KENNEWICK — The Department of Energy is moving forward on a demonstration project to stabilize 2,000 gallons of radioactive waste in grout, five years after an initial successful test of three gallons.
A pilot project called the Test Bed Initiative is being used to see if encapsulating Hanford nuclear reservation waste in concrete-like grout could be used for treatment in addition to glassifying radioactive waste at Hanford’s vitrification plant.
Unlike proposed waste grouting projects decades ago, the grouted waste would not remain at Hanford but would be sent out of state.
The results of the test project will be used to evaluate the benefits of further use of grouting for some of the least radioactive waste stored in underground tanks as DOE and its regulators discuss a path forward for tank waste treatment.
The federal government needs to add more waste treatment capacity for the 56 million gallons of radioactive and hazardous chemical waste in underground tanks at Hanford in Eastern Washington. The waste is left from the past production of nearly two-thirds of the plutonium for the nation’s nuclear weapons program.
Construction started on the vitrification plant to glassify some of the tank waste 21 years ago, with the plant still preparing for operations.
But it was not planned to be large enough to treat all of the tank waste, some of it stored in leaking tanks that were built as early as World War II.
Grouting is being considered only for the least radioactive tank waste, which also is the first type of waste planned to be treated at the vitrification plant for disposal at a lined Hanford landfill.
Possible grouting benefits
Grouting could be significantly less expensive, says DOE. One DOE report put the cost savings at $73 billion to $210 billion if a large amount of waste is grouted.
It also could speed up the process to empty leak-prone tanks.
Now, waste in 149 leak-prone single-shell tanks is being transferred into 27 newer double-shell tanks to await treatment, but space in the double-shell tanks is nearing capacity.
Grouting some of the waste could free up capacity in double-shell tanks.
DOE has applied to the Washington state Department of Ecology, a Hanford regulator, for a permit for the second phase of the Test Bed Initiative, following the first phase that treated three gallons of waste at the end of 2017.
“We are supportive of the implementation and completion of Phase 2 and look forward to achieving what we hope will be the demonstration of a valid path to final appropriate disposal of Hanford’s tank waste in an out-of-state facility,” said Ryan Miller, spokesman for Ecology’s Nuclear Waste Program.
The state agency expects to take public comment on the project in the summer.
DOE says that six months after the permit is issued, it should have equipment installed to retrieve and prepare tank waste for grouting.
DOE had reached the same point in the process in 2019, but then withdrew its application for a Washington state permit in late spring of that year just as public comment on the permit was set to start.
DOE said then that it was withdrawing its application for a permit in light of Ecology’s request to negotiate new legal deadlines for Hanford cleanup.
Soon after that the state and DOE officials entered closed-door discussions on Hanford tank waste and its treatment, which are continuing.
DOE also recently issued two decisions allowing the second phase of the Test Bed Initiative to move forward.
It determined in consultation with the Nuclear Regulatory Commission that the 2,000 gallons of waste legally could be treated and disposed of as low-level radioactive waste rather than high level waste.
It also determined there would not be significant environmental impacts from the second phase of the pilot test that would require a more complete environmental study under the National Environmental Policy Act.
Any plan to grout additional waste would require a separate environmental review.
Sending waste out of WA
The 2,000 gallon test would be paid for with $10 million budgeted for the Test Bed Initiative three years ago by Congress. Additional money is available to remove and dispose of contaminated equipment used in the test.
DOE plans to take waste for the grouting test from a double shell tank in the group called the SY-Tank Farm, which is miles away from work being done to prepare waste for the vitrification plant.
Because waste in the tanks is a mix of high level and low activity radioactive waste, DOE must separate out 2,000 gallons that can be classified as low level waste for the grouting demonstration.
It plans to insert a system into the SY-101 double shell tank that will use an ion exchange column to remove cesium and strontium, which are not low level wastes, from liquid waste in the tank and also use filtration to separate large undissolved solids that may be high level waste.
The waste would be shipped offsite to be grouted, likely to Perma-Fix Northwest near Hanford in Richland.
It would then be sent to a commercial site in Utah or Texas for disposal. The three gallons of Hanford waste grouted in the first phase of the Test Bed Initiative were sent to Waste Control Specialists in Texas for disposal in salt formations devoid of water.
Glassified low activity waste will be disposed of at a Hanford landfill, but questions have been raised about whether water would eventually deteriorate grout if it were buried at Hanford.
Grouting 2,000 gallons of tank waste and sending it off Hanford for disposal would address independent recommendations that DOE has received from several agencies to study the potential cost, safety and environmental performance of tank waste treatment and disposal alternatives.
The agencies that have given that advice to DOE include the Government Accountability Office, the National Academy of Sciences, the Federally Funded Research and Development Center and the Energy Communities Alliance, which includes Hanford-area local governments as members.