A Savannah River Remediation employee uses a manipulator located inside a shielded enclosure at the Defense Waste Processing Facility, where a melter pours molten glass into a canister.
AIKEN, S.C. – The second melter to operate in the 16-year history of the nation’s largest radioactive waste glassification plant shows no signs of slowing after recently pouring its 2,000 canister of glass-formed hazardous waste.
The melter at Savannah River Site’s (SRS) Defense Waste Processing Facility (DWPF) is a 65-ton refractory-lined melting vessel that receives a chemically-balanced feed of treated high-level waste from the site’s underground waste tanks. A mixture known as borosilicate frit is used to remove contamination. When heated, these elements form a molten glass. The solid glass-formed waste is then poured into stainless-steel canisters, which are safely stored onsite until they can be placed in permanent storage. Each canister is 10 feet tall and 2 feet in diameter and weighs about 5,000 pounds when filled with the glass-formed waste.
Melter operations are vital to SRS liquid waste contractor Savannah River Remediation’s (SRR) mission to dispose of the site’s hazardous waste, SRR DWPF Treatment Project Director Steve Wilkerson said.
“The melter is the heart of the DWPF and keeping it safely operating is key,” Wilkerson said. “We continue to surpass performance milestones with the help of recent enhancements, such as the deployment of bubbler technology in the melter.”
The facility’s second melter began operations in 2003. Since achieving its 2,000th milestone, the melter has poured more than 30 additional canisters. The first melter poured 1,339 canisters over a seven-year period that ended in 2003.
SRR has achieved other production milestones as well. In December 2011, the second melter produced 37 canisters, the most ever in a month. In all of 2011, it poured 266 canisters, an annual production record.
With liquid waste operations continuing into the next decade, additional melters will be required. SRR has a third melter in storage, ready to operate when necessary. A fourth is under construction. SRR expects melters will need to pour a total of 7,557 canisters to dispose of SRS hazardous waste.
DOE Savannah River Operations Assistant Manager for Waste Disposition Project Terrel Spears said canister production is crucial to eliminating the site’s hazardous waste.
“Since beginning operations, DWPF has poured 14 million pounds of glass and has immobilized 40 million curies of radioactivity,” Spears said. “Every canister poured means less risk to people and the environment.”
Immobilizing some of the most hazardous waste in South Carolina is a focal point of liquid waste operations at SRS, according to Dave Olson, SRR President and Project Manager.
“By mixing the radioactive waste in a glass form, DWPF reduces the risks associated with liquid waste at SRS and is essential in SRR’s mission to clean and operationally close the site’s waste tanks,” Olson said.
The SRS liquid waste contract is managed by SRR, a team of companies led by URS Corp. with partners Bechtel National, CH2M Hill and Babcock & Wilcox. Critical subcontractors for the contract are AREVA, Energy Solutions and URS Safety Management Solutions.