GOTHIC局部氢气风险三维分析研究

Study on Local Three Dimension Hydrogen Risk Using GOTHIC

目前的氢气风险分析中,主要采用一体化严重事故分析程序进行分析计算。日本福岛事故后,对氢气风险分析提出了更高的要求。为了实现对集总参数程序的有益补充,本文开展了GOTHIC程序氢气风险三维分析的研究。利用GOTHIC建立了局部氢气风险三维分析模型,在模型验证的基础之上,对典型严重事故序列下的氢气风险进行三维分析研究。研究表明:安全壳上部空间气流混合较好,氢气分层并不是非常明显;对于核电厂压力容器直接注射(DVI)管道破口所在的非能动堆芯冷却系统隔间B(PXS-B),由于破口以下部分区域被水淹没,破口以上区域的氢气浓度较高,但氢气风险较小。

Integrated severe accident code is used to analyze the hydrogen risk in current safety assessment.After Fukushima accident,higher requirements are placed on hydrogen risk analysis.In order to supplement the lumped parameter analysis,three dimension hydrogen risk analysis method using GOTHIC is studied.Local three dimension hydrogen risk model is constructed by GOTHIC.Based on model validation,typical severe accident cases are chosen to analyze the hydrogen distribution.The results show that,hydrogen and other gas are mixed well in the upper compartment of the containment,and hydrogen stratification phenomenon is not obvious.For DVI rupture accident in PXS-B,the lower area of the break is flooded,and the hydrogen concentration for the upper area of the break is large,however,the hydrogen risk is little.