先进非能动压水堆设计采用自动卸压系统（ADS ）对一回路进行卸压，严重事故下主控室可手动开启ADS ，缓解高压熔堆风险。然而ADS的设计特点可能导致氢气在局部隔间积聚，带来局部氢气风险。本文基于氢气负面效应考虑，对利用ADS进行一回路卸压的策略进行研究，为严重事故管理提供技术支持。选取全厂断电始发的典型高压熔堆严重事故序列，利用一体化事故分析程序，评估手动开启第1～4级ADS、手动开启第1～3级ADS、手动开启第4级ADS 3种方案的卸压效果，并分析一回路卸压对安全壳局部隔间的氢气负面影响。研究结果表明，3种卸压方案均能有效降低一回路压力。但在氢气点火器不可用时，开启第1～3级ADS以及开启第1～4级ADS卸压会引起内置换料水箱隔间氢气浓度迅速增加，可能导致局部氢气燃爆。因此，基于氢气风险考虑，建议在实施严重事故管理导则一回路卸压策略时优先考虑采用第4级ADS进行一回路卸压。%For advanced passive pressurized water reactor ,the automatic depressuriza‐tion system (ADS ) can be applied to depressurize the reactor coolant system (RCS ) . T he main control room can manually open ADS to mitigate the risk of overpressure dur‐ing severe accidents .However ,the design characteristics of ADS may cause hydrogen releasing into the containment .Accumulating in the containment may cause hydrogen hazard in containment .Against this background ,the RCS depressurization strategy in severe accidents was analyzed and its negative impact standing from hydrogen risk to make suggestion to severe accident management was evaluated .The station black out accident was selected and analyzed with integral severe accident analysis code .Three different depressurization schemes were discussed on both depressurization effect and hydrogen risk .The hydrogen distribution and risk in different compartments were cal‐culated through severe accident analysis .The results show that all three schemes ana‐lyzed in this paper can depressurize the RCS effectively .However ,opening ADS stage 1‐3 causes immediate increase of hydrogen concentration in in‐containment refueling tank compartment if hydrogen igniters are unavailable and can cause hydrogen explosion that threatens containment integration .As a result ,the suggestion is made for severe acci‐dent management guideline w hich gives priority to ADS stage 4 w hen implementing RCS depressurization .
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