Fifth Mega Saltstone Disposal Unit Approved for Operation at U.S. Savannah River Site

The U.S. Department of Energy Office of Environmental Management announced on August 25 that it has approved the operation of the fifth mega saltstone disposal unit at the Savannah River Site in Aiken, South Carolina. Designated as SDU 10, the facility will receive purified material for final disposal, marking a new milestone in the site's cleanup program.

According to reports, SDU 10 completed construction in June 2024, nearly 10 months ahead of schedule. Its leak-tightness testing was completed in December 2025, and the test results verified that the unit can safely store up to 33 million gallons of purified, solidified salt solution generated at the Savannah River Site.

Saltstone disposal units are the end-stage facilities in the salt waste treatment process. The Salt Waste Processing Facility first produces purified salt solution and sends it to the Saltstone Production Facility, where the salt solution is mixed with dry materials to form a cement-like grout. The grout is then pumped into saltstone disposal units, where it solidifies into a monolithic, non-hazardous solid.

Chuck Comer, the U.S. Department of Energy's Savannah River federal project director, stated that all mega saltstone disposal units at the Savannah River Site have been completed ahead of schedule and within budget while maintaining safety and effectiveness. These facilities provide safe, permanent storage space for purified legacy waste and also help accelerate the site's liquid waste treatment program.

Savannah River Mission Completion, the liquid waste contractor at the Savannah River Site, is responsible for the construction and operation of the relevant disposal units. Thomas Burns Jr., the company's president and project manager, stated that the completion of SDU 10 demonstrates the project team's capabilities in safety, collaboration, and professional execution.

Currently, the company is also advancing the construction of the final two mega saltstone disposal units at the Savannah River Site. This spring, after SDU 11 completed the installation of its final roof section, all structural concrete placement work has concluded, and the unit is now being wrapped with more than 340 miles of steel cable to enhance structural integrity and durability. SDU 12 began construction in April of this year and is the final disposal unit needed to support the site's radioactive waste tank cleanup mission.