Brian Bradley
WC Monitor
10/23/2015
Savannah River Site workers recently relocated 156 canisters of glassified waste from Glass Waste Storage Building (GWSB) 1 to GWSB 2, starting the modification process for double-stacking canisters at the site and potentially opening the possibility for actual double-stacking to begin in 2016, SRS said in a press release on Tuesday. Developed by SRS liquid waste contractor Savannah River Remediation, the concept involves modifying GWSB 1’s existing canister storage positions, which can each hold one canister, into slots capable of accommodating two vertically stacked canisters. The modifications are aimed at creating adequate interim canister storage through fiscal 2026, and could increase GWSB 1’s capacity from 2,254 slots to 4,508 slots, according to the release.
The canisters contain vitrified waste from the Defense Waste Processing Facility and are destined for storage at a federal repository. Engineering studies have shown that the stacking will pose “no technical or radiological issues” at SRS, the release states. Physical work on slot modifications is expected to start this month, and the project will continue for another seven to eight years, “as needed,” according to the release. “Without space to store the canisters, our production stops,” SRR President and Project Manager Stuart MacVean said in a statement. “This double-stack concept keeps us processing waste, further reducing the risk of this waste staying in the tanks.”
Double-stacking would also postpone the expense of building another storage facility, which is estimated to cost as much as $74 million, the release states. While 21-foot-deep slots each can accommodate one 10-foot-tall canister, those slots would have to be modified to admit two containers. Currently, each canister storage position has an elevated steel crossbar support base and a 4-foot-thick shield plug that seals the opening at the top of each canister’s slot. The crossbar base support, on which canisters sit, must be removed and the concrete plug will be replaced by a thinner, denser cast iron shield plug, which will provide “equivalent radiation shielding and structural support,” the release states. Along with the cast iron shield plugs, steel-support plates will be installed to replace the crossbar base support.
“At DOE, we want to see safe, creative solutions to solve issues,” Jim Folk, Energy Department-SR assistant manager for waste disposition, said in a statement. “Finding this new method for canister storage is a game-changer in terms of finding new storage space that will save millions of dollars.”
