Eight Savannah River Site saltstone disposal unit completed three years ahead of schedule

May 24, 2023

Jul. 20—The eight saltstone disposal unit at the Savannah River Site is open for business three years ahead of schedule.

The Department of Energy Office of Environmental Management recently authorized the unit to begin operation.

The Office of Environmental Management is the Department of Energy office tasked with cleaning up the nuclear waste created as the country grew its nuclear arsenal during the Cold War.

At SRS, 35 million gallons of nuclear waste is stored in 43 tanks located in F and H areas. Each of the 43 tanks contains two types of waste: salt and sludge. The sludge makes up around 8% of the volume of the tank but nearly have of the radioactivity. The salt makes up around 92% of the volume and just over 50% of the radioactivity.

The sludge is processed through the Defense Waste Processing Facility, vitrified, placed in specialized glass waste containers and stored in one of two glass waste storage buildings to await transport to a future nuclear waste repository. The salt is processed through the Salt Waste Processing Facility. The extracted high-level waste is sent to the Defense Waste Processing Facility and the low-level waste, called decontaminated solution, is sent to the Saltstone Production Facility which acts as a giant concrete plant and mixes the waste with a concrete-like substance for disposal in the saltstone disposal units.

There are plans for 12 saltstone disposal units at the site.

The first and fourth saltstone units were completed in the mid- to late-1980s. The second unit was completed in 2012 and filled in 2014. The third and fifth units were completed in September 2013. Filling of these two units unit began in February 2017.

The sixth unit, the first mega unit, was completed in May 2017 and it began receiving waste in August 2018.

The mega units can hold up to 33 million gallons of saltstone.

The seventh unit, the second mega unit, was completed in July 2021, eight months ahead of schedule.

Completing the eighth unit, the third mega unit, was an Office of Environmental Management priority, Jim Folk, assistant manager for waste disposition for the Department of Energy's Savannah River field office, said.

Savannah River Mission Completion, the site's liquid waste contractor, managed the construction of the eighth unit. Subcontractors Quality Plus Services, US FUSION & Specialty Construction and DN Tanks completed the site preparation, interior and exterior liner systems, and unit construction, respectively.

Dave Olson, SRMC president and CEO, said the construction was a job well done.

"A construction project of such scale involves the skills and expertise of hundreds of hands and minds," Olson said. "I am proud of the SRMC team and everyone's commitment to furthering our mission through this important project."

Construction and testing of the next unit, the ninth, is slated for completion in fall 2024.

SRMC is also in various stages of constructing the other units: 10, 11, and 12.