Two workers at the Department of Energy’s vitrification plant at the Hanford Site at Richland, Wash., were involved in a “near miss,” according to an August report more than a month after a jobsite evacuation triggered by a smoke alarm.
According to the Defense Nuclear Facilities Safety Board (DNFSB) report dated Aug. 1, the Low-Activity Waste (LAW) Facility at the Waste Treatment and Immobilization Plant had to be evacuated.
The smoke alarm was linked to the room that houses the uninterruptible safety power supply for one of the off-gas exhausters, according to the DNFSB report. The Hanford Fire Department responded and, after the crew determined things were safe, facility access was restored.
It turned out the smoke alarm was caused “by an arc flash event that occurred while workers were deconstructing a scaffold in the room,” DNFSB said in the report. “A metal plank, which workers were removing from the scaffold, bumped an electrical cable in an exposed cable tray while the plank was being handed from one individual to another. The impact caused a breach in the cable insulation, resulting in the arc flash.”
“This was a near miss for the two individuals handling the plank,” according to DNFSB.
For its part, contractor Bechtel National Monday said the company submitted additional information to DNFSB about the event and the board’s characterization of the incident as an arc flash. A Bechtel spokesperson said via email. Bechtel did an investigation and has implemented corrective actions, according to the spokesperson.
DOE and contractor Bechtel recently received an extension from Washington state, for the LAW facility to start making glass from some of the less-radioactive tank waste at the Hanford Site. The timeline was delayed from August to October.
The BWX Technologies-led prime contractor in charge of Hanford tank waste also held a week-long safety pause in July.