The number of equipment leaks awaiting repair in Building 9212 – the main processing center for bomb-grade uranium at the Y-12 nuclear weapons plant in Tennessee – has been reduced from 120 in 2010 to a current level of 47, thanks to a “continuous effort to repair new and previously identified leaks.”
That’s according to a recently released report, dated May 9, from staff of the Defense Nuclear Facilities Safety Board.
Despite those improvements, leaks remain a problem at Y-12’s aged uranium processing center, with at least two recent incidents in which workers received skin contamination from uranium solution.
The report said in one instance a “drop of process solution” dripped from overhead onto an engineer’s forearm in the C-1 Wing of Building 9212. The safety board’s weekly activity report from Y-12 noted that even though the non-destructive assay engineer was wearing protective clothing appropriate for the task, the acidic solution soaked through the nylon cloth and made contact with skin.
According to the report, the first attempt to remove the radioactive contamination wasn’t completely successful, requiring a second effort that “reduced the (radiation) readings to less-than-detectable levels.”
The drip of uranium solution reportedly came from the connection between a drain valve and a section of tubing.
The DNFSB report also noted that a “separate but similar event,” involving a maintenance worker on a scaffold in the B-1 Wing of 9212, resulted in some “discoloration” on the forearm of his protective coveralls. “With the support of radiological control personnel, the worker doffed his PPE (personal protective equipment) and discovered skin contamination on his forearm,” the report stated.
In that incident, the contamination levels were reportedly lower and easier to remove than the other incident at 9212.
The defense board staff said, “Corrective actions will be formulated upon completion of the CNS (Consolidated Nuclear Security, the Y-12 contractor) fact-finding meeting for this event.”
The report described the leaks as an ongoing problem at the deteriorated 9212 complex at the Oak Ridge plant.
“Building 9212 is 71 years old and the processing equipment requires continuous maintenance to keep it operating safely,” the safety board staff wrote. “CNS Facility Engineering personnel have closely tracked and pursued repairs of identified leaks.”
The reported noted that the Y-12 contractor would evaluate the “adequacy” of the personal protective equipment worn by workers in the C-1 and B-1 wings of 9212.
Also, one of the leaking valves is to be fixed during a July outage being planned in support of an initiative at Y-12 to increase the production of purified uranium metal.