积分法评估^(60)Co工业辐照装置卡源事故剂量

Dose Assessment of Source Locked Accident in Cobalt- 60 Industry Radiation Facility Based on Integral Method

利用MCNP程序构建简单人体、辐照室、源井、板源模型,对进入辐照室过程中不同位置处工人的吸收剂量率进行了计算,按指数衰减律拟合出吸收剂量率随空间变化的曲线和函数,采用积分法对进入、滞留、撤离辐照室工人的受照剂量进行了计算。结果表明:工人进入、滞留、撤离辐照室总共花费时间为12.7 s,整个过程受照当量剂量为20.61 mSv,与中国辐射防护研究设计院对事故工人个人剂量计检测结果相吻合。该方法可有效地对随空间变化辐射场中的受照工人个人剂量开展评估。

The model of simple mannequin,radiation room,source well,board radioactive source is constructed by MCNP code. Absorbed dose rates of workers who enter into the radiation room in different position are calculated. According to the exponential decay law,curve and functions of absorbed dose rate varying with space are fitted out. Absorb dose rate of work who enter,stranded,evacuating from irradiation chamber is calculated by integral method. Results show that it costs worker 12. 7 seconds to enter,stay,and leave the irradiation room,and equivalent dose of worker is 20. 61 mSv,which is in agreement with the personal dose monitoring results provided by China Institute for Radiation Protection（ CIRP）. The calculation method can be effectively applied to evaluate the individual doses of the exposed workers in the radiation field which varies with space.