A small amount of hydrogen gas trapped in a pipe ignited in a brief, six-inch flame late last week when workers cut into the pipe, an Energy Northwest spokesman said.
There were no injuries nor equipment damaged in the incident in the “puff,” which lasted less than a second, said Energy Northwest spokesman Mike Paoli. Still, the Columbia Generating Station declared an “unusual event” and temporarily evacuated the immediate area. Plant officials also notified the Nuclear Regulatory Commission (NRC).
The pipe is in the plant’s main turbine building, which is a non-nuclear area, Paoli said. “There’s no association whatsoever with the reactor building or radiation,” he said.
The plant is on the Hanford nuclear reservation in south central Washington.
An “unusual event” describes a condition at a commercial nuclear power plant that could potentially compromise normal safety levels, Paoli said.
The Columbia Generating Station began a scheduled refueling outage one day before the incident.