The Nuclear Regulatory Commission staff might have let a power company's financial concerns influence a decision to put off a shutdown of the Davis-Besse nuclear plant, according to three watchdog groups.

But the NRC and FirstEnergy Corp. denied the allegation.

Akron-based FirstEnergy is paying about $200 million to repair the plant, install a new lid and buy replacement power until it is restarted. The reactor, about 20 miles east of Toledo, has been shut down since Feb. 16.

Inspectors found violations of 10 federal regulations at Davis-Besse, where acid nearly ate through a 6-inch-thick steel reactor cap. An NRC report released Thursday said FirstEnergy failed to take action to correct multiple safety concerns and violated rules for operating the reactor.

The agency is also continuing to study whether FirstEnergy should be charged with crimes, such as willful deception.

Workers have removed a damaged reactor head and are replacing it. The company wants to restart the plant by the end of the year, but regulators have given no indication when they will allow it to operate again.

The NRC is not supposed to consider the financial impact on nuclear plants when making safety decisions. The Plain Dealer reported that three nuclear power watchdog groups -- the Nuclear Information and Resource Service, the Union of Concerned Scientists and Greenpeace -- made the cost consideration charge Thursday based on newly released NRC documents obtained through the Freedom of Information Act.

The documents do not prove the NRC took costs into consideration, but ``it's a strong circumstantial case,'' said UCS engineer David Lochbaum.

The information included an e-mail dated Nov. 21 between two technical advisers to the NRC commissioners. The e-mail recounted a conversation that Samuel Collins, the NRC's senior safety officer, had with Robert Saunders, president of FirstEnergy Nuclear Operating Co., which runs Davis-Besse.

At the time, FirstEnergy was trying to convince the NRC that Davis-Besse should not have to shut down by Dec. 31 for an inspection. FirstEnergy wanted to keep Davis-Besse running until March 31 for refueling.

FirstEnergy ``does not want an order,'' the document summarizes from the Collins/Saunders conversation, citing the company's concerns about public perception, its inabilityto get its fuel delivered any sooner than February and the shutdown order's impact on ``financial markets.''

Collins, through a spokeswoman, said that FirstEnergy's cost concerns did not come into play, although the ``availability of equipment and personnel to do the inspections'' was a factor.

He said the NRC believed DavisBesse was safe to operate until Feb. 16, the compromise shutdown date the agency and the company negotiated.

FirstEnergy spokesman Todd Schneider said Thursday night that late last year Saunders ``certainly wasn't aware there was a cavity in the reactor head. He was operating with the best knowledge he had at the time.''

Schneider said that Saunders recalls making remarks at a public meeting that if FirstEnergy had to shut down Davis-Besse in December, that ``the company wasn't prepared to do that because fuel was not on site.''

Saunders' other concern was that one shutdown for inspection and another later for refueling might ``double the (radiation) exposure rate to employees,'' the spokesman said

He said Saunders ``doesn't know about any private conversation or e-mail'' that may have sought to influence the NRC through cost considerations.