Savannah River Site (SRS) liquid waste contractor Savannah River Mission Completion (SRMC) recognized a team of more than 200 employees for modifying all storage positions in Glass Waste Storage Building (GWSB) 1 for the purpose of double-stacking canisters.

The entire team involved in the project’s success marked the completion with a recognition event featuring speakers from SRMC and Department of Energy-Savannah River (DOE-SR) leadership.

Jim Folk, DOE-SR assistant manager for waste disposition, said the double-stack concept is one that DOE believed had significant potential to save taxpayers more than $100 million.

“The concept itself is simple and needed,” Folk said. “This engineered approach of double-stacking canisters eliminates the need for additional buildings and infrastructure, saving both time and money. These types of improvements pave the way for the Liquid Waste Program to accelerate waste removal and tank closure.”

The canisters are produced at the Defense Waste Processing Facility, the only operating radioactive waste glassification plant in the nation. This facility, which began radioactive operations in March 1996, uses a vitrification process to convert high-activity radioactive liquid waste stored at SRS into a solid glass form suitable for long-term storage and disposal. Once filled at DWPF, the canisters are transported to one of the nearby GWSBs.

GWSB 1 began accepting filled canisters in 1996, and GWSB 2 received its first canister 10 years later. In 2015, the existing design of GWSB 1 was re-evaluated and determined through several studies that, with some minor modifications to the shielded storage plug and removal of the canister support crossbars, a second canister could be safely stored on top of the first. The canister double-stack project began in 2016 as an innovative method to increase onsite storage capacity of vitrified high-level waste canisters without construction of an additional facility.

To modify the positions, Construction employees developed and implemented a remote cutting tool that removed the existing canister support crossbar at the bottom of the position. The original four-foot-thick concrete plug used to insert into each storage position has been replaced with a two-foot-thick cast iron plug designed to provide comparable structural and radiological shielding protection. Each storage position in GWSB 1 is 21 feet deep. These modifications provide additional vertical space for each storage position.

GWSB 1, an underground vault for temporary storage of canisters, was designed to hold 2,262 canisters. With all positions modified, the facility now has space for 4,524.

SRMC Chief Operations Officer Wyatt Clark praised the level of cooperation demonstrated across the liquid waste program.

“This is the textbook definition of teamwork,” Clark said. “Each time a significant project is placed before us, our teams collaborate and get it done. From our initial discussions with DOE, to the workers in the field who are making it happen, these cooperative partnerships are both productive and beneficial for everyone involved.”

Ken Wells, operations director of the SRS Defense Waste Processing Facility, said the collaborative effort by workers made the idea of canister-stacking a reality.

“This project required the unique efforts of each of the individuals and groups involved,” Wells said. “From Engineering and Procurement to Radiation Control and Construction, the list goes on. But it was the innovation and across-the-board coordination that made this project happen.”

Work has begun to provide double-stack capability in GWSB 2 which, if fully modified, will expand the building to hold 4,680 canisters. The double-stack work in both GWSBs is expected to provide the storage space necessary to complete the SRS liquid waste mission.

SRMC comprises parent company BWX Technologies, Inc. with partners Amentum and Fluor. Its team brings the capabilities necessary to accelerate cleanup at the U.S. Department of Energy’s Savannah River Site through safe nuclear operations, optimized and integrated mission execution, and strong corporate governance.