AP1000小破口事故下非能动氮气安注箱的瞬态特性研究

根据AP1000非能动氮气安全注入水箱的结构和工作原理建立了热工水力模型并开发了计算分析程序TACAP。利用TACAP计算得到了AP1000非能动氮气安全注入水箱在两种小破口失水事故（包括25.4 cm等效直径冷管破口和5.08 cm等效直径冷管破口）下的瞬态特性，得到了箱内水位及注入流量等关键参数的瞬态变化。计算结果表明：安注箱在小破口失水事故后能提供高效的安全注入，对一回路快速地进行冷却和降压，有效地缓解事故后果。TACAP计算结果与西屋公司NOTRUMP程序计算结果基本一致，表明了TACAP程序的适用性和正确性。

Study on Transient Characteristics of AP1000 Passive Nitrogen-Typed Accumulator During SBLOCA

Based on the basic principle and structure of passive nitrogen-typed accumulators, the thermal-hydraulic model was built up and the transient analysis code for accumulator of AP1000 (TACAP) was developed. In addition, the performance of the accumulators was analyzed during different cold leg small break loss of coolant accidents, including 25.4 cm equivalent diameter cold leg break and 5.08 cm equivalent diameter cold leg break. This study also brought about some key transient characteristics during these accidents, such as water level of tank and injection flow rate. The calculation result shows that the injection flow of accumulator can effectively lower temperature and reduce pressure of primary circuit. The calculation result of TACAP also shows good agreements with the calculation result performed by Westinghouse (USA) with NOTRUMP code, which demonstrates the applicability and the validity of TACAP.