Hanford Cleanup: DOE Should Validate Its Analysis of High-Level Waste Treatment Alternatives, says GAO

The Hanford Site in Washington State is home to one of the largest and most expensive environmental cleanup efforts in the world. After decades of research and production of weapons-grade nuclear materials at the 586-square-mile site ceased in the late 1980s, the Department of Energy (DOE) began cleanup efforts. These efforts include addressing approximately 54 million gallons of hazardous and radioactive waste stored in 177 large underground waste storage tanks. As part of the cleanup mission, DOE must retrieve and treat the waste before disposal, according to legal requirements and agreements made with federal and state environmental regulators.

DOE plans to separate out and vitrify the most radioactive portion of this high-activity waste – which DOE calls high-level waste, or HLW – which represents about 72 percent of the estimated radioactivity in the tanks, though much of radioactivity will decay over the next 100 years.

DOE's current plan for treating this HLW relies on a vitrification facility that will be part of Hanford’s Waste Treatment and Immobilization Plant. This plant is partially complete and faces ongoing technical challenges. In 2023, DOE released an analysis of alternatives that considered 24 options for treating Hanford’s HLW. The analysis found that the life-cycle cost estimates for treating the HLW ranged from $135 billion to $5 trillion. The analysis also found that the current plan, as well as several other alternatives, would require a significant increase in annual funding (up to $8 billion a year) over the next 10 years. According to the analysis, none of the alternatives could complete HLW treatment by 2047—the treatment deadline set in legal agreements with environmental regulators—with the earliest estimated completion date for any alternative being 2061.

DOE plans to select an alternative for HLW treatment in the near future—though no timeline has been set—and has restarted some efforts to complete construction of the HLW treatment facility. According to DOE guidance and GAO best practices, before selecting an alternative, an independent entity should review and validate the analysis of alternatives process. However, DOE has not committed to obtaining an independent review to validate the portions of the analysis of alternatives process related to HLW treatment. Given the enormous cost and schedule implications of the decision, it is essential for DOE to take steps now to provide assurance that all viable alternatives for optimizing the tank waste treatment mission are considered.

What GAO Recommends

DOE should obtain an independent review to validate the process of the analysis of high-level waste treatment alternatives at Hanford. DOE concurred with GAO's recommendation.