Nuclear Pollution

NRC: Richland, WA, nuclear power plant workers exposed

Some workers at the Columbia Generating Station received unexpected and significant exposure to radiation during the spring maintenance and refueling outage, according to the Nuclear Regulatory Commission.

Exposures could have been higher, had a problem not been discovered promptly by chance.

But “no credit is given for luck,” said the NRC in its inspection report.

The NRC is considering issuing a “white” violation finding to Energy Northwest over the incident at its nuclear power plant near Richland, Wash.

A white violation, the lowest second on NRC’s four-step color scale, has low to moderate safety significance and can lead to an additional NRC inspection to make sure issues have been corrected.

The incident happened on May 28 when the commercial nuclear power plant, the only one in the Northwest, was shut down for planned maintenance. It was shortly before Brad Sawatzke, then chief executive, officially retired.

Radiation workers and pipefitters on the night shift May 28 were preparing for welding on piping of the highly contaminated reactor water cleanup heat exchanger, according to an NRC inspection report.

After the pre-job briefing, a radiation protection technician was unable to get on the work platform attached to scaffolding and left to find another technician to fill in. The technician who filled in had not attended the briefing and arrived after workers already were cutting into a pipe.

The work on the pipe, including grinding, required using an enclosure glove bag to contain any radioactive particles that might become airborne.

But workers used the wrong glove bag inlet attachment, and the glove bag collapsed when a vacuum system was turned on. Workers turned off the vacuum system, which allowed airborne radioactivity to collect and escape when the glove bag was removed, according to the inspection report.

Fortunately, a radiation protection technician happened to be watching work on video surveillance cameras.

He immediately spotted the issue and within 30 seconds was in the room and had ordered work stopped.

Radioactive contamination was found on the faces of two pipefitters, leading to the evacuation of 20 more workers in the room.

One pipefitter was found to have an internal dose of 961 millirem and the second had an internal dose of 711 millirem.

The NRC limits exposure to 5,000 millirem per year for both external and internal radiation, and Energy Northwest sets a more conservative limit of 2,000 millirem.

One radiation protection technician received an internal dose of 14 millirem. Eighteen other workers had unintended uptakes of less than 1 millirem after passing by the area of ​​the airborne radioactive particles as they evacuated the room.

Columbia Generating file.JPG
Energy Northwest’s Columbia Generating Station near Richland, Wash., is the Northwest’s only commercial nuclear power plant. Tri-City Herald file

NRC: Workers exposed

Energy Northwest failed in several ways to provide adequate radiological controls for the work, according to the NRC report.

It said Energy Northwest was fortunate that the radiation protection technician happened to see the work on a remote monitor, had enough experience to recognize a problem and was only 40 feet away from the room.

Had the pipefitters remained in the room for another five minutes, they could have been exposed to more than 5,000 millirems, exceeding the NRC annual limit, the inspection report said.

Energy Northwest should have done more radiation surveys the day before work started, should have prevented airborne radioactive particles and should have had a radiation protection technician with the two pipefitters at all times.

Energy Northwest has conducted an investigation and taken actions to prevent similar problems occurring from again, it said.

The NRC will hold a regulatory teleconference with Energy Northwest officials at 7 am Pacific Time on March 1 to discuss the incident.

The public can listen to the business portion of the meeting and then ask questions by calling 800-857-5003 and entering passcode 5204033#.

The teleconference will be an opportunity for Energy Northwest and the NRC to discuss the circumstances of the incident and make sure the NRC has a full understanding of information before it makes a decision on a “white violation” occurred, according to Energy Northwest.

No decision is expected to be made during the teleconference.

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Senior staff writer Annette Cary covers Hanford, energy, the environment, science and health for the Tri-City Herald. She’s been a news reporter for more than 30 years in the Pacific Northwest.

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