Spent fuel pool transient analysis under accident case and the flow establishment process of passive cooling system

Spent fuel pool is one of the important auxiliary equipments for nuclear reactor. In this paper, RELAP5 code was used as the research tool and the Daya Bay spent fuel pool was chosen as the analysis object. By the establishment of corresponding nodalizations, the paper eventually calculated the time spent fuel pool needed to reach boiling from steady state and the time to make water level falling until the exposure of spent fuel after the outside main cooling system was failure. Furthermore, the paper has also discussed the passive cooling system for spent fuel pool, and then an establishment program of outside passive cooling system after main cooling system´s failure was proposed. The results showed that: when the main cooling system is failure, it would take a relative long time to make the pool water reach boiling from steady state. During that time, if some certain remedial measures are adopted, it will not result in spent fuel pool serious accident. And the calculation results of this paper can be the certain reference for spent fuel pool engineering design.