钠冷快堆瞬态热工水力及安全分析程序开发

钠冷快堆是第4代核反应堆的主力堆型，瞬态热工水力及安全特性是其设计研发和安全评审的重要工作，需要专用的分析工具。本文基于模块化建模思想，建立了钠冷快堆系统关键部件的热工水力模型和辅助模型，采用具有高稳定性和自动变步长能力的Gear算法，开发了钠冷快堆瞬态热工水力及安全分析软件THACS，并通过了国际基准题EBR-Ⅱ的有保护失流事故实验SHRT-17的初步验证。结果表明，THACS程序能较好模拟此实验的瞬态过程，具备钠冷快堆瞬态热工水力及安全分析的能力，可为我国钠冷快堆研发提供支持。

Code Development for Transient Thermal-hydraulics and Safety Analysis of Sodium-cooled Fast Reactor

Sodium-cooled fast reactor is one of the Generation-Ⅳ nuclear reactors. Research on its transient thermal-hydraulic and safety characteristics is the significant work for its design and licensing, which requires specific analysis tools. Based on the modular modeling idea, the thermal-hydraulic models and auxiliary models were established for the key components of the sodium-cooled fast reactor system. The Gear algorithm with high stability and automatic step-changing capacity was adopted to develop the transient thermal-hydraulic analysis code for sodium-cooled fast reactors (THACS), which was validated by the protected loss-of-flow test SHRT-17 of the international benchmark EBR-Ⅱ. The results show that THACS can simulate the test transient process well, which indicates that THACS code has possessed the capability to perform the transient thermal-hydraulics and safety analysis for sodium-cooled fast reactor, and support the development of China sodium-cooled fast reactor.