Optimization of radiation protection at the NPP unit decommissioning stage

The results of activities by JSC Concern Rosenergoatom, the operating organization, for introducing and optimizing radiation protection at NPPs are shown. Requirements to establishing the NPP decommissioning database are presented and the importance of its role in minimizing the personnel radiation exposure is shown. Ways are presented for implementing the principle of the NPP decommissioning radiation protection optimization. Components of the automated data processing subsystem for unscheduled measurements of radiological environment (ADPS UM RE) introduced as part of Beloyarsk NPP's phase I units under the Program for Optimizing the Radiation Protection of Personnel at Nuclear Power Plants in Russia are described. A description of unscheduled measurements and respective measurement points is provided. Major sources of ionizing radiation at shut down NPP units are listed. The key functions of the ADPS UM RE are described (determination of inspection points and the radiation supervisor movement route during measurements, input and databasing of measurement results, methods for visualizing information on the parameters that characterize the radiological state of monitored items, protection of information against unauthorized access). Possible ways are shown for minimizing the personnel radiation exposure in the process of instrument-based measurements, sample taking and sample analysis (optimization of the movement route between inspection points, selection of measuring devices, analysis of earlier measurements, etc.). Requirements are presented to the selection of measurable radiation parameters for the particular facility. Information is presented on joint studies conducted by experts at Ural Federal University, Beloyarsk NPP, and the Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences to develop the algorithm of optimizing the radiation supervisor movement routes considering the need for avoiding the obstacles with visiting the predetermined points (the radiation supervisor mission), and virtual models of radiation-hazardous rooms. The results of these studies will make it possible (using the database formed as part of the ADPS UM RE) to automate generation of the best possible radiation supervisor route, description of tasks for measuring the radiation environment parameters, and, accordingly, minimization of the radiation supervisor exposure doses. © 2019 Obninsk Institute for Nuclear Power Engineering, National Research Nuclear University 'MEPhI'. All rights reserved