Assessment and Control Value Formulation on Radiological Consequence of On-Site Worker due to Radioactive Component Failure for Pressurized Water Reactor Plant

Abstract

All Structures, Systems, and Components (SSCs) in a nuclear power plant need to be classified according to their importance to safety to protect people and the environment. The Specific Safety Guide, No. SSG-30, issued by IAEA, guides how to meet the requirements for identifying safety functions and classification of SSCs and ensuring their appropriate quality and reliability. However, the relevant guidance has not specified the perspectives of low radiological consequences on on-site workers. To refine the SSCs classification and complement the IAEA guidance, a proposed limiting value and corresponding assessment method for low radiological consequence caused by SSCs failure from the on-site workers’ perspective based on international good practices are developed, which include the main process of on-site radiological consequence evaluation, the calculation method for different exposure pathways and the assessment assumptions. Also, typical examples of SSCs failure are also assessed to validate the proposed method’s feasibility. The assessment results show that the activity concentration of failure SSCs, the workers’ locations, the exposure duration of workers, and the local dose rate of each location are the main factors for on-site radiological consequence evaluation, and the proposed method in this paper can assist in the safety classification of SSCs in the third generation of pressurized water reactor nuclear power plants.