重水堆核电厂氚职业内照射的辐射防护管理实践

Practice of radiation protection management on tritium internal exposure in heavy water reactor nuclear power plant

氚是核电厂常见的放射性核素。由于反应堆堆芯的设计特点, 重水堆核电厂存在较高的氚职业内照射风险。秦山第三核电厂是我国唯一的重水堆核电厂, 拥有2台CANDU6型重水堆核电机组。自2003年全面投入运行以来, 秦山第三核电厂严格开展氚的场所和人员辐射监测, 持续优化氚的监测技术与防护方法, 确保核电厂人员的辐射安全和职业健康。2003-2022年以来, 秦山第三核电厂未发生氚内照射所致的个人超剂量限值受照, 职业照射年人均氚内照射有效剂量低于200 μSv, 平均年度氚内照射集体剂量占电厂总集体剂量年均份额的18.6%, 远低于全世界重水堆核电厂20%~30%的平均份额。由此说明, 氚内照射的剂量监测和辐射防护管理实践是有效的。

Tritium is one of the common radioisotopes in the nuclear power plant.In heavy water reactors,tritium causes the higher internal exposure because of the reactor design.Third Qinshan Nuclear Power Plant(TQNPP)is the only heavy-water-reactor nuclear power plant in China,which has 2 CANDU6 reactors.Since TQNPP were put into commercial operation in 2003,TQNPP strictly performs area and individual tritium radiation monitoring,continuously improves monitoring techniques and personnel protection methods for tritium internal exposure,ensuring the occupational safety and healthy of plant staffs.From 2003-2022,none of incident caused by tritium internal exposure which the effective dose is above the regulatory limits was occurred,the average individual annual tritium internal effective dose is lower than 200μSv,and the percentage of the average annual tritium internal exposure collective dose is 18.6%,which is lower than the average level of 20%-30%around the global heavy water reactor plants,showing that the management practice of tritium internal exposure monitoring and protection in TQNPP is effective.