AIKEN, S.C. – Twenty-five years ago this month, the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) began radioactive operations.

DWPF has been safely treating high-level tank waste at the EM facility since radioactive operations began on March 12, 1996. On April 29, crews poured the first radioactive canister. To date, more than 4,200 canisters have been poured at DWPF.

The only operating waste vitrification plant in the nation, DWPF is operated by Savannah River Remediation (SRR), EM’s liquid waste contractor at SRS. Operations are expected to continue at DWPF for approximately 15 more years, and about 4,000 more canisters are scheduled to be produced.

Vitrification is the process of using extremely high temperatures to turn radioactive high-level waste, combined with a sand-like material, into a glass form. A 75-ton melter is used to glassify the waste into borosilicate glass, which immobilizes it, and makes it suitable for safe, long-term disposal in stainless steel canisters. These canisters are safely stored in an on-site facility until a federal repository is identified.

DWPF’s history can be traced back before its 1996 startup. In the mid-1970s, DOE recognized significant safety and cost advantages in immobilizing the liquid waste into a solid form. About 20 different waste forms, including synthetic rock, ceramic, and cement, were evaluated as a solution to stable, long-term storage of the liquid waste.

In 1982, DOE selected borosilicate glass as the preferred waste form for the high-level waste at SRS. Research confirmed that the radioactive constituents in the waste were chemically bound in the borosilicate glass matrix, making it a highly durable waste form.

In November 1983, ground was broken for construction of DWPF. After construction was completed, the facility went through a rigorous startup testing program. Eighty canisters of simulated glass were poured during testing.

Jim Folk, DOE-Savannah River assistant manager for waste disposition, said the DWPF remains an important part of the SRS liquid waste system and to the EM tank waste cleanup mission.

DWPF was constructed of 71,000 cubic yards of concrete and 10,500 tons of steel. The 10-foot-thick concrete foundation mat is reinforced by 2¼-inch-diameter reinforcing steel.

Three different melters have operated as the “heart” of DWPF, melting and pouring the waste stream into canisters. Melter 2 poured more than 10 million pounds of glass and exceeded its design life by more than 12 years. Melter 3 has been operating since 2017. DWPF has poured more than 16 million pounds of molten glass since 1996.

Phil Breidenbach, SRR president and project manager, said DWPF has been a mainstay for the liquid waste mission for decades.

“The success of the Defense Waste Processing Facility, teamed with its counterparts, the Salt Waste Process Facility, the Saltstone Production Facility, and the tank farms, positions SRR to accelerate the mission at an even greater pace,” Breidenbach said. “This progress is due to the work of the entire DWPF team — past and present — for setting us up for success. Congratulations and thank you to DWPF and the team who has operated it for a very successful 25 years!”