SPACE-R 意外掉落事故的临界安全分析

摘要

当空间热离子反应堆发生意外掉落事故时，必须采取反应性控制措施保证反应堆处于次临界状态。SPACE‐R 是设计目标为40 kWe 、10 a 寿命的空间核反应堆。适合 SPACE‐R 意外掉落事故的反应性控制方案有：在燃料空腔内加入控制材料及在慢化剂中放入可燃毒物棒。利用MCNP程序分别对两种方案下反应堆的反应性进行计算，可知两种方案均对 SPACE‐R 在意外掉落事故下的反应性有一定的改善。经综合考虑得出一个最终设计方案，能满足意外掉落事故的临界安全验收准则。%When a space thermionic reactor is in an unexpected dropping accident ,reac‐tivity control measures must be taken to ensure the reactor is in the subcritical state . SPACE‐R which is designed for 40 kWe ,and 10 years of life is used for supplying space electric power . There are two control measures which are proper for unexpected dropping accident of SPACE‐R :Adding neutron absorber in the fuel cavity and adding burnable poison robs in the moderator .By calculating reactivity of SPACE‐R using MCNP code , there is a conclusion : The two measures are all useful for controlling reactivity of SPACE‐R in the unexpected dropping accident .Furthermore ,there is a final design scheme which meets the critical safety criteria for the unexpected dropping accident .