CEFR一回路管廊通风系统改造后雾状钠火事故分析

Analysis of the Sodium Fire Accident after Upgrade of the Ventilation System of the Primary Loop’s Corridor

中国实验快堆(CEFR)是液态金属钠冷却的快中子实验堆,一回路钠净化系统管廊即309/1房间作为放射性钠气溶胶包容小室之一,房间内布满高温涉钠管道,特别是布置了反应堆主容器内高温强放射性钠流向外部的唯一管道。假使管道破裂,SSW喷射出的高温钠会燃烧引起钠火,在一定条件下,可能会产生持续的雾状钠火,对于房间压力、房间内气体温度、内部结构温度等因素影响很大。基于给309/1房间降温的目的对该房间进行了通风系统改造,改造后的通风系统增大了在309/1房间的正常排风量和正常进风量,这应该会对309房间的钠火事故热力学后果有所影响。本文利用FEUMIX程序计算一回路管廊通风系统改造后发生的雾状钠火事故后果,并与原通风设计条件下的雾状钠火事故后果进行对比,结果表明,通风系统改造对一回路管廊的雾状钠火事故具有一定缓解效果。

CEFR is a fast neutron experimental reactor with the coolant of liquid metal sodium.The primary loop’s corridor of sodium purification system,as we know the name of room 309/1,is one of the sodium aerosol containment chambers,where laid out with many sodium pipes of high temperature In particular,the only pipeline for the flow of high-temperature and strong radioactive sodium in the reactor main vessel to the outside is arranged..In the event that this pipe is broken,the spray of hot sodium can burn and then produce sodium fire,under certain conditions,a kind of continuous spray sodium fire,which affects the pressure and gas temperature of room and the temperature of internal structure,etc.a lot.In order to lower the temperature of room 309/1,the ventilation system of this room is upgraded by means of increasing the air intake volume and exhaust air volume,and this kind of upgrade should affect thermodynamic results of sodium fire accident.FEUMIX is used to calculate the results of spray sodium fire accident of the primary loop’s corridor after upgrade of the ventilation system,and the results is compared with the results of the same room before the upgrade of the ventilation system.It appears that the upgrade of the ventilation system of the primary loop’s corridor can relieve the consequences of the spray sodium fire partly.