Following a 14-month outage, liquid waste processing at the U.S. Energy Department’s Savannah River Site is expected to restart by the end of the April.
The South Carolina facility said in January operations would begin by March. But that milestone has been delayed by a month, Sonya Goines, DOE spokeswoman at Savannah River, said last week by email. “The schedule change was due to better understanding of how to implement revisions to the documented safety analysis,” she wrote, referencing the technical basis for ensuring safe and compliant operations.
The Savannah River Site reported in February 2017 that it had to replace the Defense Waste Processing Facility’s (DWPF) Melter 2: a 65-ton refractory-lined melting vessel that mixes high-level radioactive waste with borosilicate frit to form a molten glass that can be safely stored in stainless-steel canisters. The waste is temporarily stored at SRS, but will eventually be shipped away once the DOE identifies a permanent disposal facility.
The melter went down in February and was removed in May. Starting in February, SRS was forced to implement a site-wide liquid waste processing outage because it could no longer use the melter to transform the waste into glass. Operations were shut down for nearly the entire calendar year and through the first quarter of 2018.
The melter replacement cost $3 million.
The Savannah River Site currently stores more than 35 million gallons of waste – 10 percent sludge and 90 percent salt – in over 40 underground tanks. The waste is a byproduct of Cold War nuclear weapons operations at SRS. The DWPF is designed to process the sludge waste and some components of the salt waste.
The salt waste is treated using a pilot process that began in 2008. But in December 2018, the Salt Waste Processing Facility (SWPF) is expected to come online and elevate processing from 1.5 million gallons per year to 6 million annually.
Before the outage can end, Goines said workers must take a few other steps, such as conducting preventive maintenance of welder controls at DWPF.
The outage, despite its length, is expected to have no long-term impact on the schedule or cost of liquid waste processing, as such events are factored into the SRS Liquid Waste System Plan. Liquid waste cleanup could last until 2065 with a total cost somewhere between $91 billion and $109 billion.
Though the outage is ongoing, SRS has begun pouring waste into canisters following the installation of Melter 3. The melter change was completed on Dec. 29, and Melter 3 has been filling canisters with waste that was treated prior to the outage. To date, the new melter has filled seven canisters.
