含氢反射层对金属活性区快中子脉冲反应堆特性参数的影响

Effect of Hydrogenous Reflectors on Characteristic Parametersof Fast Burst Reactors With Metal Active Zone

基于点堆动力学模型,分析了金属活性区快中子脉冲反应堆的脉冲特性,给出了不同样品条件下含氢系统CFBR-Ⅱ堆的裂变脉冲参数,分析了含氢反射层对金属活性区快中子脉冲反应堆特性参数的影响。实验结果表明,布置含氢材料样品后会显著改变CFBR-Ⅱ堆的裂变脉冲特性:在相同的反应性条件下,缓发临界时瞬发中子衰减常数和脉冲峰裂变率明显变小,脉冲宽度变宽;受周围样品的影响,在不同的反射层状态下脉冲裂变数与反应性关系并不相同;含氢反射层系统的反应性反馈系数大于纯金属铀活性区的反应性反馈系数;当反射层的贡献更大时,点堆模型将不再适用。

The characteristic parameters of fast burst reactors with metal active zone is analyzed based on a point reactor kinetics model.The fission burst parameters is obtained in CFBR-Ⅱequipped with several different hydrogenous reflector samples.The effect of hydrogenous reflectors on these parameters is analyzed.It is found that hydrogenous reflectors obviously changed fission burst characteristics of CFBR-Ⅱrelative to the system without reflector.The prompt neutron decay constant at delayed critical and the fission rate peak become smaller,and the width of burst becomes wider in hydrogenous reflector system with the same reactivity.Under the influence of the surrounding samples,the relationship between fission yield and reactivity is different at different reflector states.The reactivity feedback coefficient of the hydrogenous reflector system is greater than that of the pure uranium active zone.If the reflector contribution to reactivity is large enough,the reactor kinetics model will be no longer suitable.