Metrology for the mobile detection of ionising radiation following a nuclear or radiological incident - “Preparedness”

Postprint (published version

Overview of passive area dosimetry systems used in European countries

EURADOS Working Group 3 (WG3) aims at providing information about the correct measurement of the ambient dose equivalent, short H*(10), in the environment and has a specific subgroup (WG3-SG2) that focuses on passive environmental dosimetry. One of the initial tasks of the subgroup was to gather information on passive area dosimetry for workplace and environmental radiation monitoring. This information has been obtained from dosimetry services using passive H*(10) photon or neutron dosemeters. On the basis of surveys performed in 2012 and 2016 this report summarizes the situation of passive environmental dosimetry in European countries. The results were treated confidentially. Therefore, the present document shows anonymous statistical evaluations. The gathered facts helped, in particular, to prepare related intercomparisons. Some open questions have been identified, especially concerning the harmonization of environmental dosimetry since many different protocols, dosimetry systems, calibration procedures, regulations and laws exist.Postprint (published version

Recommendations to harmonise European early warning dosimetry network systems

After the Chernobyl nuclear power plant accident in 1986, followed by the Fukushima Nuclear power plant accident 25 years later, it became obvious that real-time information is required to quickly gain radiological information. As a consequence, the European countries established early warning network systems with the aim to provide an immediate warning in case of a major radiological emergency, to supply reliable information on area dose rates, contamination levels, radioactivity concentrations in air and finally to assess public exposure. This is relevant for governmental decisions on intervention measures in an emergency situation. Since different methods are used by national environmental monitoring systems to measure area dose rate values and activity concentrations, there are significant differences in the results provided by different countries. Because European and neighboring countries report area dose rate data to a central data base operated on behalf of the European Commission, the comparability of the data is crucial for its meaningful interpretation, especially in the case of a nuclear accident with transboundary implications. Only by harmonizing measuring methods and data evaluation, is the comparability of the dose rate data ensured. This publication concentrates on technical requirements and methods with the goal to effectively harmonize area dose rate monitoring data provided by automatic early warning network systems. The requirements and procedures laid down in this publication are based on studies within the MetroERM project, taking into account realistic technical approaches and tested procedures.JRC.G.10-Knowledge for Nuclear Security and Safet

Measurements of 60Co in massive steel samples exposed to the Hiroshima atomic bomb explosion

To study discrepancies in retrospective Hiroshima dosimetry, the specific activity of 60Co in 16 steel samples from Hiroshima was measured using gamma-ray spectrometry in underground laboratories. There is general agreement between these new activity measurements and the specific activities derived from previously calculated dose values on the one hand and former measurements of samples gathered at distances less than 1,000 m from the center of the explosion (less tahn 1,000 m slant range) on the other. It was found that activities at long range (more than 1,300 m slant range) were mainly cosmogenically induced. Furthermore, at long range, these results are in disagreement with older measurements whose specific activity values were 10 to 100 times higher than predicted by computer model calculations in DS86 and DS02. As a consequence, the previously reported discrepancy is not confirmed.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Low-Level Gamma-Ray Spectrometry for Analysing Fusion Plasma Conditions

A new method, combining activation by neutrons and charged particles with ultra low-level gamma-ray spectrometry, aimed at obtaining a better understanding and more adequate measurements of MeV particle leaks in magnetic fusion devices was studied here. A total of 36 samples containing Ti, LiF, B4C and W were placed in a boron nitride holder mounted on the ceiling of the JET Tokamak. The samples were activated by 63 pulses from a D-3He plasma and were later measured using underground gamma-ray spectrometry. The radionuclides 7Be, 46Sc, 54Mn, 56Co, 57Co, 58Co, 124Sb, 181Hf, 182Ta, 181W and 185W were detected in several of the samples, very low levels of activity of 47Sc and 48V being found in a few of the samples. The various production channels for the radionuclides in question are discussed.JRC.D.4-Isotope measurement

Angular Distribution of Proton Leakage from a Fusion Plasma Using Ultra Low-Level Gamma-Ray Spectrometry

This experiment aimed at studying a technique to measure the leakage of charged particles from a fusion plasma. The activity induced in samples of various materials placed on a special holder inside a Tokamak was measured using ultra low-level gamma-ray spectrometry (ULGS) performed in three underground laboratories. In total, 27 radionuclides were detected in this experiment. Seven of these radionuclides were mainly produced by proton interactions. For two of them it was possible to determine their angular distribution.JRC.D.4-Nuclear physic

Status of passive environmental dosimetry in Europe

EURADOS Working Group 3 (WG3) aims at providing information about the correct measurement of the ambient dose equivalent (rate) in the environment and has a specific subgroup (WG3-SG2) that focuses on passive environmental dosimetry. One of the initial tasks of the subgroup was to gain an overview of passive dosimetry practices in Europe. On the basis of a survey carried out by this subgroup in 2013/2014, information on the state-of-the-art was gained, several conclusions were drawn and some open questions have been identified, e.g. the harmonization in the terminology, uncertainty assessment procedures and corrections of measured values by passive dosemeters due to transport and climate