Yucca Mountain, NV, is being characterized for disposal of U.S. high level
nuclear waste, which consists predominantly of spent fuel from nuclear reac
tors and radioactive waste from reprocessing. In this paper, the program is
presented in the context of global and U.S. nuclear energy systems and of
international plans for high-level waste disposal. The potential impact of
the proposed repository is discussed in the context of the U.S. Department
of Energy's Total System Performance Assessment-Viability Assessment, the p
rimary tool for assessing how the repository might operate.