Analyses and solutions for the inlet pipeline crack of primary system pipe dead end check valve of Qinshan nuclear power plant

A number of pipe dead ends exist in the primary system of nuclear power plants, pipe dead end equipments and pipelines easy to produce defects that seriously affect the safety of system operation, analysis and solution researching for this problem is an important work of plants aging management. There is a typical pipe dead end in the primary system of hot injection pipeline in Qinshan nuclear power plant, the defects of check valve internal leakage and inlet pipeline cracks are bring forward as example to analyze the steam interspaces producing principles, influence to the SCC corrosion of materials, and the solutions that replacing partial pipeline based on the aging management was proposed with some reference for the further researching of pipe dead end and replacing work of the main loop pressure boundary equipment. (authors)