研究期間:10302~10312;Radioactive wastes are required to be isolated from the environment to prevent possible contamination. The deep geological repository with multiple barriers is currently recognized as a feasible disposal concept. In an underground disposal site, the radioactive wastes are encapsulated in containers surrounded by a buffer material and the excavation backfilled with a mixture of clay and sand. This study aims at the development of a model simulating the coupling effects of thermal-mechanical behavior using finite element method on a 3-dimentional geometric model of the near field of a repository. The following tasks are planned for the proposed project: 1. Review, compare, and evaluate the deep geological disposal strategy adopted by nuclear-advanced countries in the world; 2. Summarize the potential buffer material can be used in Taiwan, along with the physical, thermal,and engineering characteristics of the buffer material; 3. Develop three dimentional geometric model for the analysis of the near field of a deep underground repository using the multi-borehole approach; 4. Develop finite element analysis program capable of incorporating thermal-mechanical coupling effects in the near field of a repository, such that the temperature and stress distributions in the near fiels can be assessed; 5. Prepare a final report for the project.