OAK HARBOR - FirstEnergy officials say they are well under way in fixing the damaged Davis-Besse nuclear power plant, but Nuclear Regulatory Commission officials say the utility will have to pass a thorough review before the reactor is allowed to power up.

In a lengthy meeting Tuesday afternoon with NRC officials before about 130 people at Oak Harbor High School, First-Energy executives outlined the steps they are taking to upgrade and repair the plant, shut down since mid-February. They also suggested changes in how the plant is managed to ensure its safe operation. The utility says it is on track to have the plant ready to restart sometime before the end of the year, providing it passes an NRC checklist.

The NRC outlined that checklist for the first time Tuesday, specifying exactly what FirstEnergy has to do to prove to the regulatory agency that the plant is ready and will be operated safely.

Davis-Besse was shut down after a safety inspection found a boric-acid created cavity on top of the steel reactor vessel head, a crucial safety device that covers the radioactive fuel. Critics have said the cavity, if it had not been discovered, could have caused a loss-of-coolant accident that might have released radiation into the environment. No radiation was released.

FirstEnergy bought a replacement vessel head from a never-operated reactor in Michigan. The replacement part will arrive at Davis-Besse, likely by truck, by Aug. 1, executives said. The radioactive fuel rods have been removed from the Davis-Besse reactor and stored elsewhere on the property, which overlooks Lake Erie in Oak Harbor, about 25 miles east of Toledo. Replacing the vessel head will mean a hole 20-feet-by 20-feet will have to be cut into the massive containment chamber composed of concrete and steel that surrounds the reactor.

In addition, FirstEnergy will do inspections to make sure microbial-induced corrosion isn't present inside the containment chamber, officials said.

The Washington, D.C.-based Union of Concerned Scientists, which has taken a skeptical look at how the NRC and FirstEnergy are investigating the Davis-Besse damage, on Monday sent a scathing letter to the NRC, criticizing both parties and calling for independent verification of inspections and repairs. Among other things, the organization said FirstEnergy and the NRC hadn't adequately addressed whether untreated water containing bacteria had seeped into the containment chamber, which could create extensive corrosion. In addition, the organization charged that FirstEnergy staff and management missed obvious signs over the years that something was amiss with the reactor.

``Our reviews continue to suggest that FirstEnergy failed to fully evaluate the safety significance of non-conforming conditions at Davis-Besse and that NRC inspectors repeatedly accepted incomplete evaluations,'' wrote David Lochbaum, nuclear expert for the Union of Concerned Scientists.

Lew Myers, the newly hired chief operating officer for First-Energy Nuclear Operating Co., said the company has created an independent ``Restart Overview Panel'' made up of FirstEnergy executives, retired NRC and Davis-Besse personnel, the Ottawa County administrator and others to look over the shoulder of the repair efforts.

``Until we get them satisfied, we won't start up,'' Myers said.

Because of that, Myers said he doesn't think the panel requested by the Union of Concerned Scientists and other anti-nuclear groups is needed.

Myers called Lochbaum an honorable man, but said ``maybe he doesn't fully trust what we're doing.''

Myers also said the company understands that its mismanagement caused the problems that led to the creation of the cavity.

``It's hard to sit up on a stage and call your baby ugly,'' Myers said. But FirstEnergy is taking steps to make sure that all employees adopt questioning attitudes and not look for easy answers to problems, he said.

``You will regain our confidence based on the quality of the work you do,'' said Jack Grobe, the NRC official who is the chairman of the panel overseeing the Davis-Besse investigation.

The key issue to the NRC approving the restart of the power plant is assurance that Davis-Besse will be run safely afterward, Grobe said.

The NRC sponsored a second meeting Tuesday night at the high school for the public to ask questions about what's happening at Davis-Besse.