The Department of Energy’s latest cost estimate for the Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Richland, Wash., is $18.5 billion – excluding the cost of building and commissioning the High-Level Waste Facilities.
The High-Level Waste Facilities at the mammoth plant, to vitrify tank waste into glass, could run another $14 billion, the Government Accountability Office (GAO) said in a report made public this week.
The $18.5-billion price tag represents a $1.7 billion increase since the last time GAO did a deep dive into project costs in 2022, according to the report released this week.
“The total estimated cost and completion date will increase based on the scope of work that needs to be added to provide the capability to treat Hanford’s high-level waste,” GAO said in a detailed footnote.
DOE’s Office of Environmental Management has said it does not plan to start construction on the High-Level Waste Facility at WTP until the design is 90% complete, hopefully next year. Actual solidification of high-level radioactive tank waste could start in 2033, under current timelines.
The $18.5-billion cost estimate does reflect the costs for the Low-Activity Waste portion of the project and the design phase of the High-Level Waste Vitrification facility, according to the report. DOE has been tracking Hanford cost issues for years.
In October 2025, Hanford crews finally started converting some of Hanford’s less radioactive tank waste into a solid glass form.
Hanford has roughly 56 million gallons of liquid radioactive and hazardous waste held in underground tanks, some of them old single-shell tanks that have already leaked. The tank waste is left over from decades of producing plutonium for the government.
Bechtel National has the WTP construction contract which started in 2000 and is valued at more than $18 billion.
DOE’s Hanford Field Office is also planning to grout a portion of the low-level tank waste at Hanford and dispose of it at sites run by EnergySolutions in Utah and Waste Control Specialists in West Texas.