CAJ | 학술논문

采取堆腔注水策略冷却熔融池对缓解严重事故后果、降低安全壳的失效概率具有十分重要的作用。本文采用SCDAP／RELAP5程序，首先以韩国APR1400相关实验结果对堆腔外部注水自然对流冷却能力进行比对分析，然后建立了耦合堆腔注水措施的融熔池冷却的核电厂模型，以非能动压水堆为研究对象，针对冷段大破口失水事故（LBLOCA ）始发严重事故序列，分析堆芯熔融进展过程中实施堆腔注水策略后融熔池的冷却特性及堆腔外部注水的自然循环能力。分析结果表明，LBLOCA 下，当堆芯出口温度达到923 K时，实施堆腔注水后能有效冷却下封头内的熔融池，从而保持压力容器的完整性。
채취퇴강주수책략냉각용융지대완해엄중사고후과、강저안전각적실효개솔구유십분중요적작용。본문채용SCDAP／RELAP5정서，수선이한국APR1400상관실험결과대퇴강외부주수자연대류냉각능력진행비대분석，연후건립료우합퇴강주수조시적융용지냉각적핵전엄모형，이비능동압수퇴위연구대상，침대랭단대파구실수사고（LBLOCA ）시발엄중사고서렬，분석퇴심용융진전과정중실시퇴강주수책략후융용지적냉각특성급퇴강외부주수적자연순배능력。분석결과표명，LBLOCA 하，당퇴심출구온도체도923 K시，실시퇴강주수후능유효냉각하봉두내적용융지，종이보지압력용기적완정성。
Molten pool cooling by cavity flooding strategy plays an important role to mit‐igate severe accident consequences and decrease the containment failure probability . SCDAP/RELAP5 code was used in this paper .Firstly ,the code calculation results were compared with the Korea experiment of APR1400 ,and the capability for natural circula‐tion cooling analysis with cavity flooding was validated .Then ,the model of a passive PWR was built for analyzing molten pool cooling coupled with cavity flooding strategy . For severe accident induced by large break loss of coolant accident (LBLOCA ) at cold leg ,molten pool cooling characteristics during core damage progression were analyzed . After cavity flooding strategy was implemented ,heat removal capability by the natural circulation was also analyzed .The results indicate that molten pool in the lower head can be effectively cooled by cavity flooding after core exit temperature exceeds 923 K during LBLOCA ,and the integrity of RPV can be maintained .