压水堆严重事故下封头热斑计算  

Calculation on Hot Spot of Bottom Head under Severe Accident of PWR

作　　者：周涛[1,2,3] 王尧新 杨旭[1,2,3] 

机构地区：[1]华北电力大学核科学与工程学院,北京102206 [2]华北电力大学核热工安全和标准化研究所,北京102206 [3]非能动核能安全技术北京市重点实验室,北京102206

出　　处：《原子能科学技术》2017年第7期1214-1218,共5页Atomic Energy Science and Technology

基　　金：北京市自然科学基金资助项目(3092016);中核核反应堆热工水力技术重点实验室基金资助项目(20130901)

摘　　要：压水堆堆芯熔化事故情况下,下封头热斑会造成压力容器局部过热,导致临界热流密度发生。利用FLUENT软件对堆芯熔化事故时的下封头热斑进行计算,从流动和换热角度预测热斑导致的下封头薄弱环节。计算结果表明:堆芯熔化事故时,压力容器下封头存在两处最薄弱的位置,分别为下封头正下方正对外部冷却水位置和氧化壳与压力容器交界处。特别是在氧化壳与压力容器交界处,由于多种原因导致临界热流密度发生,使得该处熔化严重。通过设置延伸小管和附加冷却水可延迟压力容器壁面熔穿的时间。Under core melt accident of pressurized water reactor,the hot spot of bottom head causes local overheating of pressure vessel.This severe accident leads to critical heat flux.The hot spot of bottom head was calculated under core melt accident by using FLUENT software and the weaknesses of bottom head from the view of flow and heat transfer were predicted.The results show that when the reactor core melts,there are two weakest locations in bottom head of pressure vessel,which are bottom of bottom head and border of oxidized shell and pressure vessel.On the border of oxidized shell and pressure vessel,variety reasons cause critical heat flux,so border of oxidized shell and pressure vessel suffers severe accident.The melt time of pressure vessel wall can delay by setting the extension tube and additional cooling water.

关 键 词：堆芯熔化事故 下封头 热斑 

分 类 号：TL333[核科学技术—核技术及应用]