The Y-12 National Security Complex had not cast any enriched uranium for national defense programs for about a week as of Friday, after an unspecified quantity of the fissile material leaked into casting machinery at the National Nuclear Security Administration plant in Oak Ridge, Tenn.
Casting furnaces at Y-12’s 9212 building — operated by the Bechtel National-led contractor Consolidated Nuclear Security (CNS) — melt enriched uranium so it can be molded into shapes that fit into nuclear weapons and reactors. A so-far-unidentified glitch in this operation deposited “small quantities of enriched uranium in process equipment,” a CNS spokesperson said by email Thursday.
Personnel halted all casting operations in Building 9212 on March 28 after discovering these uranium deposits. The material was removed from the bottom of the casting furnaces where it was discovered, but casting had not resumed as of Thursday, a CNS spokesperson said. Substantially all uranium processing at Y-12 happens in Building 9212.
Consolidated Nuclear Security would not identify the intended recipient of the uranium that was on the line when casting ceased, or say when operations might resume.
“Operations will resume when our analysis has been completed and additional controls identified and implemented,” the CNS spokesperson wrote.
Y-12 last paused casting operations at Building 9212 in 2016, when around 2 feet of water unexpectedly accumulated in the building’s ventilation system. Also in 2016, CNS discovered that uranium dust built up faster than expected in one of the vent system’s filters. There were no reports of excess uranium deposits in the casting furnaces at that time.
Building 9212 is a World War II-vintage plant that will be replaced by 2025 by the Uranium Processing Facility Bechtel is building under a subcontract to CNS. The new facility will use three buildings to perform the same tasks currently housed under one roof at 9212: a design the U.S. Energy Department’s National Nuclear Security Administration (NNSA) and its contractor believe will make uranium operations safer by confining the riskiest parts of the work, including casting, to one building, and performing comparatively simpler tasks, such as waste-handling, in another.
The NNSA in late March authorized construction on key parts of the Uranium Processing Facility, including the Main Process Building. The total bill for the UPF, including design and construction, will come to around $6.5 billion over 15 years, the agency said.
