KENNEWICK — Two methods could be developed to treat some of Hanford’s radioactive tank waste that would cost significantly less than vitrifying it, or turning it into a stable glass form at the Hanford vitrification plant, according to a draft report by a panel of experts.
The state Department of Ecology says it is keeping an open mind on the proposed technologies, but has many questions about the determination that they would be “as good as glass.”
Ecology, a Hanford regulator, gave its opinion on the proposed options Thursday in Kennewick as a committee of the National Academies of Sciences met to discuss supplemental treatment of low-activity radioactive waste at Hanford.
Congress in 2016 ordered the analysis of options for treating some of Hanford’s 56 million gallons of radioactive waste held in underground tanks, which is being done by a panel of experts from Department of Energy national laboratories.
The waste is left at the site from the past production of plutonium for the nation’s nuclear weapons project.
Congress also directed the National Academies to review the analysis, including a draft report released in April.
The $17 billion vitrification plant was planned to treat all of the high-level radioactive waste in Hanford’s underground tanks, but not all of the low-activity radioactive waste, which makes up an estimated 90 percent of the waste.
The April draft report looked at supplemental treatment methods for low-activity radioactive waste.
Vitrifying the waste, which could be done by expanding the nuclear reservation’s vitrification plant, would have the highest cost at $20 billion to $36 billion, it found.
Encasing the waste in a concrete-like grout would have the lowest cost at $2 billion to $8 billion.
The other possibility is steam reforming, which would blend the waste with dry materials at high temperatures to produce ceramic-like particles at a cost of $6 billion to $17 billion.
However, steam reforming is the least technically mature of the three processes, and grouting would create large amounts of treated waste for disposal, the preliminary report said.
Ecology has long said it wanted a final waste form that is protective of the environment. Any radionuclides that could escape over hundreds or thousands of years could contaminate groundwater.
