BSI 20/30374345 DC 2020

No qualification or correction of the dosimetry system at a workplace is required if the dosimetry system fulfils the criteria of ISO 21909-1. However, methodologies described in this document can be used to improve the quality of individual monitoring in specific workplace fields for all dosimetry systems.

As specified in ISO 21909-1, the Individual Monitoring Service (IMS) shall specify clearly in its documentation the energy range (as described in ISO 21909-1) for which the dosemeter is qualified.

This document provides methodology and criteria to qualify the dosimetry system at workplaces where it is used. The criteria in this document apply to dosimetry systems which do not meet the criteria with regard to energy and direction dependent responses described in ISO 21909-1. That means that this document shall be systematically used to qualify at workplaces a dosimetry system that does not fulfil the criteria of ISO 21909-1 on the dependence of the response on neutron energy and direction of incidence.

The qualification of the dosimetry system at workplace aims to demonstrate that:

• either, the non-compliance of the dosimetry system to some of the requirements on the energy or direction dependent responses defined in ISO 21909-1 will not lead to significant discrepancies in the dose determination for a certain workplace field;

• or, that the correction factor or function used for this specific studied workplace enables the dosimetry system to accurately determine the conventional dose value with uncertainties similar to the ones given in ISO 21909-1.

Methodologies to characterize the workplace field are also described in the normative annex A, to help performing the qualification of the dosimetry system.

This document is directed at all stakeholders who are involved: IMSs, accreditation or regulatory bodies, and users of the particular dosimetry systems (the user is meant as the entity which assigns the dosimetry system to the radiation worker and records the assigned dose.)

The provider of the dosimetry system shall provide the type test results corresponding to ISO 21909-1. However, in the case when the dosimetry system to qualify will not comply with all the criteria of ISO 21909-1 dealing with the energy and angle dependence of the response, some tests of the ISO 21909-1 can be not performed. In that case, the requirements in accordance of the part 2 (see 6.3) shall be fulfilled instead.

This document only addresses neutron personal monitoring and not neutron criticality accident conditions.