New Types of Reference Materials in the Field of Ionizing Radiation Measurements

In the Russian Federation, obligations to comply with radiation safety apply to all legal entities and individuals whose activities may result in the irradiation of people and the environment. Protection from dangerous ionizing radiation is a combination of legislative, economic and engineering measures. Part of this system is metrological support for the activities of economic entities. The State Verification Schedule for means measuring radionuclide activity flux and flux density of alfa-, beta-particles and photons of radionuclide source has undergone a number of changes. In particular, it establishes the role of reference materials as one of the main means of transferring units of specific activity and activity of radionuclides from the State Primary Standard for the units of radionuclide activity, specific activity of radionuclides, flux of alpha, beta particles and photons of radionuclide sources GET 6–2016 to working standards and measuring instruments. The changes introduced into the State Verification Schedule require the development of new types of reference materials in the field of ionizing radiation. This article raises the main issues of development and approval of reference materials of radionuclide activity based on a mixture of radionuclide solutions and a liquid scintillator. A detailed explanation of the choice of radionuclides is presented, a brief description of the characterization method is given, and metrological characteristics of the developed reference materials are described. The reference materials developed and described in this article act as a new type of working standards in accordance with GOST 8.033-2023. The authors outlined a concept for the further development and application of new types of reference materials in the field of measuring the activity and specific activity of alpha- and beta-emitting radionuclides. The new types of reference materials described in the article will fully cover the need for means of verifying devices whose operating principle is based on detecting ionizing radiation using a liquid scintillator.