Reliability evaluation study on sodium fire protection system of China experimental fast reactor

China Experimental Fast Reactor (CEFR) is the first sodium-cooled fast reactor of China, its safety has been of widespread concern. Sodium fire safety issues become the focus of the industry. Using the method of fault tree and event tree, this paper analyzes fire protection system and related systems reliability when the sodium fire accident occurred for primary circuit cold sink by combining sequence and consequences. The evaluation results show that: the reliability of Sodium fire extinguishing system of CEFR sodium room is very high. Based on the qualitative and quantitative analysis of systems and components of the important degree, further propose optimization suggestions and measures for weak areas of sodium fire system design. (authors)