Radio-ecological characterization and radiological assessment in support of regulatory supervision of legacy sites in northwest Russia

• Characterization of sites for storage of spent fuel and radioactive waste in northwest Russia.
• Development of radio-ecological visualization and prognostic radiological assessment tools.
• Control of radiation exposure during hazardous operations.
• Application of these developments to support regulatory supervision of legacy sites.

The Norwegian Radiation Protection Authority has been implementing a regulatory cooperation program in the Russian Federation for over 10 years, as part of the Norwegian government's Plan of Action for enhancing nuclear and radiation safety in northwest Russia. The overall long-term objective has been the enhancement of safety culture and includes a special focus on regulatory supervision of nuclear legacy sites. The initial project outputs included appropriate regulatory threat assessments, to determine the hazardous situations and activities which are most in need of enhanced regulatory supervision. In turn, this has led to the development of new and updated norms and standards, and related regulatory procedures, necessary to address the often abnormal conditions at legacy sites.This paper presents the experience gained within the above program with regard to radio-ecological characterization of Sites of Temporary Storage for spent nuclear fuel and radioactive waste at Andreeva Bay and Gremikha in the Kola Peninsula in northwest Russia. Such characterization is necessary to support assessments of the current radiological situation and to support prospective assessments of its evolution. Both types of assessments contribute to regulatory supervision of the sites. Accordingly, they include assessments to support development of regulatory standards and guidance concerning: control of radiation exposures to workers during remediation operations; emergency preparedness and response; planned radionuclide releases to the environment; development of site restoration plans, and waste treatment and disposal. Examples of characterization work are presented which relate to terrestrial and marine environments at Andreeva Bay. The use of this data in assessments is illustrated by means of the visualization and assessment tool (DATAMAP) developed as part of the regulatory cooperation program, specifically to help control radiation exposure in operations and to support regulatory analysis of management options. For assessments of the current radiological situation, the types of data needed include information about the distribution of radionuclides in environmental media. For prognostic assessments, additional data are needed about the landscape features, on-shore and off-shore hydrology, geochemical properties of soils and sediments, and possible continuing source terms from continuing operations and on-site disposal. It is anticipated that shared international experience in legacy site characterization can be useful in the next steps. Although the output has been designed to support regulatory evaluation of these particular sites in northwest Russia, the methods and techniques are considered useful examples for application elsewhere, as well as providing relevant input to the International Atomic Energy Agency's international Working Forum for the Regulatory Supervision of Legacy Sites.