It is time for the Department of Energy to arrange an outside review of its potential alternatives for treating the most highly-radioactive waste at the Hanford Site in Washington state, the Government Accountability Office said in a report issued Thursday.
“DOE has not committed to obtaining an independent review to validate the portions of the analysis of alternatives process related to HLW [high-level waste] treatment,” GAO said. “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.”
For its part, the DOE Office of Environmental Management agrees with the recommendation, according to the 43-page GAO report called for in the National Defense Authorization Act of fiscal 2022.
As of January 2023, Hanford’s roughly 55 million gallons of liquid tank waste contains about 118 million curies of radioactivity, GAO said in its report. High-level waste accounts for about 72% of the radioactivity, despite representing only 5% of the volume.
In January, DOE released an Analysis of Alternatives that considered 24 options for treating high-level waste; life-cycle cost estimates for treating the high-level waste ranged from $135 billion to $5 trillion, GAO said. The earliest all the high-level waste will be treated is 2061, or 14 years beyond the 2047 deadline currently set under the Tri-Parties Agreement.
The 2061 date assumes that Hanford’s supplemental low-level tank waste will be grouted.
Alternative treatments such as grout for low-activity waste, “have been widely studied and reviewed by independent organizations,” including the Savannah River National Laboratory and the National Academies of Sciences, Engineering, and Medicine,” GAO said. “However, the HLW treatment alternatives analyzed in the [analysis] have not been similarly studied or independently reviewed,” according to GAO.
Another issue GAO raised is the viability of the tank-side cesium removal pretreatment DOE is using to prepare a portion of Hanford’s low-level waste for solidification. “DOE has not determined whether this technology would be sufficient to pretreat all 54 million gallons of Hanford’s tank waste,” GAO wrote in a footnote in the report.
Other factors will affect DOE’s analysis of alternatives, such as Hanford’s aging site infrastructure and the recently completed closed-door talks before DOE and the other two agencies in the 1989 Tri-Party Agreement, the Washington state Department of Ecology and the U.S. Environmental Protection Agency.
The three parties recently announced an agreement in principle and said they would soon be setting out recommendations arising from the negotiations.
