大型压水堆装载50% MOX燃料方案初步研究

Preliminary Study on Core Design with 50% MOX Fuel in PWRs

在保持堆内构件设计、燃料组件机械设计以及控制棒设计和布置不变的前提下,对大型压水堆应用MOX燃料进行初步研究。在遵守与UO_2堆芯相同的核设计准则的基础上,开展装载50%MOX燃料的堆芯燃料管理方案研究及核特性分析。分析结果表明,堆芯主要物理参数满足设计准则要求,能够实现堆芯运行和控制相关要求,具备装载50%MOX燃料的能力。混合堆芯的有效缓发中子份额比UO_2堆芯有所减小,其对弹棒事故的影响应予以重点关注。

Core design optimization for MOX fuel is an important aspect for new- generation light water reactor. The purpose of this paper is to demonstrate that the 193- assembly two-loop pressurized water reactor studied is capable for MOX utilization without significant changes to the design of the plant including core internal design, fuel assembly mechanical design, control rod design and pattern. A mixed 50% MOX/UO2 core are designed and investigated by comparing with a 100% UO2 core. The MOX fuel utilization has impacts on the nuclear characteristic parameters, but the nuclear and safety criteria same as that considered in the UO2 core design are all satisfied and the operating flexibility is not sacrificed. Because the effective delayed neutron fraction （βeff） of MOX-beard core is lower than that of the 100% UO2 core, much attention should be paid to the impact on the related analysis especially to the control rod ejection accident.