内漏测量技术中浓度衰减法应用模拟研究

An Application Simulation Study of the Concentration Decay Method on In-leakage Test technology

核电厂主控室作为核电厂运行的关键位置,在正常和应急情况下保证工作人员在主控室可居留性尤为重要。对核电厂主控室进行可居留性内漏评价能够判断主控室环境是否处于正常安全运行状态,并根据评价结果发现主控室存在的问题进而提出解决方案,是保障主控室正常安全运行的一种评价技术手段。主控室可居留性内漏评价采用示踪气体试验方法,通过浓度衰减法在简单区域进行内漏测量技术模拟研究,结果表明:示踪气体浓度在40 min内能够达到混合均匀,各采样点示踪气体浓度相对标准偏差为3.71%,示踪气体浓度随着时间推移混合均匀性不断提高,房间空气交换次数为0.3/h,内漏量为45 m^(3)/h,空气交换次数的不确定度为0.3/h。采用浓度衰减法进行内漏测量模拟研究,通过对示踪气体注入、采样点布置,气体搅拌装置分布及示踪气体取样分析等过程进行控制,能够实现示踪气体在简单区域内快速混合均匀达到平衡状态。

The habitability of main control room of nuclear power plants is very important for operators both at normal and accident situations,and the test evaluation of air in-leakage into main control room of nuclear power plants can understand whether it is safe to operators at normal and design basic accident condition.The concentration decay method with tracer gas is used to carry out this application simulation study in a single area.Test results show that the mixing uniformity of the tracer gas concentration in the test space can be achieved within 40 minutes,and the relative standard deviation of tracer gas concentrations for all samples is 3.71%,calculated air in-leakage rate is 45 m3/h and its air exchange rate is 0.3 h-1 with an uncertainty of 0.3 h-1.This simulation study proved that the mixing uniformity standard can be met quickly through the controlling of the processes of tracer gas injection,assignment of sampling points,distribution of mixing fans,and analysis of tracer gas concentration in a single area.