压水堆高放长寿命裂变产物堆内嬗变平衡循环设计

Equilibrium Cycle Design for LLFPs Transmutation in PWRs

基于压水堆多燃料循环管理计算,进行长寿命裂变产物(LLFP)核素堆内嬗变分析。基于长寿命裂变产物核素在乏燃料中的比重及核素的放射毒性,129I和99 Tc作为当前嬗变研究的主要裂变产物。为避免碘同位素分离,参照乏燃料中127I和129I的组分比例,设计当前的碘化物嬗变靶件。将嬗变核素均匀弥散在惰性慢化材料ZrH2中,放置在控制棒导向管内进行嬗变分析计算。基于该嬗变组件设计方案,对不同的换料方案进行评价和比较,进而搜索嬗变平衡循环。计算显示,当前带有靶件组件的布料方案可达到平衡循环,并能实现LLFP的嬗变。进一步嬗变优化方案设计受限于当前嬗变组件设计。

The performance of the pressurized water reactor（PWR） for the transmutation treatment of long lived fission products（LLFPs） was evaluated.The LLFPs selected in the transmutation analysis include 99Tc and 129I discharged from spent nuclear fuel,based on the inventory and the radiotoxicity evaluation.The isotope 127I was also considered to avoid the separation.By loading the transmutation targets（metallic forms of technetium and magnesium iodide） with the inert matrix material ZrH2 in the control rod tube,the fuel cycles in different shuffle design patterns were simulated and studied.Based on these results,equilibrium fuel cycle might be achieved and sound transmutation performance can be obtained in the PWR.However,the fuel shuffle schemes were limited by present transmutation assembly design pattern.