严重事故下安全壳卸压箱隔间氢气浓度场模拟

Hydrogen Concentration Distribution Simulation During Severe Accidents in Pressurizer Relief Tank Compartment of NPP Containment

根据MELCOR程序对全厂断电诱发的严重事故下安全壳内各隔间的氢气浓度分布的计算结果,参考美国联邦法规关于氢气控制和风险分析的标准,分析安全壳内氢气的燃烧风险。结果表明:安全壳内平均氢气浓度不会导致整体性氢气燃烧,但存在局部燃烧的风险。通过CFD程序对氢气浓度较高的卸压箱隔间进行氢气释放和空间气体流动过程的模拟,得到更细致的卸压箱隔间内氢气浓度场分布,给出氢气聚集区域的准确位置,为采取严重事故缓解措施,设计氢复合器布置方案提供了参考依据。

Based on the analysis by MELCOR for hydrogen concentration distributions in compartments of NPP containment during severe accidents which is induced by station blackout, the hydrogen combustion risk was investigated. According to the hydrogen control and risk analysis standard of US, the results show that the average hydrogen concentration will not bring on global deflagration, but local deflagration may occur. By application of CFD code, further simulation of hydrogen release and flow process in pressurizer relief tank compartment was performed. More details of hydrogen distribution and hydrogen accumulation zone were showed. Through the results, some insights were given as references for severe accident mitigation measures and hydrogen recombines arrangement design.