The Waste Isolation Pilot Plant should have reported a Jan. 23 incident, where two miners were stuck up to 30 minutes in a waste hoist lowering them underground, to the Department of Energy’s accident reporting system, a federal safety watchdog says.
“Site personnel determined that an erroneous digital signal caused a breaker to trip, resulting in a complete loss of power” to a man cage that had lowered two miners 1,500 feet below the surface, according to the Defense Nuclear Facilities Safety Board (DNFSB) staff report posted recently.
Within 30 minutes of the issue developing, Waste Isolation Pilot Plant (WIPP) operators “successfully lowered the cage to the underground,” according to the report.
The DNFSB staff “consider a loss of hoist control due to the power outage to be an unsafe condition that was properly mitigated by the credited braking system,” according to the DNFSB document. “It appears that this event should have been reported” in the Occurrence Reporting and Processing System.
Bechtel’s Salado Isolation Mining Contractors “contend that it was not due to an actual unsafe condition because food, water, and an eventual escape through dynamic lowering could have been made available to the miners,” DNFSB said.