核电厂超设计基准事故下热交换器的密封结构设计及分析方法

Sealing structure design and analysis method of heat exchanger under beyond-design basis accident in nuclear power plant

核电厂中,需要考虑正常运行工况、预计运行工况、设计基准事故以及超设计基准事故等。对于正常运行工况、预计运行工况以及设计基准事故,采用保守的方法进行工程设计,但对于超设计基准事故,其发生的概率很低,根据纵深防御原则,需要对相关设备进行适宜地设计和分析。超设计基准事故研究是个前沿的课题,缺乏相关设计经验和分析评定准则。以三代核电站中的余热排出热交换器为例,提出了该热交换器在超设计基准事故下的密封结构优化设计方案以及相应的密封性能及结构完整性分析评定方法,研究结果为超设计基准事故下的设计和分析提供了参考。

In nuclear power plants,normal operating conditions,expected operating conditions,design basis accident and beyond-design basis accident need to be considered.For normal and expected operating conditions and design basis accident,conservative method is adopted for engineering design.However,for beyond-design basis accident,its the probability is very low,and according to the defense-in-depth principle,it is necessary to conduct appropriate design and analysis for relevant equipment.The beyond-design basis accident research is a cutting-edge subject,there is a lack of relevant design experience and analysis evaluation criteria.Taking the residual heat removal exchanger as an example,the optimization design scheme of the sealing structure of the heat exchanger and the sealing performance and structure integrity analysis and assessment methods under beyond-design basis accident were proposed.The research results provide a reference for the follow-up engineering design and analysis under the beyond-design basis accident.