Design Improvement and Open Item Analysis of Containment Sump Strainer in QINSHAN Phase II Extension Project

Considering the disadvantage of the small filter area and insufficient filter capacity of the conditional design sump strainers, China National Nuclear Safety Administration has raised the new surveillance requirement for the design and corresponding analysis of sump strainer to ensure the safety function. This paper discusses the clogging and design improvement of the sump strainer in Qinshan Nuclear Power Plant Phase II Extension Project and analyzes the consistency between the design of sump strainers and the requirement of RG 1.82. The open item of the sump strainer has also been discussed.