Energy officials told a Senate committee on Tuesday that they were not asked to and did not approve the firing of Busche, who had raised safety concerns on the Hanford site.
Busche has filed a federal lawsuit saying she was fired in February because she raised issues about the safe operation of the unfinished waste treatment plant. They were some of the same issues raised by Walter Tamosaitis, a former manager on the project who was laid off in 2013.
The Tri-City Herald reports that if the Office of Inspector General concludes that Busche was fired in retaliation for raising legal issues, an Energy Department official says the agency will take action.
Hanford contractors Bechtel and URS have denied that they retaliated against the whistleblowers.