先进压水堆大破口始发严重事故下安全壳内氢气风险分析

本文采用集总参数法,在先进非能动压水堆核电厂严重事故一体化分析模型基础上,考虑先进压水堆非能动安全特性以及严重事故下采取熔融物堆内滞留(IVR)措施等特性对氢气风险的影响,开展了典型严重事故下安全壳内氢气风险分析。分别选取了冷段双端剪切断裂大破口、冷段大破口叠加IRWST重力注水有效以及ADS-4误启动三个典型大破口失水事故序列,对事故进程中的氧化温度、产氢速率以及产氢质量等特性进行了研究。选取产氢量最大的冷段大破口叠加IRWST重力注水有效事故序列,分析了氢气点火器系统的消氢效果。结果表明,堆芯再淹没过程产生大量氢气,采用点火器可有效去除安全壳内的氢气,从而降低氢气燃爆风险。

Hydrogen Risk Analysis for Advanced PWR Under Typical Severe Accidents Induced by LB-LOCA

With the lumped parameter method,considering the effects on hydrogen source and hydrogen risk induced by the passive safety characteristics and In-vessel Retention (IVR) of advanced PWR,the hydrogen risk analysis in the containment for advanced PWR is investigated. Large break loss-of-coolant accident(LB-LOCA) of cold-leg with IRWST inj ection failure,LB-LOCA with IRWST inj ection availability and ADS-4 spuriously open are chosen as the typical severe accident sequences to analyze the oxidizing temperature, hydrogen generation rate and total amount of hydrogen generated during the accident process. On the basis of hydrogen generation and concentration distribution,LB-LOCA with IRWST inj ection availability is screened out to analyze hydrogen removal capacity with igniters. The results show that reflooding process has a great contribution to the hydrogen production,and a certain number of hydrogen igniters could remove hydrogen effectively, to reduce the risk of hydrogen detonation of advanced PWR.