The U.S. Department of Energy has ramped up downblending of a tranche of plutonium at the Savannah River Site in South Carolina, with work to increase further if the mission continues at a successful pace.
In November, site management and operations contractor Savannah River Nuclear Solutions (SRNS) increased operations to two 12-hour shifts per day, seven days a week, according to SRS spokesman Monte Volk. Another 30 workers were hired, joining personnel who were already employed by the contractor.
Previously, SRNS had conducted the downblending mission in single 12-hour shifts since the mission began in September 2016. Those shifts ran four days a week, Monday through Thursday.
The degree to which the change will expedite plutonium downblending was not immediately clear. “Original estimates were in the 40-50 percent range, in terms of increased throughput a year going to a fully supported two-shift operations,” Volk said. “Modeling and throughput estimates are still being worked as we collect additional processing data and experience.”
There are no cost projections for the November ramp-up, since the downblending mission falls completely under the SRS nuclear materials line item in the site budget. The budget line for the current federal fiscal 2019 is about $350 million.
If the faster pace of work proves successful, Volk said SRNS could further increase operations in 2021 – to four 12-hour shifts, seven days a week and 24 hours a day, with some shifts overlapping. If that happens, SRNS would hire another 90 workers for the mission.
There is no set total number of employees assigned to the downblending program, since most of the personnel on the project were already employed by SRNS and are working various other missions for the contractor.
The SRS plutonium downblending mission involves diluting 6 metric tons of weapon-usable plutonium currently stored at Savannah River. None of the material is part of the 34 metric tons of plutonium that was intended to be converted into nuclear reactor fuel through the unfinished Mixed Oxide Fuel Fabrication Facility, which DOE officially terminated in October.
Under the SRS downblending mission, plutonium is diluted at the K Area complex using inhibitor materials, converting it to a form that cannot be used to make nuclear weapons. The plutonium solution is stored for now at K Area. When the 6 metric tons are fully processed, the material will be shipped to the Waste Isolation Pilot Plant (WIPP) near Carlsbad, N.M.
Even with the increased workload, the downblending mission is expected to last until 2046, as increases in processing were baked in to the schedule.
Savannah River Nuclear Solutions to date has downblended 25.7 kilograms, or 0.0257 metric tons, of plutonium. That includes a five-month pause of operations from October 2017 to March 2018 to perform planned maintenance activities, along with work slowdowns because the same personnel had to work on other missions.
The plutonium was generated across the DOE complex during nuclear weapons production through the Cold War.
