Another round of looking at potentially less expensive options to treat the stew of radioactive and hazardous chemical waste stored in Hanford’s underground tanks has brought out the skeptic in some Northwest officials.
“Just once I’d like to hear ‘How can we do it better? How can we ensure protection for as long as these wastes remain hazardous?’” said Ken Niles, nuclear safety administrator for the Oregon Department of Energy.
Countless times since cleanup regulations were formulated in 1989, new political administrations and new U.S. Department of Energy officials have asked for a fresh look at options, saying that environmental cleanup at Hanford is taking too long and costing too much, Niles said.
He was among the invited speakers at a two-day meeting in Richland last week of leading national researchers assembled as a committee of the nonprofit National Academies of Sciences, Engineering and Medicine.
Amidst rising cost projections to build and operate the vitrification plant at the Hanford nuclear reservation, Congress asked in the fiscal 2017 budget act for an analysis of options for treating some of Hanford’s 56 million gallons of radioactive waste held in underground tanks. It also directed that the National Academies review the analysis, which is underway by experts picked by the Department of Energy in Washington, D.C.
The Hanford nuclear reservation’s vitrification plant has been under construction since 2002 to treat much of the tank waste left from the past production of plutonium for the nation’s nuclear weapons program.
Plans for its operation are driven by the 10 percent of tank waste considered high level radioactive waste. It includes 95 percent to 97 percent of the waste’s radionuclides, including plutonium.
But the plant was never planned to treat all of the 90 percent of the low activity radioactive waste in a reasonable time.
Grouting versus vitrification
Washington state officials support eventually expanding the vitrification plant, which now is estimated to cost more than $17 billion, to treat all of the low activity radioactive waste.
“We think vitrification is the solution,” said Alex Smith, Nuclear Waste Program manager for the Washington state Department of Ecology, a Hanford regulator. “There is a lot of investment that has already been made by the Department of Energy into vitrification and these facilities.”
Legal documents, including the Tri-Party Agreement and a federal court-enforced consent decree, also require or are based on the plan to vitrify all of Hanford’s tank waste, she said. The vitrification plant would produce glass logs immobilizing the waste.
But a spring 2017 report by the Government Accountability Office said that its expert panel had determined that grouting — mixing the waste into a concrete-like substance — would be less expensive than vitrifying some of the excess low-activity radioactive waste and allow the waste to be treated sooner.
Grouting technology has matured since the U.S. DOE made the decision more than 20 years ago to vitrify Hanford tank waste, the report said.
It estimated that grouting low activity radioactive waste at U.S. DOE’s Savannah River Site in South Carolina would cost $153 per gallon of waste, while the average cost of vitrifying low activity radioactive waste at Hanford would be $1,081 per gallon.
Grouting has previously been studied at Hanford and rejected, Smith said.
In the late 1980s, four test vaults were built at Hanford to hold grouted low-activity radioactive waste. Photos from the project show the vaults towering over pickup trucks at the construction site.
The plan was dropped after the estimated number of vaults needed grew to more than 200, each with a capacity of 1.3 million gallons, increasing the cost of the project. The vaults would cover much of central Hanford, according to some speakers.
Since then the federal government has made commitments to the state of Washington that Hanford’s low activity radioactive waste tank would be vitrified, Smith said.
In the 1990s the federal government did not have the budget to proceed with treating waste at both Hanford and at Savannah River, which also produced plutonium.
DOE told the state that Savannah River’s vitrification plant would be built first, but in exchange for the delay at Hanford, all of the Hanford low activity waste would be vitrified, Smith said.
Multiple studies have shown that grout would not perform as well as glass to keep low level radioactive waste immobilized once the treated waste is buried at a Hanford landfill, local officials said. Radioactive contaminants would leach out of grout into the groundwater and then move toward the Columbia River over thousands of years.
Those studies include a comprehensive look at alternative ways to treat low activity radioactive waste from 2003 to 2006, which found that grout was “not as good as glass,” Smith said.
Groundwater would be contaminated at four times the drinking water standard for radioactive technetium 99, the analysis found. The low activity waste will include both technetium 99 and radioactive iodine 192.
Although the GAO report said that grouting technology had improved, “so far we have not seen documentation that validates that claim,” Niles said.
Northwest residents who rely on the Columbia River will need more than generic statements that “experts agree” that grouting has improved, he said.
And, Niles added, not all experts agree. Even one expert in the GAO report acknowledged that grout is a porous material, which would allow water infiltration, he said.
The quantity of waste that the vitrification plant is not sized to treat has been estimated at a half to a third of the low activity radioactive waste.
How much waste will need treatment
But speakers said that the amount of extra waste is shrinking, a factor in analyzing treatment costs.
Under one proposal being studied by DOE, some of the low activity radioactive waste could be sent to a commercial waste treatment company, Perma-Fix Northwest, for grouting and then sent to a new commercial repository in Texas for federal radioactive waste.
The state is less concerned about grouted waste that will be sent out of state for disposal rather than buried at Hanford, Smith said. But it is concerned that if a problem should develop, the grouted waste could be stranded at Hanford with no plan for disposal.
In addition, a new plan to start treating low activity radioactive waste at the Hanford vitrification plant at least a decade before high level radioactive treatment begins, will allow more of it to be treated before high level radioactive waste treatment is completed, Smith said.
Work also has been done to increase the amount of waste loaded into each glass “log” produced at the vitrification plant for disposal, increasing the efficiency of the plant.
The state still believes that some additional method will be needed to treat some of Hanford’s low activity radioactive waste, but the committee should consider how much as it assesses any analysis of cost, she said.
Pros and cons
Hanford Communities, a coalition of local governments near Hanford, is concerned that new treatment approaches, which may or may not work, will divert money from the current treatment plans, said Pam Larsen, executive director of the organization.
“This is very serious to the people who live in our region,” she said. “A lot of low activity waste is going to be buried in our backyard.”
The Tri-City Development Council, which works to get federal funds to continue environmental cleanup at Hanford, cautioned that cost should be a consideration.
“We cannot let the ‘perfect’ be the enemy of the ‘good and realistically achievable’ ” or the site never will be cleaned up, said David Reeploeg, TRIDEC vice president for federal programs.
TRIDEC supports having all options considered and then closely weighing cost versus performance to move forward in a reasonable time to get cleanup results that the community can live with, he said.
Hanford cleanup spending, which is now at about $2.4 billion a year, already falls short for what needs to be accomplished, he said.
Obtaining money for Hanford will only become more difficult as nuclear weapons sites elsewhere in the nation are cleaned up and Congressional representatives in those states lose interest in financially supporting the nationwide cleanup effort, he said.
The National Academies committee plans additional meetings in July, September and February 2019. It plans to issue four reports as it reviews the analysis of the team assembled by DOE.