Staff Reports
WC Monitor
12/4/2015
Savannah River Remediation (SRR) is expected to postpone the need for a new, multimillion dollar waste building by double-stacking waste-filled canisters at Glass Waste Storage Building 1 (GWSB 1). SRR is the Savannah River Site’s liquid waste contractor and is charged with constructing and using multiple facilities to remediate 36 million gallons of high-level radioactive liquid waste stored in more than 40 waste storage tanks at the site.
The canisters stacked in GWSB 1 are filled with vitrified waste that was processed through the SRS Defense Waste Processing Facility (DWPF), which takes waste and a special glass form and heats the two products to create a molten glass. The final product is a waste form suitable for long-term storage at a repository. According to an SRS update in November, DWPF has produced 3,970 canisters of the waste form. To clear space for modifying the facility for double-stacking, workers have so far relocated 156 canisters of the classified waste from GWSB 1 to GWSB 2. The actual double-stacking of the waste canisters could begin as early as next year, according to SRR.
The method will modify the 2,254 storage slots in GWSB 1 and literally double the capacity of the building by allowing the slots to safely hold a total of 4,508 canisters. Each canister is 10 feet in height; to accommodate two canisters stacked vertically, the holding slots, which stand at 21 feet deep, will need to be modified, according to SRR. For example, the crossbar base support where the canisters rest will have to be removed. Also, a thick, concrete shield plug that guards against radiation will be replaced by a thinner, denser cast-iron shield plug, which will provide equivalent radiation shielding and structural support, according to SRR. The physical work to modify canister positions has begun, and the project will continue for another seven to eight years.
SRR President Stuart MacVean said that without double-stacking, production of additional waste canisters would come to a halt due to lack of space. "This double-stack concept keeps us processing waste, further reducing the risk of this waste staying in the tanks," MacVean said.
Double-stacking is expected to provide adequate storage through 2026. Storage at SRS is only a temporary solution as the nation searches for a federal repository to permanently store waste from SRS and other sites across the country. That location would have been Yucca Mountain – a Nevada site about 100 miles from Las Vegas. About $13 billion was spent on Yucca Mountain after DOE began drilling at the mountain in 1994 and President George W. Bush signed off on the repository in 2002. But that all changed in 2010 when President Barack Obama ordered work on Yucca to cease. Waste from three facilities – SRS, the Hanford Site, and the Idaho National Lab – would have been sent to Yucca. Together, they house nearly 24,000 canisters of glassified waste, with SRS holding 7,824 canisters.
