模拟脉冲源方法计算CFBR-Ⅱ堆缓发临界瞬发中子衰减常数

Calculation of CFBR-Ⅱ’s Prompt Neutron Decay Constant at Delayed Criticality by the Simulated Burst-Neutron Method

通过计算国外基准装置缓发临界处的瞬发中子衰减常数,证明了用模拟脉冲源方法计算出的瞬发中子衰减常数是可信的。用该方法计算了CFBR-Ⅱ堆5个次临界状态的瞬发中子衰减常数;线性外推得到缓发临界时系统的瞬发中子衰减常数为0.55μs-1;计算值与试验结果相比存在着偏差。文中简单分析了产生偏差的原因。

By calculating foreign benchmark assemblies prompt neutron decay constants at delayed criticality, it is proved that the results calculated is faithful by using the simulated burst-neutron method. CFBR-Ⅱ’s prompt neutron decay constants are calculated with the method at five subcritical states. The prompt neutron decay constant attained at delayed criticality is 0.55μs-1by linear extrapolation.There are difference between calculational result and the experimental result. The article simply analyses reasons for the difference.