Summary: The end of the cold war and expected reductions in the nation's nuclear weapons arsenal has prompted the Department of Energy (DOE) to study ways to consolidate the agency's nuclear weapons complex. The agency's first choice is to centralize most of its nonnuclear operations, which produce nonnuclear components for weapons, in Kansas City, Missouri. A number of other nonnuclear activities would move to other DOE facilities or be privatized. GAO is concerned because the costs associated with this plan are uncertain and the technical risks of consolidation have not been thoroughly explored. DOE recognizes some of these weaknesses and is looking into other options, such as moving specific operations to the national laboratories. It is also doing more detailed cost estimates on other options. Some weaknesses, however, continue to receive little attention. Further analysis of additional policy options and technical risks is needed to assure Congress and the public that all reasonable options have been explored and that DOE's approach will minimize risks. Moreover, a specific size for the complex has yet to be decided. GAO believes that the selection of the complex's size and capabilities sets a critical baseline for consolidation planning. Once parameters are placed on the future production capability of the complex, consolidation planning to establish that capability can go forward.