热管冷却双模式空间堆堆芯瞬态安全特性分析

为研究热管冷却双模式空间堆(HP-BSNR)概念设计的可行性和推进模式下堆芯瞬态安全特性,本文基于堆芯结构和稳态程序计算的初始参数分布,建立了堆芯数学物理模型,并开发了适用于HP-BSNR的瞬态安全分析程序TTHA_HPBSNR,计算了HP-BSNR在推进模式下反应性引入和堆芯失流等不同瞬态事故工况下的安全特性,同时分析了反应堆关键参数对HP-BSNR堆芯瞬态安全特性的影响。结果表明,由于堆芯固有负反馈机制的作用,发生反应性引入事故时,堆芯功率最终达到一新的稳定值,且燃料最高温度并未超出安全限值。而发生失流事故时,反应堆能实现自动停堆,且负反馈系数的大小决定了自动停堆的响应时间。相较于反应性引入事故,失流事故对HP-BSNR的安全运行威胁更大。

Transient-state Safety Characteristic Analysis of Bimodal Space Reactor with Heat Pipe

In order to deeply study the feasibility and transient-state safety characteristic under propulsion mode of bimodal space reactor with heat pipe (HP-BSNR) proposed in this paper, the mathematics model was established based on the preliminary reactor system parameters obtained from steady-state code and the simplified structure of reactor core. Then a transient-state safety analysis code TTHA_HPBSNR for HP-BSNR was also developed. With the developed transient-state safety analysis code, typical transient accident conditions in HP-BSNR including reactivity insertion and loss of propellant were analyzed. And the influence of reactor core key parameters on the transient-state safety characteristic was also studied. The results show that the core power can reach a new steady state under the condition of reactivity insertion accident and the maximum fuel temperature does not exceed the safety limitation because of the negative feedback mechanism. Besides, under the condition of losing propellant, HP-BSNR can shut down automatically depending on the negative feedback mechanism and the value of negative feedback coefficient determines the response time of automatic shutdown. In conclusion, compared with the reactivity insertion accident, the accident of losing propellant has a larger threat to HP-BSNR safety operation.