钍在轻水堆中利用的研究

RESEARCH OF THORIUM UTILIZATION IN LWRS

对钍－２３２在轻水堆中利用进行了研究。考虑到现行轻水堆改型的方便，以秦山核电厂反应堆参数为基础，只改变堆芯燃料组分，在可裂变材料总量不变的条件下，对不同钍－２３２装量进行了多方案研究。结果表明，由于钍－２３２吸收中子后的主要转换产物是铀－２３３，它在热堆中的η值比铀－２３５和钚－２３９的高，因此在同样初始过剩反应性情况下，随着钍－２３２装量的增大，燃耗的加深，堆内易裂变材料总生成量也随之增大，转换比提高，从而使堆芯寿期延长，节省了核燃料。可见钍是一种有前途的能源资源。此外必须指出，在所研究的参数条件下以钍－铀重量比０．２５为佳。

In this paper,the utilization of thorium in LWRs is studied.In order to retrofit the existingLWRs conveniently, all parameters used are based on Qinshan Nuclear Power Plant.On the con- dition that only fuel composition is changed and total quantum of fissionable materials is constant,a lot of schemes for different load of Th-232 are considered.The result shows that the main trans-mutation product of Th-232,obsorption is U-233,which has a higher value of η than U-235 andPu-239.On the condition of the same initial excess reactivity,with the deeping of burnap andmore loading of Th-232,more fissile materials are yielded in the core, and hence the conversionratio is raised.Thus,the core lifetime is prolonged and the nuclear fuel are saved, showing thatthorium is a promising energy resource.In addition, when the parameters studied are used,the weight ratio of thorium to uraniumshould optimally be approximatively or less than 0.25([W 2/(W5 + W3)] <0.25).