Update on IA IAEA profic iciency te test exe xercises Arend Harms and Iolanda Osvath IAEA Environment Laboratories Monaco IAEA International Atomic Energy Agency
2015 IA IAEA pro roficiency test exe xercise (in (introduction) • 2015 IAEA proficiency test exercise organised in cooperation with the Nuclear Regulation Authority (Japan) • 26 participants, including 7 from HELCOM contracting parties Estonia Finland Germany Poland the Russian Federation Sweden • 10 participants from Japan IAEA
2015 IA IAEA pro roficiency test exe xercise (s (samples) Samples supplied containing 5 L of Mediterranean sea water spiked with known amounts of H-3, Sr-90, Cs-134 and Cs-137 Suggested analytical method H-3: Distillation and liquid scintillation counting Sr-90: Ca/Sr precipitation followed by extraction and/or chromatography and LSC or GF-proportional counting Cs-134 and Cs-137: - Either direct gamma spectrometry (GS) or - adsorption on (NH 4 ) 3 PO 4 Mo 12 O 36 or Cu 2 [Fe(CN) 6 ] and GS IAEA
2015 IA IAEA pro roficiency test exe xercise (a (assigned valu lues) Individual unique sea water samples prepared separately. Traceable massic activities in samples: H-3: : (3.14 - 3.22) Bq kg -1 Sr Sr-90 90: (0.1001 - 0.1027) Bq kg -1 Cs Cs-134: (0.1531 - 0.1571) Bq kg -1 Cs Cs-137: (0.2027 - 0.2080) Bq kg -1 IAEA
Evalu luation of f re results (T (Test I) I) 𝑆𝑓𝑚𝑏𝑢𝑗𝑤𝑓 𝑐𝑗𝑏𝑡 = 𝑊𝑏𝑚𝑣𝑓 𝐵𝑜𝑏𝑚𝑧𝑡𝑢 − 𝑊𝑏𝑚𝑣𝑓 𝐽𝐵𝐹𝐵 × 100% 𝑊𝑏𝑚𝑣𝑓 𝐽𝐵𝐹𝐵 3 H and 90 Sr If absolute value of relative bias < 25%: “Pass” otherwise: “Fail” 134 Cs and 137 Cs If absolute value of relative bias < 20%: “Pass” otherwise: “Fail” IAEA
Evalu luation of f re results (t (two additional Tests II II and II III) I) A 1 ≤ A 2 where: 𝐵 1 = 𝑊𝑏𝑚𝑣𝑓 𝐽𝐵𝐹𝐵 − 𝑊𝑏𝑚𝑣𝑓 𝐵𝑜𝑏𝑚𝑧𝑡𝑢 2 2 𝐵 2 = 2.58 × 𝑣𝑜𝑑 𝐽𝐵𝐹𝐵 + 𝑣𝑜𝑑 𝐵𝑜𝑏𝑚𝑧𝑡𝑢 P < P < 25 25% (f (for 3 H an and 90 90 Sr) or P < < 20 20% ( % ( 134 134 Cs an and 137 137 Cs) where: 2 2 𝑣𝑜𝑑 𝐽𝐵𝐹𝐵 𝑣𝑜𝑑 𝐵𝑜𝑏𝑚𝑧𝑡𝑢 𝑄 = + × 100% 𝑊𝑏𝑚𝑣𝑓 𝐽𝐵𝐹𝐵 𝑊𝑏𝑚𝑣𝑓 𝐵𝑜𝑏𝑚𝑧𝑡𝑢 IAEA
Evalu luation Tes est t I. I. Rel elati tive bia bias tes test: Pas ass or or Fa Fail il Test II. Zeta score Pass or Fail Test III. Precision test Pass or Fail Test I Test II Test III Final evaluation Pass Pass Pass Accepted Pass Fail Pass Warning Pass Pass Fail Warning Fail Pass/Fail Pass/Fail Not Accepted IAEA
Evalu luation IAEA
H-3 3 (a (all ll participants) IAEA
H-3 3 (H (HELCOM) IAEA
H-3 3 (H (HELCOM) IAEA
Sr Sr-90 (a (all l participants) IAEA
Sr-90 (H Sr (HELCOM) IAEA
Sr-90 (H Sr (HELCOM) IAEA
Cs-134 (a Cs (all ll participants) IAEA
Cs Cs-134 (H (HELCOM) IAEA
Cs-134 (H Cs (HELCOM) IAEA
Cs Cs-137 (a (all ll participants) IAEA
Cs Cs-137 (H (HELCOM) IAEA
Cs-137 (H Cs (HELCOM) IAEA
Overview H-3 Sr-90 Cs-134 Cs-137 All (81 results) Acceptable 11 12 17 23 Warning 1 0 4 0 Not Acceptable 4 1 5 3 HELCOM (23 results) Acceptable 2 5 2 7 Warning 0 0 2 0 Not Acceptable 2 0 3 0 IAEA
Comparison between data sets (Bq Bq kg kg -1 ) ) H-3 Sr-90 3.205 0.023 0.1020 0.0008 Assigned value 3.7 0.3 0.1022 0.0020 HELCOM Bias 16% 0.2% Significant? No No 3.184 0.020 0.1014 0.0008 Assigned value 3.09 0.04 0.1023 0.0013 All par arti ticipants Bias -2.9% 1.0% Significant? No No IAEA
Comparison between data sets (Bq Bq kg kg -1 ) Cs-134 Cs-137 0.1556 0.0012 0.2060 0.0015 Assigned value 0.141 0.006 0.206 0.005 HELCOM Bias -9.6% -0.2% Significant? No No 0.1547 0.0011 0.2048 0.0014 Assigned value 0.1488 0.0024 0.208 0.003 All par arti ticipants Bias: -3.8% 1.5% Significant? Yes No IAEA
Overview HELCOM in in PTEs 2012 2012-2015 2015 2015 2014 2013 2012 Accepted 70 70% 70% 80% 100% Warning 9% 15% 15% 0% Not Accepted 22 22% 15% 5% 0% Participants 7 6 7 2 Results 23 23 20 20 4 Radionuclides 4 4 3 2 IAEA
HELCOM Cs-134 in in PTEs 2012 2012-2015 2015 2014 2013 2012 Accepted 29 29% 67% 86% 100% Warning 29 29% 0% 14% 0% Not Accepted 43 43% 33% 0% 0% Results 7 6 7 2 Bias -9.6% -9.2% -1.4% -10% Bias significant? No No Yes No No IAEA
Conclu lusion Some participants seem not to make sufficient correction for coincidence summing (signal loss -> underestimation of the Cs-134 activity level) Spread in the reported relative uncertainties (at k =1): All participants HELCOM H-3: 1.8% - 33% 10% - 23% Sr-90: 2.2% - 20% 2.6% - 20% Cs-134: 4.8% - 23% 4.9% - 15% Cs-137: 3.0% - 15% 4.6% - 15% IAEA
Acknowledgements Many thanks to the participants for submitting their results Special acknowledgements to our IAEA colleagues Mai Pham and Oxana Blinova for technical assistance The IAEA is grateful to the Government of the Principality of Monaco for the support provided to its Environment Laboratories IAEA
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