DOE Designs New Mixer But Not For The Kitchen

Aiken, SC, -- Buying a new mixer is a simple shopping task for most, unless you’re the Department of Energy’s (DOE) Savannah River Site (SRS). A new mixer at SRS isn’t for the kitchen. Its job is on a grander scale -- to mix highly-radioactive salt waste stored in underground tanks here for disposal.

A joint project team composed of both Savannah River Remediation LLC (SRR) and Savannah River National Laboratory (SRNL) research scientists and engineers is currently confirming performance specifications for four first-of-a-kind mixer pumps to accelerate the processing of radioactive salt waste at SRS. The $5.2 million initiative, funded under the American Recovery and Reinvestment Act, supports a major Salt Disposition Integration project being undertaken by SRR.

“Development and operation of the unique pumps will support the preparation of the salt feed to the $1.3 billion Salt Waste Processing Facility (SWPF) currently under construction by Parsons Infrastructure and Technology Company at the SRS site and currently scheduled to become operational in 2013,” said Jean Ridley, the DOE Liquid Waste Recovery Act Federal Project Director at SRS. “SWPF will be capable of annually processing six million gallons of salt waste from the more than 36 million gallons of radioactive waste currently stored at the Site. Adding the capabilities of the mixer pumps and SWPF to current liquid waste operations at SRS will sharply accelerate the waste tank closure activities at the DOE site.”

The mixer pump procurement initiative announced by SRR will ensure the salt waste material pumped from the tanks to SWPF is of the consistency to be processed in the salt processing facility.

To validate their work, the SRR-SRNL team has developed a prototype, scaled-down version of the proposed mixer pump. The one-tenth scale pump was placed in a similarly-sized waste tank to assist in the development of pump procurement specifications and observe if the pump operates as expected. When development of the design specifications is completed, the pumps will be procured in a competitive process with the contract for the pumps scheduled to be awarded by May 2010.

Materials processed through SWPF will be separated into a high activity waste stream and a low activity waste stream. The high activity waste stream will be converted into a glass form at the Defense Waste Processing Facility (DWPF) while the lower activity waste will be mixed with a concrete-like substance in the Saltstone Processing Facility (SPF) and stored in nearby vaults.

“SRR’s goal to be ready to feed when SWPF comes on line is crucial to meeting DOE’s expectation of closing waste tanks” said Keith Harp, project manager for the initiative, who added, “ARRA funding is critical for insuring we have the necessary infrastructure in place to accelerate our commitment to environmental cleanup at SRS.”