CAP1000氢气缓解的设计分析和研究

Design Analysis and Study on CAP1000 Hydrogen Mitigation

在严重事故下,堆芯燃料棒锆包壳与水蒸气反应产生大量氢气。如果发生压力容器失效,堆芯熔融物与混凝土相互作用,将产生额外的氢气以及一氧化碳等可燃气体。氢气释放到安全壳,达到一定浓度后可能发生燃烧、爆燃甚至爆炸,可能危及安全壳的完整性。本文梳理CAP1000氢气缓解措施设计现状,从序列分析和概率论角度探讨了缓解措施的有效性和可靠性,探索了可能的改进措施并进行效果分析,这些分析和研究有助于对氢气风险的全面理解。

Under severe accident condition, considerable amount of hydrogen would be produced when cladding reacts with steam. If reactor pressure vessel fails, the molten core would be discharged into the cavity. When the molten core reacts with concrete, additional burnable gases such as hydrogen and carbon monoxide would be produced. Hydrogen which is released into the containment may combust, deflagrate and even detonate when concentration reachs certain limit. These phenomena may endanger the containment integrity. Curent CAP1000 hydrogen mitigation measurements are summarized. Effectiveness and reliability of mitigation measurements were discussed in the perspective of sequence analysis and PSA analysis. Potential improvement was proposed and evaluated. All these analysis and study contributed to comprehensive understanding on hydrogen risk.