M310核电站含氢废气处理系统容量分析及优化

核岛含氢废气来自一回路,含有氢气和裂变产生的放射性核素,放射性核素主要是惰性气体包括⁸⁵Kr、^85mKr、⁸⁸Kr、¹³³Xe、¹³⁵Xe,还有少量¹³¹I、¹³²I、¹³³I、¹³⁵I、¹³²Te等。M310核电站广泛使用压缩贮存衰变工艺处理含氢废气,出现了衰变箱容量紧张的问题,制约了一回路吹扫操作,影响大修进程,也形成了安全隐患,亟需改造优化。本文以含氢废气中氢气产生的源头为重点,调查研究各种运行工况及操纵规程、规范,分析气体产生量和组份,判断出关键因素为停堆时容控箱气相空间吹扫过程,通过计算得到气体流量的峰值、总体积和氢气的含量。经过比较分析,在满足放射性衰变前提下,提出了针对各类工艺方案需要配备的合理的系统容量,且具有较好的经济性,避免过大冗余造成浪费,解决了工艺优化的难题。

Capacity analysis and optimization of the hydrogenen containing gaseous waste treatment process for M310 NPP

Hydrogen containing gaseous waste from primary loop consists of hydrogen and radionuclides. Radionuclides include ⁸⁵Kr, ^85mKr, ⁸⁸Kr, ¹³³Xe, and ¹³⁵Xe, as well as small amount of ¹³¹I, ¹³²I, ¹³³I, ¹³⁵I, ¹³²Te etc. Due to shortage of decay box capacity, the purge operation of the reactor coolant system and the overhaul process are affected and hydrogen leakage risk is also created. Pressurized storage decay treatment process which has been widely used to treat hydrogenous gaseous radioactive waste in M310 NPPs needs to be modified and optimized. In this paper, based on hydrogen sources, through the investigation of various normal operating conditions, operating specifications and standards, the gas emission quantity and components ratio were analyzed. We concluded that the key factors are the purge operation of volume control tank and the reactor coolant system. Peak gas flow and total volume, and the volume ratio of hydrogen are shown through the Calculation. Reasonable capacities of different processes are proposed at last, avoiding economic waste caused by excessive redundancy.