The Development of Beishan Underground Research Laboratory for Geological Disposal of HLW in China

With the rapid development of nuclear power in China, the disposal of high-level radioactive waste (HLW) has become an important issue for nuclear safety and environmental protection. This paper introduces the overall planning and the latest progress of China's URL (underground research laboratory).The Xinchang site in the Beishan area, located in Gansu Province of northwestern China, has been selected as the final site for China's first URL. In the process of characterizing the Xinchang URL site, a series of investigations, has been conducted. The investigation results indicate that the Xinchang site are very suitable for URL construction. From 2016 to 2020, the main functions and structure of the Beishan URL have been designed, examined and updated. The main functions of the Beishan URL are designed to develop disposal technologies and disposal concept, and estimate the cost of a repository, characterize the site by obtaining key parameters of the deep geological and hydrogeological conditions, carry out engineering-scale tests, verify the safety performance of engineered barriers, provide parameters for repository safety assessment and environmental impact assessment, and establish a platform for the public communication to increase public confidence and support rate. The main structure of the Beishan URL consists of one personnel shaft, two ventilation shafts, one sprial ramp, and two experimental levels. The maximum depth of the URL is -560 m. The ramp is about 7 km in length, with a cross-sectional diameter of 7 m, maximum inclination of 1:10. The use of tunnel boring machine (TBM) is proposed for the ramp excavation as it will less disturb the rock mass and be faster and safer than traditional drill-and-blast excavation. From the shafts, horizontal tunnels are planned to be constructed at two levels for in situ experiments, i.e., the main level at -560 m and the auxiliary level at -240 m.The Beishan URL is currently under construction and it is expected to be completed in 2027. Meanwhile, many tests focusing on site characterization and engineering technology is planned to be performed during construction. Site characterization activities will continue along with ramp excavation. Activities related to construction technology will be conducted along the ramp and at the level of - 560 m. It is anticipated that the technologies and experience obtained from the Beishan URL will contribute greatly to the future success of a HLW geological repository in China and similar facilities around the world. (author)