ISO/TC 85/SC 2/WG 19 - Individual monitoring of external radiation

The quality of a supplier of a dosimetry service depends on both the characteristics of the approved (type‑tested) dosimetry system[1] and the training and experience of the staff, together with the calibration procedures and quality assurance programmes. This document specifies the criteria and the test procedures to be used for the periodic verification of the performance of dosimetry services supplying personal and/or area dosemeters. An area dosemeter can be a workplace dosemeter or an environmental dosemeter. The performance evaluation can be carried out as a part of the approval procedure for a dosimetry system or as an independent check to verify that a dosimetry service fulfils specified national or international type test performance requirements under representative exposure conditions that are expected or mimic workplace fields from the radiological activities being monitored. This document applies to personal and area dosemeters for the assessment of external photon radiation with a (fluence weighted) mean energy between 8 keV and 10 MeV, beta radiation with a (fluence weighted) mean energy between 60 keV and 1,2 MeV, and neutron radiation with a (fluence weighted) mean energy between 25,3 meV (i.e. thermal neutrons with a Maxwellian energy distribution with kT = 25,3 meV) and 200 MeV. It covers all types of personal and area dosemeters needing laboratory processing (e.g. thermoluminescent, optically stimulated luminescence, radiophotoluminescent, track detectors or photographic-film dosemeters) and involving continuous measurements or measurements repeated regularly at fixed time intervals (e.g. several weeks, one month). Active dosemeters (for dose measurement) may also be treated according to this document. Then, they should be treated as if they were passive (i.e. the dosimetry service reads their indicated values and reports them to the evaluation organization). [1] If this document is applied to a dosimetry system for which no approval (pattern or type test) has been provided, then in the following text approval or type test should be read as the technical data sheet provided by the manufacturer or as the data sheet required by the regulatory authority.

ISO 21909-1:2015 provides performance and test requirements for determining the acceptability of neutron dosimetry systems to be used for the measurement of personal dose equivalent, Hp(10), for neutrons ranging in energy from thermal to 20 MeV[1]. No distinction between the different techniques available in the market place is made in the description of the tests. Only generic distinctions, as disposable or reusable dosemeters for instance, are considered. This part of ISO 21909 gives information for extremity dosimetry, based on recommendations given by ICRU Report 66 in Annex A. [1] This maximal limit of the energy range is only an order of magnitude. The reference radiation fields used for the performance tests are those defined in ISO 8529-1. This means that the maximal energies could only be 14,8 MeV or 19 MeV. The present standard gives performance requirements to 14,8 MeV which is the typical neutron energy encountered for fusion. For fission spectra, the highest energies are around 20 MeV but the contribution to dose equivalent coming from neutrons with energy higher than 14,8 MeV is negligible.

ISO 15382:2015 provides procedures for monitoring the dose to the skin, the extremities, and the lens of the eye. It gives guidance on how to decide if such dosemeters are needed and to ensure that individual monitoring is appropriate to the nature of the exposure, taking practical considerations into account. National regulations, if they exist, provide requirements that need to be followed. ISO 15382:2015 specifies procedures for individual monitoring of radiation exposure of the skin, extremities (hands, fingers, wrists, forearms, feet and ankles), and lens of the eye in planned exposure situations. It covers practices which involve a risk of exposure to photons in the range of 8 keV to 10 MeV and electrons and positrons in the range of 60 keV to 10 MeV. ISO 15382:2015 gives guidance for the design of a monitoring program to ensure compliance with legal individual dose limits. It refers to the appropriate operational dose quantities, and it gives guidance on the type and frequency of individual monitoring and the type and positioning of the dosemeter. Finally, different approaches to assess and analyse skin, extremity, and lens of the eye doses are given. It is not in the scope of this International Standard to consider exposure due to alpha or neutron radiation fields.

ISO 21909:2005 provides performance and test requirements for determining the acceptability of personal neutron dosemeters to be used for the measurement of personal dose equivalent, Hp(10) for neutrons ranging in energy from thermal to 20 MeV.