E W.M Cm E E W.M Cf E E W.M