Remediating High-Level Radioactive Liquid Waste at the Savannah River Site (SRS)
Savannah River Mission Completion (SRMC), a team that includes Amentum, is responsible for immobilizing radioactive liquid waste and closing the underground, high-level radioactive liquid waste storage tanks at the Savannah River Site (SRS) near Aiken, South Carolina, U.S. Amentum, through its heritage companies, led liquid waste management operations at SRS beginning in April 1989 through the Savannah River Remediation Liquid Waste Disposition Contract, which concluded on February 27, 2022. The SRMC team is providing environmental solutions to eliminate the state of South Carolina’s number 1 environmental risk.
More than 50 years of Cold War production of nuclear weapons materials generated more than 165 gallons of liquid high-level waste (HLW), which has been concentrated to a present volume of approximately 34 million gallons of HLW. The waste is stored in single- and double-shell tanks in the SRS Tank Farms. Originally numbering 51 tanks, eight waste tanks are now operationally closed. The waste remains in 43 tanks, which are in various states of the waste removal, cleaning, and operational closure process.
The cornerstone of SRMC’s activities is the operation of the Defense Waste Processing Facility (DWPF), the nation’s only radioactive waste glassification plant. Since DWPF began operations in 1996, more than 4,300 canisters of vitrified waste have been produced, suitable for long-term storage and ultimate disposal. Amentum has operated waste vitrification facilities (in the US and UK) and is participating in the construction of a DWPF sister facility at the Department of Energy’s Hanford Site.
Other major operations within SRMC include separating the liquid HLW, destined for vitrification, from very low-level radioactive liquid waste that constitutes most of the waste tank volume. SRMC decontaminates that liquid at the Salt Waste Processing Facility (SWPF), then sends it to the Saltstone Production Facility, where the waste is mixed with dry materials to create a cement-like grout, which is pumped into huge concrete disposal units for permanent on-site disposal. More than 26 million gallons of decontaminated salt solution from the tanks have been solidified.
The goal is to treat waste, then empty and grout aging storage tanks and support systems. Amentum, with its heritage companies, is the first company in the world to operationally close HLW tanks.
Amentum is one of the safest high-risk, high-hazard industrial contractors in the world. Amentum’s legacy company at SRS won the first-ever DOE Voluntary Protection Program Star for safety as a major DOE Cold War strategic materials production site and continued to be recertified every year since inception.
Significant Liquid Waste Program Accomplishments:
- Legacy Liquid Waste Contractor awarded DOE VPP Legacy of Stars (2010), Stars of Excellence (2020)
- Legacy Liquid Waste Construction accrued more than 36.4 million safe hours
- 2018 DOE Project Management Excellence Award for Saltstone Disposal Unit (SDU) 6 Project
Significant Salt Waste and Sludge Waste Accomplishments:
- 6 million gallons of salt transferred to SWPF
- 5 million gallons of sludge transferred to DWPF
Significant Waste Disposal and Tank Closure Accomplishments:
- 8 waste tanks permanently closed
- ~4,300 HLW canisters produced at DWPF
- ~1,200 canisters double stacked in Glass Waste Storage Building (GWSB) 1
- ~2,000 canister storage positions modified for double-stacking canisters in GWSB 1 and 2, avoiding the $130 million cost for construction of a new storage building
- 1 million gallons of decontaminated salt solution and other materials transferred to the Saltstone Production Facility
- 6 million gallons of grout (decontaminated salt solution and cementitious materials) permanently disposed of in SDUs