In a draft report presented this week to a National Academies panel, a Department of Energy research team said grout represents the safest bet for treating half of the low-level radioactive waste at the Hanford Site in Washington state.
“Only alternatives employing grout technology appear to be technically viable, low-to-moderate risk, and flexible enough to implement under a range of constrained budget scenarios” without significant impact to Hanford’s Waste Treatment and Immobilization Plant, according to the draft report from the Savannah River National Laboratory in South Carolina.
The authors defended their 200-page January draft report to the Nuclear and Radiation Studies Board of the National Academies of Sciences, Engineering and Medicine during hybrid meetings Tuesday and Wednesday.
The Direct Feed Low Activity Waste Facilities at the plant, which could start operating between 2023 and 2025, only have capacity to turn about 50% of the low-level waste at Hanford into glass, according to the report. Grouting is deemed the best bet for this leftover supplemental low-level waste.
Low-level waste makes up most of the 56 million gallons of liquid tank waste remaining from decades of plutonium production. Vitrification of high-level waste at the vitrification plant, being built by Bechtel, would start by 2033 under a 2022 legal order.
Without supplemental treatment of the less radioactive waste, the tank waste mission could “potentially extend well beyond 2090,” according to the report. Not using a supplemental waste option could mean replacing the Waste Treatment Plant “at least once.”
Grouting supplemental waste and disposing of it off site could start as soon as 2027 and allow DOE to finish tank waste treatment closer to 2070. Grouting would also be cheaper than either building another vit plant or a fluidized bed steam reforming plant similar to the Integrated Waste Treatment Unit being commissioned in Idaho.
The report envisions grouted waste going to either the EnergySolutions disposal site in Clive, Utah or the Waste Control Specialists facility in Andrews, Texas. Grouting could be done at the Perma-Fix Northwest plant in Richland, Wash., eventually done on-site at Hanford, or after arrival at the disposal facilities.
The report indicates lifecycle costs for more than a half-dozen grout options could run from less than $2 billion-to-$4-billion in 2023 dollars; $5-billion to $6-billion for fluidized bed options and nearly $13 billion for another vitrification plant. The new glass-making plant might not be finished until 2050, according to the document.
The 2021 National Defense Authorization Act called for the waste report by a federally funded research and development center, the Savannah River lab in this case, which would be vetted by the National Academies panel. In addition to Savannah River, the report authors also included members from the Sandia National Laboratories and Los Alamos National Laboratory in New Mexico, Pacific Northwest National Laboratory and Parsons Corp.
