反射层对铀氢锆反应堆脉冲行为的影响研究  

Reflector Effect on Pulse Behavior of Uranium Zirconium-hydride Reactor

作　　者：孙晓博 安伟健[1] 胡古[1] 解家春[1] 赵守智[1] 

机构地区：[1]中国原子能科学研究院反应堆工程技术研究部,北京102413

出　　处：《原子能科学技术》2017年第11期2021-2027,共7页Atomic Energy Science and Technology

摘　　要：对于反射层价值相对较大的小型铀氢锆反应堆,反射层对脉冲动力学行为产生的影响不应忽略。为描述该影响,基于Cohn两点动力学模型建立了严格区分堆芯中子和反射层中子的两点脉冲模型,结合具体算例与单点脉冲模型和采用瞬发中子有效寿命修正的单点脉冲模型进行比较。3种模型中单点脉冲模型仅适用于反射层极薄的特殊情况,其结果在大多数情况下与另两种模型有显著差异;修正的单点脉冲模型的结果在大多数情况下接近两点脉冲模型,但由于未考虑堆芯中子和反射层中子随时间变化的非同步性,因而在反射层较厚、引入初始反应性较大的情况下与两点脉冲模型存在明显差异;两点脉冲模型严格区分了堆芯中子和反射层中子,在小型铀氢锆堆的脉冲行为分析和引入巨大正反应性的严重事故分析时应使用此模型。For compact uranium zirconium-hydride reactor which reflectors make considerable contribution to the reactivity, the effect of reflectors on pulse kinetics behaviors should not be ignored. In order to characterize this particular effect, a two-point pulse model based on Cohn^s two-point kinetics model was proposed. According to calculations for specific cases, this two-point model was compared with the ordinary one-point pulse model and the one-point pulse model with the correction of effective lifetime of prompt neutrons. Among all three models, the ordinary one-point pulse model should only be used for extreme cases where reflectors are exceedingly thin, otherwise there would be significant differences between this model and others. Results of corrective one-point pulse model are close to those of two-point pulse model for most cases. For specific cases with relatively thick reflectors and large initial reactivity insertions, the result of corrective one-point pulse model differs obviously from that of twopoint pulse model, since the asynchrony of neutrons in cores and reflectors is not considered in eor-rective one-point pulse model. The two-point pulse model is able to distinguish neutrons in cores and reflectors, thus it shall be used in analyses of pulse behaviors of compact uranium zirconium-hydride reactors and severe accidents with significantly large positive reactivity insertions.

关 键 词：铀氢锆反应堆 反射层影响 反应堆动力学 

分 类 号：TL327[核科学技术—核技术及应用]