Development of Risk Informed Aging Management Program in Decommissioning

Abstract

This paper proposes to solve the issues related to aging management program (AMP) during the decommissioning phase by using risk information. The AMP for the decommissioning plants has not been established while the number of permanently shut down and decommissioned nuclear power plants are increasing in the world. The first issue is the change of the functional importance of the safety systems at the beginning of decommissioning. We propose to evaluate the importance using the probabilistic risk assessment (PRA) model with the change of specification in the decommissioning plant and to determine new importance grade. The second issue is to make the maintenance based on the appropriate risk information. This risk information should be based on the progress of decommissioning, reflected and evaluated in the PRA model, as well as information obtained from maintenance inspections, including the ROP process, and failure experience during routine operation. To address these issues, the maintenance program in decommissioning that uses the evaluation of risk information according to the decommissioning phase is proposed in this paper.