Analysis of Environmental Impact of Disposal of Uranium Waste in Surface Landfill Facilities

Front-end nuclear fuel cycle facilities generate a significant amount of uranium waste during operation and decommissioning, characterized by long half-life and high toxicity. Locating disposal facilities near these sites poses challenges due to safety concerns. To address this issue, the Chinese government has approved the construction of a disposal facility in a sparsely populated area of Gansu Province, aiming to centralize the disposal of uranium waste from across the country and minimize disposal risks. This study focuses on assessing the long-term environmental impact post-closure of the landfill facility. By simulating uranium migration under actual hydrological conditions using a storage chamber model, the analysis evaluates whether the public dose constraint requirements can be met. Results indicate that radionuclides begin to enter the biosphere approximately 400,000 years after landfill closure, with the public dose peaking at 2.23 × 10^–2 mSv/a after 2,000,000 years, meeting the dose constraint value of 0.25 mSv/a. Additionally, uncertainty analysis suggests enhancing the anti-seepage efficiency of the HDPE membrane and increasing the thickness of bentonite during landfill facility design and construction to mitigate environmental impact, along with improving water conductivity of overburden drainage sheets.