Hydrogen Risk Analysis and Strategy Research for Spent Fuel Pool

The problem of insufficient safety analysis for spent fuel pool was exposed after Fukushima accident, especially the lack of hydrogen risk analysis. According to the requirement of IAEA and HAD code, the hydrogen risk of spent fuel pool after severe accidents should be evaluated and the strategy of elimination of hydrogen risk should be analyzed. In this work, the MELCOR code was used to simulate the analyzing model, calculate the sequence of the severe accident in spent fuel pool and the generation and distribution of hydrogen, evaluate the hydrogen risk and analyze the mitigating measures of hydrogen risk. The results show that the hydrogen risk exists. The analysis of mitigating measures for hydrogen risk, which includes water injection, spray, ventilation and hydrogen recombiners, indicates that the water injection and spray can eliminate hydrogen risk, but the ventilation and hydrogen recombiners can’t eliminate hydrogen risk entirely. Thus, the eliminating hydrogen risk of spent fuel pool after severe accidents should lay emphasis on the effective make-up water, which can be realized by improving the reliability of make-up water and preventing the leakage of spent fuel pool.