By NICHOLAS K. GERANIOS

SPOKANE, Wash. (AP) — The U.S. Department of Energy’s inspector general on Monday said it could not determine if a whistleblower on the Hanford Nuclear Reservation was fired for raising safety concerns because two contractors failed to provide all the documents needed in the investigation.

Donna Busche was fired in February after raising questions about the safety of the unfinished Waste Treatment Plant at Hanford, the nation’s most polluted nuclear site.

Busche was a manager for URS Energy and Construction, Inc., which is a subcontractor of Bechtel National, Inc. in building the $13 billion plant.

The inspector general said URS and Bechtel would not provide several thousand emails and other documents necessary to determine if Busche was unfairly fired.

“We did not have access to the full inventory of documents which we felt were necessary to conduct our review,” the report said.

There was a fundamental conflict between the need of the Office of the Inspector General to have unfettered access to information and the desire of the two contractors to protect their legal interests in an upcoming lawsuit, the report said.

“This is exactly what we expected from URS and Bechtel,” Busche said in a statement issued through her attorneys. “These contractors have sent a clear message to any potential whistleblower at the Hanford complex; no one, including DOE, is more powerful that we are.”

Hanford, located near Richland, for decades made plutonium for nuclear weapons. The federal government is now paying more than $2 billion per year to maintain and clean-up the resulting nuclear waste.

The inspector general’s report said that Bechtel and URS both took the advice of lawyers to withhold some documents, either because of attorney-client or attorney work product privilege.

“Specifically, Bechtel withheld 235 documents and URS withheld 4,305 documents,” the report said.

URS eventually allowed access to a portion of the 2,754 withheld documents, the inspector general’s office said.

Bechtel issued a statement saying it was disappointed in the report.

“Bechtel went above and beyond in cooperating with the Inspector General’s investigation,” the company said. “Bechtel is committed to providing a work environment in which all employees are treated fairly and are able to raise concerns without fear of retaliation, and Bechtel expects its subcontractors to do the same.”

Tom Carpenter of the watchdog group Hanford Challenge said the inspector general should have ruled in favor of Busche.

“The Inspector General is rewarding contractors for refusing to cooperate,” Carpenter said.

U.S. Sen. Ron Wyden, D-Ore., a frequent Hanford critic, said it was unacceptable that the Energy Department’s inspector general could not obtain documents from the agency’s own contractors.

U.S. Sen. Claire McCaskill, D-Mo., demanded a briefing from the Energy Department no later than Oct. 31 regarding the contractors’ withholding of the documents and emails.

Busche has filed a federal lawsuit over her firing.

Bechtel and URS have denied that they retaliated against Busche. URS has said Busche was fired for reasons unrelated to the safety concerns.