先进非能动压水堆防火喷淋对严重事故的缓解作用研究

依据先进非能动压水堆的严重事故管理导则(SAMG),消防系统中的防火喷淋系统,尽管属于非安全相关的系统,仍可以作为严重事故缓解策略,在以下三个方面起到严重事故缓解的作用:减少放射性气溶胶的质量;安全壳降温降压;安全壳注水。因此本文利用一体化严重事故分析程序,选取典型事故序列,评估防火喷淋系统在严重事故中的三种缓解作用的有效性为防火喷淋在严重事故管理导则中的应用提供技术支持。分析结果表明,防火喷淋系统能够实现堆腔淹没,在一定时间内进行安全壳降压,以及减少安全壳中放射性气溶胶的含量的作用,但由于系统限制,防火喷淋进行堆腔淹没的流量不能满足安全限值,并且只能推迟而不能够避免安全壳的失效。防火喷淋系统对严重事故的缓解作用虽然是有限的,但可为其他相关系统或设备的修复提供一定时间。

Mitigation on Severe Accidents with Fire Spray System in Advanced Passive PWR

The fire spray system FSS) of the Advanced Passive PWR as a part of the fire protection system can provide a non-safety related containment spraying function for severe accident mitigation which is included in the Severe Accident Management Guidelines (SAMG) of the Advanced Passive PWR.The effectiveness of the FSS is investigated on three effects for severe accident mitigation which are injecting into the containment,controlling the containment condition,and washing out fission product through three representative severe accident scenarios analysis with integral accident analysis code.Results show that the FSS can be effective for injecting into the containment,controlling the containment condition for a short term,and washing out fission product.However the FSS has its limitation:the flow rate of FSS cannot reach the safety criterion for cavity flooding,and containment failure can only be postponed but not avoided.Despite its limitation,the FSS can be effective as an alternative severe accident mitigation measurement for postponing the process of accidents for safety system recovery.