Independent investigators are onsite at the Northwest’s only nuclear power plant, the Columbia Generating Station, north of Richland, Washington.

Plant operators say the reactor, run by Energy Northwest, a public agency that provides energy through the Bonneville Power Administration, is operating safely. But there is concern over accusations lobbed in an anonymous letter penned by possible plant employees.

Monday, the plant’s governing board might decide to expand the investigation.

In January, an anonymous letter penned by an apparent Energy Northwest plant insider – reached the agency’s executive board. It contained serious allegations. The letter said that the current CEO is inflating or hiding the true performance and safety of the plant. And that the plant’s managers are sacrificing workers’ safety by “stay[ing] on line at any cost.”

Energy Northwest’s Carla Martinez said initial findings of the investigation should come out by mid-March. The federal government’s Nuclear Regulatory Commission refused to give further details for this story, saying the matter was, “under review.”