Neutron ambient dose équivalent rate meters - Expérience in developing and using IEC 61005

Miroslav Voytchev (1) , Radoslav Radev (2)

1 IRSN/PSN-RES/SCA/LPMA - Laboratoire de physique et de métrologie des aérosols
2 LLNL - Lawrence Livermore National Laboratory

Measurements of neutron dose equivalent rates are challenging because there are no “perfect” instruments that cover the entire 9 orders of magnitude neutron energy range (thermal to 20 MeV). Hence quantifying the performance requirements in a standard for such instruments presents unique challenges. The international standard IEC 61005 Ed. 3 concerning neutron ambient dose equivalent (rate) meters was developed by Sub-Committee 45B “Radiation Protection Instrumentation” of the International Electrotechnical Commission (IEC). It was published in 2014 while its European transposition EN 61005 was issued in 2017. The main characteristics of the standard are presented as well as issues during its development. Measurements of the neutron energy, fluence and dose equivalent rates are provided which illustrate the challenges of specifying the standard test requirements for neutron dose (rate) meters when they are tested against the standard. Testing according to IEC 61005 of a portable neutron survey rate meter is also discussed. This will include tests as: •constancy of the dose rate response; •variation of the response due to neutron energy; •variation of the response due to angle of incidence; •overload; •response time; •temperature shock; •protection against moisture and dust; •drop test; •vibration and mechanical shock test; •various electromagnetic tests. Recommendations for the standard revision that is planned to be started around 2021-2022 will be discussed too. Possible fusion with IEC 61322 Ed. 2 “Installed dose equivalent rate meters, warning assemblies and monitors for neutrons of energy from thermal to 20 MeV” is considered.

Domaines: Physique [physics]

Miroslav Voytchev, Radoslav Radev. Neutron ambient dose équivalent rate meters - Expérience in developing and using IEC 61005. ERPW 2022, European Radiation Protection Week, Oct 2022, Estoril, Portugal. ⟨irsn-03972125⟩