evaluation of the 2016 env57/metroerm measurement ... of the 2016 env57/metroerm measurement...

Timotheos Altzitzoglou

Petya Malo

Evaluation of the 2016 ENV57/MetroERM

measurement comparison on simulated

airborne particulates: 137Cs, 134Cs and 131I in air filters

2017

EUR xxxxx xx (in

white where

appropriate)

EUR 28431 EN

This publication is a Technical report by the Joint Research Centre (JRC), the European Commissions science

and knowledge service. It aims to provide evidence-based scientific support to the European policymaking

process. The scientific output expressed does not imply a policy position of the European Commission. Neither

the European Commission nor any person acting on behalf of the Commission is responsible for the use that

might be made of this publication.

Contact information

Name: Timotheos Altzitzoglou

Address: European Commission, Joint Research Centre, Directorate for Nuclear Safety and Security

Email: timotheos.altzitzoglou@ec.europa.eu

Tel.: +32 14 571266

JRC Science Hub

https://ec.europa.eu/jrc

JRC105477

EUR 28431 EN

PDF ISBN 978-92-79-65276-9 ISSN 1831-9424 doi:10.2760/030337

Luxembourg: Publications Office of the European Union, 2017

European Atomic Energy Community, 2017

The reuse of the document is authorised, provided the source is acknowledged and the original meaning or

message of the texts are not distorted. The European Commission shall not be held liable for any consequences

stemming from the reuse.

How to cite this report: Timotheos Altzitzoglou, Petya Malo; Evaluation of the 2016 ENV57/MetroERM

measurement comparison on simulated airborne particulates: 137Cs, 134Cs and 131I in air filters; EUR 28431 EN;

doi:10.2760/030337

All images European Atomic Energy Community, 2017

Contents

Acknowledgements ............................................................................................ 1

Abstract ........................................................................................................... 3

1. Introduction ............................................................................................... 5

2. The 2016 ENV57 MetroERM measurement comparison ..................................... 7

2.1 Description of the sample ........................................................................ 7

2.2 Participating laboratories ......................................................................... 7

2.3 Reporting of results ................................................................................ 8

2.4 Timetable of the ILC ............................................................................... 8

3. The Reference value .................................................................................... 9

3.1 Standardisation of the spike solution ......................................................... 9

3.1.1 137Cs ............................................................................................. 10

3.1.2 134Cs ............................................................................................. 11

3.1.3 131I ................................................................................................ 11

3.2 Dilutions .............................................................................................. 12

3.3 Spiking of the air filters ......................................................................... 14

3.4 Reference values .................................................................................. 14

3.5 Quality control measurements ................................................................ 15

3.6 Influence of discrete spiked activity distribution on the counting efficiency... 15

4. Questionnaire on sampling method, air filter used and measurement conditions 20

5. Questionnaire on analytical and measurement procedures ............................. 21

6. Evaluation and comparison of the results ..................................................... 22

6.1 Identification of outliers and normal distribution test ................................. 22

6.2 Scores and evaluation criteria ................................................................ 23

6.2.1 Percentage difference ...................................................................... 23

6.2.2 En number ...................................................................................... 24

6.2.3 Compatibility test ............................................................................ 24

6.2.4 PomPlot ......................................................................................... 24

7. Results .................................................................................................... 26

7.1 137Cs ................................................................................................... 26

7.1.1 Reported results ............................................................................. 26

7.1.2 Evaluation ...................................................................................... 31

7.1.3 Parameters possibly influencing the results ........................................ 35

7.1.4 Comparison to the 2003 and the 2014 EC ILC .................................... 36

7.2 134Cs ................................................................................................... 38

7.2.1 Reported results ............................................................................. 38

7.2.2 Evaluation ...................................................................................... 43

7.2.3 Parameters possibly influencing the results: Coincidence summing

correction ............................................................................................... 46

7.3 131I ..................................................................................................... 48

7.3.1 Reported results ............................................................................. 48

7.3.2 Evaluation ...................................................................................... 54

7.3.3 Parameters possibly influencing the results ........................................ 58

7.3.3.1 Decay during measurement ........................................................... 58

7.3.3.2 Coincidence summing correction .................................................... 59

7.3.3.3 Radioactivity transferred to the protective plastic bag ....................... 59

7.3.4 Conclusions .................................................................................... 61

8. Conclusions .............................................................................................. 63

References...................................................................................................... 69

List of abbreviations and definitions ................................................................... 71

List of figures .................................................................................................. 73

List of tables ................................................................................................... 75

ANNEXES........................................................................................................ 78

Annex 1: List of participating laboratories per country (in alphabetic order) ...... 78

Annex 2: Communication to the participants ................................................. 87

2A. Expression of interest ........................................................................... 87

2B. Invitation e-mail and accompanying letter ............................................... 89

2C. Registration information (e-mail) ............................................................ 91

2D. Spiked air filter dispatch (e-mail) and accompanying letter ........................ 92

2E. Information to participants during the measurement exercise .................... 95

2F. Reporting results .................................................................................. 96

2G. Communication of preliminary results to the participants .......................... 97

2H. Invitation to the Workshop ................................................................... 101

Annex 3: First questionnaire sent to the participants to collect information on air filters and sampling ................................................................................... 106

Annex 4: Responses of the participants to the questionnaire for collecting

information on air filters and sampling ......................................................... 109

Annex 5: Type, material, size and form of the air filters used by the participants .............................................................................................................. 112

Annex 6: Sequence of spiked filters and quality control sources prepared for the

1026 ENV57/MetroERM ILC exercise ............................................................ 115

Annex 7: Examples of spiked filters ............................................................. 117

Annex 8: Quality control filters and sources; measurement results and their

deviation from the reference activity values ................................................. 118

Annex 9: Reporting form and second questionnaire for submitting the measurement results ............................................