AIKEN, S.C. – Energy Secretary Rick Perry joined Savannah River Site (SRS) officials Feb. 1 to break ground on EM’s second 32.8-million-gallon liquid waste disposal unit during his first visit to the site.
“We are pleased that Secretary Perry could be here to commemorate this occasion with us today,” DOE-Savannah River Manager Jack Craig said. “The Saltstone Disposal Units (SDU) are an important part of our cleanup mission and underscore the Department of Energy's continued commitment to furthering progress on the closure of the high-level waste tanks at SRS.”
SDUs are permanent disposal units for low-activity waste grout produced from the solidification of decontaminated non-hazardous salt waste at SRS. The groundbreaking was for SDU 7, the second of seven mega units planned to store the remaining tank waste. EM approved the concept of replicating the mega-volume design for all remaining SDUs at SRS.
Tom Foster, president and project manager of Savannah River Remediation (SRR), the SRS liquid waste contractor, noted that SDU 7 site preparation began just three months after SRR completed construction on SDU 6. Workers completed SDU 6 $25 million under budget and 16 months ahead of schedule last year. EM recognized the successful project by naming it the 2017 EM Project of the Year.
“The template created by the liquid waste team from safely completing Saltstone Disposal Unit 6 will continue as we begin construction on Saltstone Disposal Unit 7,” Foster said.
Workers removed structures as part of the SDU 7 site preparation that began in October 2017. They are rerouting above- and below-ground utilities within the SDU 7 footprint to allow for excavation of more than 170,000 cubic yards of soil for the structural base slab.
The mega-volume SDUs will accommodate the larger stream of decontaminated salt solution from the Salt Waste Processing Facility (SWPF), which is scheduled to begin operating in December.
The seven larger units will result in more than $500 million in cost savings over the life of the low-level saltstone waste storage program because less infrastructure and materials are required to design and build the larger SDUs. SRS will need only seven of the larger units to meet mission needs — equivalent to 80 small SDUs, each holding roughly 3 million gallons.
SWPF is key to the SRS liquid waste program and will process the majority of the site’s salt waste inventory. Removing salt waste, which fills over 90 percent of tank space in the SRS tank farms, is a major step toward emptying and closing the site’s remaining 43 high-level waste tanks.