Federal officials believe Energy Northwest's procedures may be inadequate for notifying workers at defunct plants Nos. 1 and 4 if an accident occurred at the nearby Columbia Generating Station.

The Nuclear Regulatory Commission has issued a yellow inspection finding, indicating a possible "substantial safety significance."

A yellow finding is the second highest of four classifications but not serious enough to warrant shutting down the 1,150-megawatt Columbia Generating Station.

It is Washington's only operating nuclear plant.

"It's not an urgent safety issue," said NRC spokesman Breck Henderson.

The NRC is scheduled to meet Monday in Texas to discuss its findings with officials from Energy Northwest, the 16-member public power consortium that owns the plants.

The findings do not relate to any activity inside the fence at Columbia. But from time to time, outside contractors and businesses bring workers to other parts of the nuclear site for various reasons. Contractors were recently on site, for example, to remove material from the partially finished cooling towers at Plant No. 1.

A brake drum manufacturer also is a tenant, a Hanford contractor occasionally sells surplus equipment at Energy Northwest and another company leased land at Plant No. 1 earlier this year to bring in temporary diesel generators.

The NRC believes procedures for notifying workers associated with those companies of an accidental radiation release at Columbia and follow-up plans for radiological monitoring are faulty.

"They were left out of the procedure," Henderson said. "They were not on the call list."

Energy Northwest maintains there always has been a plan for such workers but acknowledges it is guilty of an "implementation weakness."

The utility has sirens that cover all of the site and a public address system that reaches most of it, spokesman Don McManman said.

It also has procedures for notifying workers by phone, a chain of command responsible for ensuring workers leave the site and a plan for directing traffic off the site.

"We've got sirens you can hear for miles," McManman said.

Several additions to the plan already have been implemented, including giving security crews more responsibility to ensure proper evacuation.