While the Department of Energy is increasingly interested in using grout to solidify some low-level radioactive waste left from decades of plutonium production at its Hanford Site in Washington, operation of such a facility would not begin before the 2030s, according to a recent report.
Various scenarios from DOE and its state regulator, the Washington Department of Ecology, envision using concrete-like grout to solidify much of Hanford’s lower-risk radioactive tank waste as early as 2034 or as late as 2050, according to River Protection System Plan 10, published over the holidays.
DOE and the state publish an update to the System Plan for Hanford every three years and the latest 390-page version was posted online Dec. 27.
In various studies, grout has been identified as a viable backup for portions of Hanford’s low-level waste that cannot be suspended in solid glass by the Bechtel-built Waste Treatment and Immobilization Plant, the current disposal pathway for such waste. DOE has agreed to a Government Accountability Office recommendation to include cost estimates for grout in future system plan updates.
There is an estimated 56 million gallons of liquid waste held in underground tanks at Hanford. The Waste Treatment Plant will, eventually, vitrify all of the high-level waste there into a glass-like solid.
The plant will also solidify 40% or more of the low-level waste, which accounts for most of the volume, but far fewer radionuclides, of Hanford’s liquid tank waste, DOE has said. Direct-Feed-Low-Activity Waste Facility operations are targeted for early 2025.
In research by the Savannah River National Laboratory in South Carolina and the National Academies of Science, grout has been deemed a reliable and more-economical option than building a second vitrification plant at Hanford. State officials have said they are open to considering grout as a backup to glass.
Since the last time this plan was published, the projected baseline life-cycle costs have shot up by a few billion dollars and the timeline for emptying all the underground tanks at Hanford would take about four years longer than envisioned.
Three years ago, DOE’s baseline estimate suggested it would cost between $107 billion and $192 billion to empty all the tanks by 2066 and would cost between. The high-end figure was adjusted for inflation.
The new system plan uses a baseline scenario funded at about $2.7 billion annually “before escalation,” meaning inflation, according to a report footnote. That equates to spending about $123 billion, or roughly $213 billion with inflation, to empty the tanks by 2070. Under this scenario, high-level waste vitrification starts in 2038 with waste being removed from all of Hanford’s single-shell tanks by 2058. The rest of the tank-waste work would conclude by 2070. The $2.7 billion is about equal to Hanford’s appropriations for 2023.
System Plan 10 provides computer modeling analysis on various technical scenarios and provides rough cost and schedule estimates cleaning up the site and protection of the Columbia River. Some of the scenarios show cleanup stretching into the 2080s.
The latest plan also takes into account time lost due to COVID-19 restrictions between March 2020 and March 2022, and resulting deadline extensions granted by a federal court.
“I wanted to reiterate that System Plan 10 is not a decision document, and also doesn’t result in a commitment of funds for a certain approach,” Washington Ecology spokesperson Ryan Miller said in a Thursday email reply to the Exchange Monitor. “System Plan 10 reflects the best-known agency perspectives at this time based on cost, scope, and schedule factors, and is just one element of further discussions and prioritization of activities moving forward.”
