Thermal-hydraulic design and transient analysis of passive air cooling system for CPR1000 spent fuel storage pool

After the Fukushima nuclear accident in 2011, the safety of the spent fuel pool (SFP) which lost the cooling function and feed water suffered an unprecedenled threat. Many countries paid attention to the safety of the SFP. Researches on improving the safety of the SFP have become the important topic. In China analyzing and improving the safety of the SFP forCPRIOOO is one sub-topic of them. This paper gives a design of passive air cooling system for CPRI01XI SFP. which can control the water temperature of the SFP under 80°C. Then the transient analysis of the CPRIOOO SFP with designed passive air cooling system will be done in statio n black out (SB O) accident by the best-estimate thermal-hydraulic system code RF.I.AP5. The design calculation results show that to maintain the temperature of CPRIOOO SFP under H0°C. the tube numbers of the SF P and air heat ex changers are 6627 and 19086 respectively. The height difference between the bottom of the air heat ex changer and the top of the SF P heat exchanger is 3.8m The SFP heat ex changer's tube number decreases as the height difference increases, while the air h cat exchanger's tube number increases. The transient analysis results show that after the SBO accident, a stable air cooling natural circulation is established The surface temperature of CPRIOOO SFP increases continually until 80.5°C. which indicates that the design of the passive air cooling system for CPRIOOO SFP is capable of re moving the decay heat to maintain the temperature of the SFP around 80°C after losing the heat sink.