大破口事故下事故容错燃料热工水力行为分析

ATF Thermal Hydraulic Behavior on LBLOCA Condition

事故容错燃料是事故应对能力更强的一种新型燃料,能够在较长时间内抵抗严重事故工况。本文基于TRACE程序考察了常规锆包壳与316SS、SiC、FeCrAl三种事故容错包壳材料在大功率压水堆破口事故下的PCT变化规律,并比较了三种材料对PCT的收益,计算结果表明SiC得到的收益略高为32 K。采用新型事故容错材料仅改变包壳材料即可得到PCT收益,对核电厂的安全性和经济性有重要意义,但随之而来的验收准则和引入的风险也会不同,还需要对此进行深入研究。

ATFs are new fuels/cladding that can tolerate loss of active cooling in the core for a considerably longer time period,in comparison with the standard UO2/Zircaloy（Zr） system.Three types of ATFs,316 SS,SiC,FeCrAl,are analysis on the LBLOCA condition for high power NPP in this paper.And the PCT benefits and the law of PCT distribution using those materials are calculated.According to the result,the material which gets the maximum PCT benefit reached is SiC,32 K.We can see that even ATFs have some advantage on some kinds of accident,the acceptance criteria and risk in using the ATFs should be studied clearly.