AIKEN, S.C. – EM’s liquid waste contractor at the Savannah River Site (SRS) immobilized more decontaminated salt solution (DSS) in the fiscal year that ended Sept. 30 than in the previous five years combined.

Savannah River Remediation (SRR) converts DSS into a grout and safely dispositions the engineered waste form inside mega-volume storage units.

From Oct. 1, 2020 through Sept. 30, the SRS Saltstone Production Facility (SPF) received more than 3.1 million gallons of DSS. In the prior five years of operation, the facility received approximately 2.8 million gallons. SPF mixed the record amount of DSS with cement and dry slag, a byproduct of steel mill production, and fly ash, a byproduct of burned coal. The combination produced just over 5 million gallons of grout for disposal — more than any year in the site's history. The previous five years resulted in the creation of slightly less than 4.9 million gallons.

The accomplishment is the result of increased capabilities across the entire SRS liquid waste program.

The Salt Waste Processing Facility (SWPF), built and operated by contractor Parsons Corporation, is processing greater quantities of high-level waste, resulting in larger amounts of DSS to be converted into grout. SRR is providing the qualified waste feed to SWPF and receiving the DSS for conversion and final disposition.

Once the grout is created at SPF, the mixture is sent to nearby Saltstone Disposal Units (SDUs), which are large concrete units used for permanent disposal of the grout made from DSS. The mega-SDUs each hold approximately 33 million gallons of the grout, which cures into saltstone.

Jim Folk, DOE-Savannah River assistant manager for waste disposition, said the ability to treat and immobilize greater quantities of DSS will help meet the expectations of the SRS liquid waste mission.

“We have strengthened the systems at the Saltstone Production Facility over the course of several years, preparing for increased throughput from the Salt Waste Processing Facility,” Folk said.

Some facility improvements that led to the fiscal 2021 accomplishment and increased overall efficiency include a new grout formula, optimized equipment, and additional trained staff needed for added shifts.

SRR Chief Operating Officer and Deputy Project Manager Mark Schmitz said the upgrades at SPF have enabled the facility to significantly boost its production.

“The overall liquid waste infrastructure is now greatly enhanced,” said Schmitz. “It is exciting to witness the accomplishments of recent investments at these facilities. Achieving these new heights is the result of the innovative approach that has been the hallmark of Savannah River Remediation’s teamwork and continuous improvement efforts.”