22NRM07 GuideRadPROS: Radiation protection dosimeter performance assessment – Aggregated calibration data in the Cs-137 reference radiation field

One of the goals of the GuideRadPROS joint research project (JRP) is the harmonization and update of international standards for type testing of radiation protection dosimeters. This is to be achieved through analysis of the test methods and criteria of evaluation of dosimeters defined in different standards, and through analysis of the performance of radiation protection dosimeters used in different European countries. Within one of the activities under the WP3 of this JRP, most commonly used active radiation protection dosimeters used for area monitoring in the workplace and for individual monitoring of occupationally exposed workers have been identified. Aggregated calibration data on several radiation protection dosimeter models have been collected from a total of six dosimetry calibration laboratories. The collected calibration data predominantly includes calibration at the radionuclide-based radiation qualities (termed as S-Cs and S-Co in the ISO 4037 standard). The calibrations are usually performed in these radiation fields at various dose rate and dose values. This data can be used to assess the dosimeter performance in terms of response non-linearity. Calibrations in the N-series radiation qualities are either not commonly requested by the end-users or not regularly provided by the calibration laboratories. In this work, aggregated calibration data in terms of absolute dosimeter response have been presented. The collected calibration data is presented for S-Cs at the reference dose (rate). Intervariation of dosimeter response within a dosimeter model of up to approximately 10 % can be observed. The cause of this variation can be addressed to the dosimeters being used in different environments, with different frequencies of use, as well as the differences between the data originating from several calibration laboratories. For some dosimeter models the conclusions on the behavior of dosimeter type under reference conditions cannot be clearly deducted due to the low sample size. The response of all the calibrated dosimeters is within ± 40 %. The aggregated calibration data, along with the data on dosimeter performance from the literature, and the state-of-the-art manufacturer specifications will be used to identify the gaps in the data on radiation protection dosimeters. A measurement program is currently ongoing and being conducted under the scope of the JRP, to collect additional data on dosimeter performance including their energy and angular dependence of the response as well as their non-linearity.