HFETR 80MW运行时二次侧水流量衰减瞬态分析

Transient Analysis of Water Flow Decay of Secondary Circuit During the Operation of HFETR 80 MW

燃料元件的壁温是影响包壳完整性的一个重要因素。HFETR功率运行时发生二次侧水流量衰减后,HFETR的固有安全性能否确保燃料元件温度不超运行限值是本文研究的重点。因此,本文基于RELAP5程序建立了HFETR回路系统模型,对HFETR 80 MW运行时不同程度的二次侧水流量衰减情况进行模拟分析,并假设运行人员不人为干预。结果表明:在不进行人为干预的30 min内,仅依靠反应堆保护系统自动停堆,燃料元件的壁温最大值为174.7~174.8℃,小于允许限值(195℃)。即使在二次侧水完全断流且运行人员不进行任何操作的30 min内,反应堆仍处于安全状态,可避免人因误操作而引入的安全风险。

The wall temperature of fuel element is an important factor affecting the integrity of the cladding.After the attenuation of secondary circuit water flow occurs during HFETR power operation,whether the inherent safety of HFETR can ensure that the fuel element temperature does not exceed the operating limit is the focus of this paper.Therefore,this paper established the HFETR loop system model based on RELAP5 program,simulated and analyzed the secondary circuit water flow attenuation of HFETR 80 MW in different degrees,and assumed that the operator did not intervene.The results show that the maximum wall temperature of the fuel element is 174.7~174.8℃,which is less than the allowable limit(195℃),depending on the reactor protection system to shut down automatically within 30 minutes without human intervention.Even after the secondary circuit water is completely cut off and the operator does not conduct any operation within 30 minutes,the reactor is still in a safe state,which can avoid the safety risk introduced by human misoperation.