A hole in a calibration valve caused the hydrogen fluoride leak that prompted the operations contractor of the Y-12 National Security Complex to evacuate the main U.S. uranium processing building in early April, according to a recent report by the Defense Nuclear Facilities Safety Board (DNFSB).
“Based on a visual inspection, a hole was identified in a calibration valve as a likely source of the leak,” the board said in a report released Friday. Y-12’s Bechtel-led management contractor, Consolidated Nuclear Security (CNS), “is evaluating options to repair the leak and safely disposition the hydrogen fluoride that remains in process.”
On April 4, an interior sensor on a piece of equipment in the dock area of the 9212 building at the Oak Ridge, Tenn., facility detected hydrogen fluoride where there should have been none. The sensor first sounded the alarm around 8 a.m. About 90 minutes later, personnel had completely evacuated Building 9212. They returned to work a short time later.
A spokesperson for the National Nuclear Security Administration (NNSA), the owner of Y-12, said “[t]he event resulted in no personnel exposure or injuries.”
Hydrogen fluoride is a gas that can cause serious skin burns, blindness, and damage to throat and lung tissue if inhaled.
Y-12 manufactures the uranium-fueled secondary stages for nuclear weapons. The site is now working on the B61-12 nuclear gravity bomb the NNSA is refurbishing. The first B61-12 canned subassemblies rolled off the line at Y-12 in December.
