The Savannah River Site’s Defense Waste Processing Facility (DWPF) resumed operations last week, ending a four-month scheduled outage that allowed workers to tie the $2.3 billion Salt Waste Processing Facility (SWPF) into the rest of the liquid waste system at the Department of Energy complex in South Carolina.
The DWPF is again treating radioactive sludge waste, which comprises 10% of the 35 million gallons of liquid waste stored in 41 Cold War-era tanks at the 310-square-mile site near the city of Aiken. The rest of the waste volume is salt waste that will be treated using the SWPF, which is expected to start operations in the first quarter of 2020.
The DWPF outage began on Aug. 1. Since the liquid waste system – which includes the tank farms, the defense waste facility, and waste storage facilities – is all interconnected, DWPF and other waste-related facilities had to be shut down so the salt waste facility could be connected. The outage allowed salt waste contractor Parsons to focus on connecting SWPF and testing the facility to ensure it could process salt waste.
Meanwhile, liquid waste contractor Savannah River Remediation (SRR) used the time to repair mercury pumps at the DWPF.
At any given time, about 60 metric tons of mercury is mixed in with liquid waste in the site’s tank farms and facilities. The toxic material is used as a dissolvent for reactor fuel during ongoing nuclear material processing operations at Savannah River’s H Canyon. When mercury is pumped out of the liquid waste system, it is recycled back to H Canyon for reuse. The DWPF initially accepts the material, then redirects it out of the system while processing liquid waste.
During the outage, Savannah River Remediation redesigned the plug for the pump and repaired severed pump lines. With the restart of DWPF operations, the contractor is also increasing the pH levels in the facility’s waste evaporator tank. Overall, non-labor cost of the mercury pump repairs and other minor equipment repairs during the outage cost about $250,000.
The Defense Waste Processing Facility converts sludge waste into less harmful, glass form suitable for interim storage at Savannah River.
