Preliminary analysis of typical accidents of CFETR helium-cooled solid breeder blanket system based on COSINE

Abstract Blankets are an important component of fusion reactors and the key object of thermal design and safety analysis. The helium-cooled solid breeder (HCSB) blanket is one of the three candidate tritium breeding blanket concepts for the Chinese Fusion Engineering Test Reactor (CFETR). Fusion reactors’ thermal design and safety analysis are mostly based on fission reactor procedures worldwide. In this paper, based on the system safety analysis module cosSyst in the COSINE code package of China’s independently developed system safety analysis code for pressurized water reactors, functional development was carried out for the helium-cooled blanket of fusion reactor, and helium physical property envelope and corresponding heat transfer model were added. The modified code was used to analyze three typical accidents with the blanket and the combined helium cooling system (HCS): In-Vessel LOCA, In-Box LOCA, and Ex-Vessel LOCA. The research findings indicate that under the three accident scenarios, the first wall and the cooling loop system maintained their structural integrity, with no melting or exceeding pressure limits.