Pursuant to a congressional request, GAO discussed the: (1) challenges and uncertainties facing the Department of Energy (DOE) in cleaning up its Paducah, Kentucky, uranium enrichment site; and (2) effectiveness of DOE's oversight and management of its in-tank precipitation (ITP) project.

GAO noted that: (1) DOE expects to complete the cleanup of the Paducah site by 2010 at a cost of about $1.3 billion; (2) however, numerous technical, funding, and regulatory uncertainties present challenges to DOE's ability to complete the cleanup within this timeframe and cost estimate; (3) technical uncertainties include the planned use of technologies that are unproven or perhaps not well suited to the site's conditions; (4) even when the planned cleanup has been carried out, billions of dollars and many years will be needed to address areas at the Paducah site that are not in the cleanup plan; (5) for example, the plan does not include cleaning up nearly 1 million cubic feet of waste and scrap in areas known as DOE Material Storage Areas and 16 unused and inactive buildings and structures; (6) some of the waste and scrap material pose a risk of an uncontrolled nuclear reaction that could threaten worker safety; (7) by not including these areas in the plan, the Paducah cleanup managers cannot assess risk or plan cleanup on a comprehensive, sitewide basis; (8) therefore, the picture of the cleanup task at hand is distorted; (9) a number of management and oversight problems caused DOE and Westinghouse Savannah River Corporation, DOE's contractor, to spend almost a half billion dollars and to take about a decade before deciding that the ITP process would not work safely and efficiently as designed; (10) for example, in 1993, a technical review team reported that the contractor tended to react to problems after they occurred, rather than working to prevent them in the first place; (11) the team also found that DOE lacked the necessary personnel for adequate oversight; (12) DOE and the contractor encountered delays in starting up the ITP facility because they had begun construction before the design of the process was completed; (13) DOE and the contractor encountered delays in starting up the ITP facility because they had begun construction before the design of the process was completed; (14) DOE and the contractor also did not adequately understand the cause of the technical problems--such as a lack of understanding of the chemistry involved in the ITP process--that made the process unworkable; (15) problems that led to the ITP failure may have continued in DOE's efforts to find an alternative; and (16) an October 1999 National Research Council report states that contractors appear to be focusing on an engineering solution on the basis of untested assumptions.