事故工况主控室内渗漏对辐射剂量影响初探

Preliminary Study on the Effect of Main Control Room Inleakage on the Radiation Dose under Accidental Condition

为解明事故工况主控室内渗漏带来的辐射影响,针对某CAP1000沿海核电厂,以关键的失水事故为代表,系统性地研究了放射性的产生、安全壳内去除、环境释放、大气弥散等基本方法。通过数值计算,识别出不同内渗漏风量下主控室内放射性核素浓度变化规律,并进一步量化了人员剂量与内渗漏风量、内循环风量之间的耦合关系。研究结果表明,内渗漏风量每增加10 m^(3)/h,有效剂量增加约2.5 mSv,甲状腺剂量增加约52 mSv,内渗漏试验中应重点关注甲状腺剂量的达标性;内渗漏准则取值25.5 m^(3)/h,从辐射安全角度可接受。因此,本研究建立的方法能够用于支撑核电厂内渗漏准则的确定。

In order to clarify the radiation impact caused by main control room inleakage under accidental condition,based on a CAP1000 coastal passive nuclear power plant,a systematic study on the basic method were carried out for the key loss of coolant accident,including radioactivity generation,nuclide removal in containment,environmental release,atmospheric dispersion.Through numerical calculation,the change law of radionuclide concentration in the main control room under different inleakage was identified,and the coupling relationship between the dose,inleakage and recirculation flow were further quantified.The results show that for every 10 m^(3)/h increase in inleakage,the effective dose increases by about 2.5 mSv,and the thyroid dose increases by about 52 mSv.In the inleakage test,attention should be paid to the compliance of the thyroid dose limit.25.5 m^(3)/h is acceptable for inleakage criterion,from to support the determination of inleakage criteria in nuclear power plants.