Pursuant to a congressional request, GAO reviewed the Department of Energy's (DOE) plans for radioisotope thermoelectric generator (RTG) assembly operations, focusing on: (1) where DOE plans to assemble RTG in the future; (2) the cost to overhaul the Mound facility to make it suitable for long-term RTG assembly operations; (3) how DOE will address public safety concerns about maintaining nuclear operations in a residential area; and (4) DOE expenditures to modify the Hanford facility in preparation of RTG assembly.

GAO found that: (1) DOE plans to continue RTG assembly and testing at its Mound facility through the completion of the National Aeronautics and Space Administration's (NASA) Cassini mission in October 1997, but it has not developed a plan for reliable, uninterrupted RTG support after the Cassini mission; (2) DOE has cancelled its Hanford RTG project because it plans to keep long-term RTG support at the Mound facility, but the plant may be closed under DOE consolidation plans; (3) DOE believes Mound RTG operations will be less expensive than completing the new Hanford facility, since the Air Force cancelled its RTG requirements; (4) DOE does not want to introduce new RTG operations at the Hanford facility because it is in the cleanup-and-restoration stage of its life cycle; (5) DOE has not estimated the cost of long-term RTG operations at its Mound facility; (6) DOE believes that RTG operations at the Mound facility do not pose a nuclear hazard problem for the residential area, since the nuclear material used will be encapsulated; and (7) DOE has spent $25.7 million on the Hanford facility and estimates it will cost an additional $24.2 million to complete the project by September 1995.