高放废物地质处置的安全评价模拟研究：以甘肃北山为例

高放废物安全处置是全球放射性废物管理的重难点问题之一。目前全球拥有核工业的国家正在积极探索安全处置高放废物的前沿课题,但至今尚无高放废物处置库投入运行。我国北山高放废物地质处置地下实验室即将开工建设,因此亟需开展相关安全评价研究,为今后处置库安全评价打下良好基础。本文论述了高放废物地质处置库安全评价的特性,并以处置库首选预选区甘肃北山为对象,开展了高放废物地质处置安全评价模拟研究,旨在为我国高放废物地质处置安全评价提供建议与参考。本文采用蒙特卡罗随机模拟方法,构建了处置库关闭后的破损情景,对拟贮存60 000个废物罐的处置库关闭后100万年期间的辐射水平进行了模拟计算。研究结果表明,甘肃北山处置库100万年内的高放废物有效剂量均低于国际要求的剂量限值,表明该处置库符合高放废物地质处置库的安全要求。本文对于我国甘肃北山高放废物地质处置安全评价的进一步研究具有重要意义。

Safety evaluation study on the geological disposal of high-level radioactive waste-a case study of Beishan, Gansu province

The safe disposal of the high-level radioactive wastes (HLWs) is currently one of the important and difficult problems in the radioactive waste management. At present, all the countries with nuclear industry are actively exploring frontier projects for the safe disposal of HLWs, but there is no HLW disposal repository in the world. As the underground laboratory of the geological disposal of the HLWs in the Beishan, Gansu province is being constructed, it is urgent to carry out the relevant safety evaluation research, laying a good foundation for the safety evaluation of disposal repository in the future. In this paper, we summarized the related characteristics of the safety assessment of geological disposal of the HLWs. Furthermore, we took Beishan pre-selection area of Gansu province as an example to conduct the safety assessment simulation study. In this simulation study, we adopted the Monte Carlo random simulation method to model the damage situation, and to estimate the radiation levels during the period of 1 million years after the closure of disposal repository with the storage of 60000 waste tanks. Our results show that the effective dose of the Beishan disposal repository within one million years is lower than the international dose limit required, suggesting that this repository meets the safety requirements. This study is of important significance to furthe research on the safety evaluation of HLWs in Beishan, Gansu, China.