钼铼合金对掉落临界安全的影响

发射阶段的掉落临界安全是空间快堆设计中的重点和难点。目前空间快堆保证掉落临界安全的常用手段之一是采用谱移材料兼作结构材料。钼铼（Mo-Re）合金因其优异的谱移性能和高温性能常用作空间快堆的谱移材料和结构材料。本文以美国Prometheus基本型堆芯方案为研究对象，采用MCNP程序计算并分析了不同Re含量的Mo-Re合金对掉落临界安全的影响及其机理。计算结果及分析表明：Re含量不同，反应堆掉落工况对临界安全影响也不同；能谱软化和Re含量增加引起的Re共振吸收增强是最严重掉落工况转变的主要因素。

Effect of Mo-Re Alloy on Drop Critical Safety

T he drop critical safety at the launch phase is the key point and difficult point in the design of space fast reactor .One of the general methods to ensure drop critical safety is using spectral shift absorption material as the structure material .The Mo‐Re alloy is usually used as spectral shift absorption material and the structure material with its excellent spectral shift performance and high temperature performance .The study was focused on Prometheus basic core scheme ,using MCNP code ,calculated and ana‐lyzed the effect of M o‐Re alloy on drop critical safety and its mechanism in the different drop conditions .T he results suggest that the drop condition has different effects on the critical safety with the different contents of Re .The strengthened resonance absorption caused by softenspectrum and the increase of Re content are the main factors of the change of the worst drop condition .