原型微堆低浓化初步研究

Primary Research for Conversion of Prototype Miniature Neutron Source Reactor With Low Enrichment Uranium

利用蒙特卡罗计算程序,对高浓铀为燃料的原型微堆的有效增殖因数、控制棒价值、上铍反射层价值以及辐照座内的中子注量率等参数进行了计算。将计算值与实验结果进行了比较,两者基本相符。在原型微堆堆芯尺寸保持不变的情况下,将堆芯燃料元件芯体用富集度为12.5%UO2替换UAl和用锆包壳替换铝包壳,对堆芯燃料低浓化方案进行了计算,给出了方案的计算结果。并利用RELAP5程序计算了原型微堆低浓铀堆芯阶跃引入4.0mk反应性情况下反应堆的相关参数。

The parameters of prototype miniature neutron source reactor（MNSR） with high enrichment uranium（HEU）,such as keff,worth of the central control rod,worth of top beryllium reflector and the neutron flux density,were calculated using the Monte-Carlo code.The comparison was made between the calculated results and the experimental results,and they fit with each other very well.Without changing the core dimensions of the prototype MNSR,but substituting the HEU fuel with LEU fuel of UO2 with 12.5% enrichment and Al cladding with zircaloy cladding,keff,worth of the central control rod and neutron flux density were calculated again,and thermal dynamic features of releasing 4.0 mk excess reactivity were analyzed using RELAP5 code.