TRISO钍铀包覆燃料颗粒裂变气体生成规律  

Investigation of fission product gas formation in TRISO Th/U coated fuel particles

作　　者：尹文静[1,2] 张海青[1] 曹长青[1] 林俊[1] 朱智勇[1] 

机构地区：[1]中国科学院上海应用物理研究所嘉定园区,上海201800 [2]中国科学院大学,北京100049

出　　处：《核技术》2014年第1期62-67,共6页Nuclear Techniques

基　　金：中国科学院战略性先导科技专项(Grant No.XDA02030200)资助

摘　　要：三结构同向性型(Tri-structural iso-tropic,TRISO)包覆燃料颗粒产生的裂变气体是影响燃料元件安全性的一个重要因素。本工作利用ORIGEN计算程序,研究了基于热堆的TRISO包覆燃料颗粒中裂变气体氙和氪的积累随中子能谱和中子通量的变化规律。计算结果表明,中子能谱、通量和运行时间均相同时,【O2包覆颗粒中氙的生成龄为氪的约7倍,ThO2包覆颗粒中氙的生成量约为氪的4.5倍。研究了ThO2包覆颗粒裂变气体饱和值与能谱的关系,结果表明,能谱越软,越易达到饱和,但能谱较软时达到的饱和值较小。通过对裂变气体积累量的计算估计了ThO2包覆颗粒因内压导致破损的寿命值。Background： Fission product gas accumulation in Tri-structural iso-tropic （TRISO） coated fuel particles can cause the failure of TRISO fuel elements. Purpose： The aim is to study the fission product gases （xenon and krypton） accumulation in UO2 and ThO2 coated particles with respect to various neutron spectra and neutron flux. Methods： Calculations were conducted using ORIGEN code with the neutron databases of THERMAL.LIB, BWRU.LIB, CANDUSEU.LIB and PWRU.LIB as input. Results： It was found that, with the same neutron spectrum, neutron flux and running time, the production of xenon is about 7 times of that of krypton in the UO2 coated particles, and about 4.5 times in the ThO2 coated particles. For the ThO2 coated particles, both xenon and krypton reach saturation earlier when the neutron spectrum are softer, and the saturation values are smaller compared with those in the harder spectrum environment. Conclusion： Taking the fission product gas accumulation as the main factor of TRISO coated particles, the calculation implies that the ThO2 coated particles can have a longer lifetime than the UO2 coated particles under the same neutron environment.

关 键 词：三结构同向性型(Tri structural iso—tropic TRISO)包覆燃料颗粒 裂变气体 中子能谱 中子通量 

分 类 号：TL277[核科学技术—核燃料循环与材料]