安全壳过滤排放系统长期运行热工水力特性分析

安全壳过滤排放系统（FCVS）的长期运行特性对缓解严重事故具有重要作用。为探究采取周期性启闭排放策略时FCVS的长期运行热工水力特性，使用热工水力程序RELAP5对假想严重事故工况下特定的FCVS进行建模，并进一步对初始液位、环境温度、衰变热功率对洗涤液储量的影响进行敏感性研究。结果表明在假想事故序列下，该FCVS可实现稳定的周期性启闭运行达250 h；通过敏感性分析发现为保证FCVS的正常运行，需要根据环境温度适当调整初始液位，并控制衰变热功率在一定范围内。本文的研究可为FCVS的运行和优化及核电厂安全分析提供一定指导。 

Thermal-Hydraulic Characteristics of Filtered Containment Venting System for Long-Term Operation

Long-term operation characteristics of the filtered containment venting system (FCVS) is important for mitigating the severe accident. To research the long-term thermal-hydraulic characteristics of FCVS with periodically open-and-close-venting strategy, a typical FCVS under assumed severe accident was simulated by using the thermal-hydraulic code RELAP5. Further, the effects of initial fluid level, environment temperature and decay heat power on the operation characteristics were researched by sensitivity analysis. The results show that the FCVS can achieve stably the periodic operation up to 250 hours under the assumed accident. By sensitivity analysis, it is found that in order to ensure the normal operation of FCVS, the initial fluid level should be changed with different environment temperature, and the decay heat power should be controlled within a certain range. This research may provide guides for the operation and optimization of FCVS and the safety analysis of nuclear power plants.