Destruction of millions of gallons of radioactive and chemical wastes stored for decades in leaking underground tanks at the US Energy Dept.'s Hanford waste site in Washington state now will begin with startup of a new facility in the storage area that is set to remove cesium and solids before the toxics are turned into inert glass, with treated waste disposed of in an onsite landfill, or with some quantity possibly sent to an offsite disposal facility.
Pumping of waste into the site’s $130-million Tank-Side Cesium Removal System, which began late last month, is a key step before an estimated 56 million gallons of waste generated in one-time production of nuclear weapons at Hanford, are immobilized in the site’s multi-billion-dollar vitrification plant, under construction for 20 years and set to come on line by the end of 2023 under state and federal order.
That project team, under the direction of Bechtel National Inc., is expected to begin heating up the plant's first melter within the next few weeks.
"For the first time we can say we have begun pretreating and conditioning tank waste," says John Eschenberg, president and CEO of DOE site contractor Washington River Protection Solutions, headed by Amentum and Atkins. It is responsible for preparing delivery of the waste stored in Hanford tanks to the vitrification plant. "We are on a journey to treat one million gallons by the end of this calendar year," he said,
The system removes the cesium and solids using filtration and an ion exchange system tested at DOE’s Savannah River site in South Carolina and Oak Ridge lab in Tennessee, Eschenberg says. It is designed to treat about five gallons per minute or 7,200 gallons per day.
The system has so far treated more than 90,000 gallons.
Designed as a five-year demonstration project, the system is expected to treat and stage one million gallons of waste by the time the vitrification plant is on line. DOE site manager Brian Vance says its viability will then be assessed for future use.
Over the course of five years, officials estimate they will expend roughly 150 ion exchange columns—at a cost of $1 million per column—and spend up to $200 million in total to operate the facility.
"We see this as a great project to ... learn from and develop a way ahead that we think is affordable and achievable,” Vance says. “We are leaving a lot open, but it creates some opportunities for us in the future."
Using engineering lessons learned from the Savannah River system, WRPS worked with subcontractors AVANTech, Atkins Nuclear Secured LLC, Fowler General Construction Inc. and Apollo Mechanical Contractors Inc. to design and build the pretreatment system. It was fabricated in Columbia, S.C. with final assembly offsite in Richland, Wash., before installation in Hanford’s tank farm area less than one-quarter mile from the vitrification plant. The project was finished ahead of schedule and under budget, WRPS says.
Energy Secretary Jennifer Granholm is set to visit Hanford, for the first time, later this month.
The tahk waste treatment effort comes as a new DOE report projects that completing cleanup of the entire Hanford nuclear complex will cost an estimated $300 billion to $640 billion, a cost range reduction since the analysis was last done in 2019, says the Tri-City Herald. But more than $200 million of the total's low-end estimate will be spent on emptying tank wastes, and treating and disposing them, DOE's report says.