CFETR水冷包层模块真空室内破口事故安全分析

Accident safety analysis of the in-vessel LOCA for CFETR water cooled blanket module

使用RELAP5对CFETR水冷固态增殖包层的3#包层模块建立模型,并开展了稳态工况和不同破口面积下的真空室内破口事故分析。结果表明,事故发生后真空室压力迅速升高,小破口事故时,向大泄压罐泄压可防止真空室超压;大破口事故时,真空室超压保护系统无法有效地控制压力上升,且增大泄压罐体积以缓解真空室压力的效果不显著。在添加联箱出口止回阀后,可有效防止冷却剂逆向流动进入真空室,使真空室压力维持在安全范围内,不需要启用真空室超压保护系统。

The module #3 of WCCB blanket for CFETR is modeled using RELAP5. Steady-state operation and in-vessel LOCA with different break areas are analyzed. The results indicate that the pressure in the vacuum vessel increases rapidly. In a small-break LOCA, relieving the pressure to the large suppression tank can prevent the vacuum vessel from overpressure after the accident occurs. In a large-break LOCA, the vacuum vessel pressure suppression system(VVPSS) cannot curb the rise in pressure effectively, and the effect is inapparent by increasing the volume of the suppression tanks to reduce the pressure in the vacuum vessel. After the check valves are added on the outlet pipes of manifold, the coolant reverse flow into the vacuum vessel is effectively prevented,so that the pressure in the vacuum vessel is maintained within a safe range without the need to activate the VVPSS.