Methodological Approaches to Establishment of Class of Work with Open Sources of Ionizing Radiation

One of the requirements of the current Basic Sanitary Rules for Radiation Safety (OSPORB-99/2010) for the organization of work with open sources of radiation (radioactive materials) is the establishment of class of work that determines the zonality of industrial premises, requirements for their decoration, layout of technological equipment, ventilation, using of personal protective equipment, etc. Formalization of such requirements is necessary as in the design of enterprises, as well as for the organization safety working conditions for personnel in existing production facilities. The accumulated long-term experience of the country’s nuclear industry has shown the validity of the requirements imposed by the existing regulatory documents for the organization of work with open nuclides at the initial stage оrganisation of large-scale production. In article presents methodological approaches to the procedure for establishing class of work as at the projected enterprises of the nuclear industry and when adjusting the established classes of work at existing enterprises. Substantiated approaches to determining the value of the minimum significant activity of a radionuclide based on data on its radiotoxicity under internal irradiation (with inhalation intake), as required according to OSPORB-99/2010. In article proposed new values of the minimum significant activity for a number of radionuclides. Unified classes of work are recommended for individual sections of separation and sublimate uranium production. The procedure for determining the actual total activity at the workplaces of uranium production is described, taking into account data on the contamination of work surfaces and the volumetric activity of uranium aerosols in the air of the working area. These methodological approaches were implemented in the Guidelines of MU 2.6.1.02-03 “Establishment of class of work with open radionuclide sources in the handling of uranium and its compounds at the enterprises of JSC “TVEL”, in the Guidelines of MU 2.6.1. 044-08 “Establishment of class of work when dealing with open sources of radiation” as well as in the draft updated Guidelines for establishing the class of work when working with open sources of ionizing radiation, developed in 2024.