A watchdog group alleged Thursday that FirstEnergy intends to restart the Davis-Besse nuclear power plant knowing two of the reactor's four coolant pumps have flaws and are leaking.

The Nuclear Regulatory Commission is looking into the coolant pump allegations, an NRC spokeswoman said.

FirstEnergy disputes that any of the pumps have safety problems, a utility spokesman said.

Meanwhile, the plant'shoped-for restart date apparently will be pushed back to May from April, FirstEnergy spokesman Richard Wilkins said.

A reactor-coolant test is one of the last steps to be completed before the plant can be authorized to start, Wilkins said.

``We hoped to get all of the work done in April,'' he said. ``Maybe we will. It looks like it may slip into May.''

The NRC has final say on when the troubled power plant in Oak Harbor can be allowed to restart. It has been closed since mid-February 2002.

The NRC will not allow Davis-Besse to restart until it is sure the plant can be operated safely, agency spokeswoman Viktoria Mitlyng said.

The pumps, each of which is 14 feet high and weighs 50 tons, circulate coolant from the reactor to other huge devices known as steam generators.

It took 20 days, at a cost of $5 million, to repair two pumps, FirstEnergy said.

But FirstEnergy did not check two other pumps, even though the Akron utility knows those pumps are leaking as well, wrote David Lochbaum, the nuclear power expert for the Washington-based watchdog group Union of Concerned Scientists.

In addition to leaks, the pumps also may have other damaged parts, he said. He sent his complaint to the NRC.

The NRC must not letDavis-Besse restart with two flawed pumps, Lochbaum said.

Other nuclear power plants that discovered coolant leaks from similar pumps found that boric acid, which is part of the coolant, damaged nearby steel parts and equipment, Lochbaum said.

FirstEnergy spokesman Todd Schneider said: ``We will refurbish the other two pumps at an upcoming outage. Right now, they're in good operating shape.''

The issue of the flawed pumps was raised last month in a whistle-blower lawsuit filed against FirstEnergy.

Former Davis-Besse engineer Andrew Siemaszko said in his lawsuit that Davis-Besse managers opposed his July 2002 recommendation that all four pumpsbe repaired prior to restarting the plant.

The four pumps were reviewed by a team of engineers, Wilkins said. None showed an external leak, he said. At least one showed that an internal gasket was leaking, he said.

Lochbaum's complaint included documents showing that some of the pumps were leaking coolant as early as 1996, including some external leakage. Repairs apparently stopped external leaks.

An Aug. 9 company memorandum recommended that all four pumps be refurbished.

Amy Ryder, Cleveland director for Ohio Citizen Action, a watchdog group that has been trying to prevent Davis-Besse from restarting, said Lochbaum's complaint shows that FirstEnergy is putting production concerns over safety.

``Isn't this an issue where you err on the side of caution?'' she said. ``Are you erring on the side of safety, or are you erring on the side of production?''

It may cost FirstEnergy more than $400 million to repair Davis-Besse, including the cost to buy replacement power during its shutdown.

In March 2002, a safety inspection found that boric acid had created a large cavity extending nearly all the way through the top of the reactor vessel head that covers the radioactive fuel.

Both FirstEnergy and the NRC have said they share blame in letting the boric-acid damage take place for years before it was discovered.