核电站蒸汽发生器排污水监测道报警阈值研究

Alarm Threshold Value of SG Sewerage Radiation Monitoring Channel in Nuclear Power Plant

分析了压水堆核电站在蒸汽发生器一、二次侧发生泄漏的情况下,一回路冷却剂泄漏到蒸汽发生器二回路水的放射性核素,并根据实际情况,考虑了衰变、蒸汽携带和排污净化等因素对二回路水活度浓度的影响,建立了蒸汽发生器一、二回路泄漏的数理模型。假设了3种不同工况下蒸汽发生器一、二回路的泄漏率值,根据数理模型计算出不同泄漏率工况下二回路水的活度浓度,以此作为排污水监测通道阈值设置的依据,提出了针对排污水监测通道的报警阈值设置建议,其中,一级报警阈值的设置与现役电站一级报警阈值相当,二级报警阈值较现役电站二级报警阈值保守。

This article analyzed the radioactive nuclides leaked from the primary loop system to the secondary loop system of pressurized water reactor nuclear power plant under the conditions of the leakage between the first loop and secondary loop of the steam generator. And according to the actual conditions, considering that the influences of the decay, steam - borne radioactive nuclides and sewage clarification to the concentration of the secondary loop water, mathematical models of the leakage of SG first loop and secondary loop under three different operating conditions were assumed. According to the mathematical model, the concentration of the secondary loop water under the different leakage rate was calculated as the basis of threshold set - up of the monitoring channel. Finally, the suggestions for setting the alarm threshold value of the monitoring channel were brought forward. The choice of the low threshold value was close to the operating threshold value of the plant, and the high threshold value was lower than the operating threshold value of the plant.