Seismic Periodic Safety Review of Safety-related Equipment in Ulchin Nuclear Power Plant Units 1 and 2

PSR (Periodic Safety Review) is to determine, for an operating nuclear power plant, the extent to which the plant confirms to current standards and practices, the extent to which the licensing basis remains valid, the adequacy of the arrangements that are in place to maintain safety until the next PSR, and the safety improvements to be implemented to resolved the safety issues that have been identified. PSR process consists of comprehensive assessment including the review of seismic qualification. With the beginning of Kori 1 PSR on May 2001, half of all Korean operating NPPs carried out and is performing PSR, so lots of experiences were accumulated through PSR. In this paper, the assessment methods and results of seismic PSR in Ulchin 1 and 2 are introduced including safety improvements to enhance the safety. Also walk-down procedure and an evaluation sheet format is presented, which were established through this seismic PSR of Ulchin 1 and 2