It's all about cracks.

Cracks in metal.

Cracks in safety procedures.

Cracks in the enforcement of safety laws.

And cracks in public confidence.

In the year since theDavis-Besse nuclear reactor was shut down for repairs, thousands of hours of investigation have revealed numerous cracks in the systems designed to keep the public safe from a nuclear disaster.

The thousands of pages of investigations, studies and routine reports now make it clear that Akron-based FirstEnergy Corp.'s rusty old reactor at Oak Harbor was a lot closer to bursting than either the company or the Nuclear Regulatory Commission originally understood.

And month by month since March 5, 2002, when workers found acid damage that led to the discovery of a pineapple-size hole in the reactor's top, the company and the NRC have had to accept more blame for failing to detect the problem.

Consider what the past year has revealed:

• The NRC has admitted it did not have enough properly trained inspectors at the plant and did not see all the potential danger from boric acid leakage.

• FirstEnergy has admitted that its managers put profit ahead of safety.

• The company uncovered another safety flaw that heightened the risk of a meltdown -- possibly contaminating much of Northern Ohio -- although that risk of a meltdown was considered remote.

• Both the NRC and First-Energy admit that evidence of a problem had been accumulating at Davis-Besse for years. But no one was able to gather all the information and put it together.

How close Ohio came to a nuclear accident is a matter of debate -- although the NRC and industry experts call what happened a ``near miss.'' The loudest critics say that Davis-Besse almost cost us Lake Erie and threatened lives across the region.

Defenders of nuclear energy point out that the problems were discovered and the plant was shut down before such a failure occurred, proving how robust and redundantly safe these power plants are. No radiation was released.

Acting NRC Chairwoman Greta Joy Dicus said: ``We mighta, shoulda caught it sooner. But we did catch it.... there was not an event. There was not a loss of containment. Our defense in depth worked.''

In any case, all admit that the record reveals a need for greater diligence.

``Nobody wants to be the next Davis-Besse,'' said David Lochbaum, a nuclear power expert for the watchdog group Union of Concerned Scientists. ``I would hope we would not be seeing anything like Davis-Besse anytime soon.''

What remains to be decided, as the company hopes to restart the plant in April, is what must be done to fill the cracks in the oversight system and culture at Davis-Besse.

The NRC's Dicus said her main concern is to be as sure as possiblethat no ``smoking gun'' waits to be discovered at any of the nation's 102 other commercial nuclear power plants.

Worst-case scenario

The first cracks to come to light concerning Davis-Besse were in the form of hairline fractures in some of the 69 fuelcontrol-rod nozzles that run through the massive steel vessel head that sits atop the reactor.

Those cracks had allowed boric acid to leak from the reactor's cooling system and eat a cavity all the way through more than 6 inches of carbon steel that makes up the vessel head. Just a 3/8-inch-thick inner layer of stainless steel held back the high-pressure, 600-degree water inside the reactor.

That thin inner lining of stainless steel was bulging and cracking. A second, smaller cavity was also found.

Here's what could have happened if the larger hole had not been found:

• In another year or two, the NRC estimates, superheated coolant in the reactor would have jetted through the lining and into the surrounding containment chamber.

• An emergency sump system designed to collect and recirculate the coolant back into the reactor to prevent overheating was found to have been flawed from the day it was installed decades ago.

• If the sump had failed, a worst-case possibility would be that the reactor fuel would overheat, melt and then breach the containment chamber, releasing radiation into nearby Lake Erie and the surrounding area.

The stainless steel lining -- by luck, not design -- held the coolant inside.

Corrosion not dealt with

The first cracks in safety procedures came when Davis-Besse personnel and NRC inspectors failed over the years to ward off and detect this problem. Boric acid corrosion has been an issue in the nuclear power industry since the 1980s.

Boron is added to the reactor coolant water to help control the fission process, creating boric acid.

Wet boric acid can easily corrode carbon steel, which is why the reactor has an inner lining of stainless steel that is impervious to the acid. Dry boric acid, which is a white powder, wasn't believed to corrode carbon steel.

Davis-Besse personnel knew they had boric acid leaks -- they thought it probably had come from other parts of the reactor. What they say they didn't realize is that cracks in control-rod nozzles were letting coolant leak out on top of the vessel head.

Who knew what when at Davis-Besse, FirstEnergy and the NRC is still being disputed.

Hundreds of pounds of dry boric acid deposits were allowed to remain on top of the reactor head, even though the utility had told the NRC at one point that the head had been completely cleaned of boric acid.

Mere convenience and, possibly, cost appear to have been a big part of the reason the deposits weren't removed. The design of the Davis-Besse vessel head made it difficult to fully inspect and clean. Plant management in the early 1990s overruled its staff's recommendation that it make modifications that would have made cleaning and inspecting much easier.

When the area was inspected, boric acid deposits were seen but were allowed to remain because they were not considered dangerous.

``They left boric acid on top of the vessel head for several operating cycles,'' said Alex Marion, director of engineering for the industry-funded Nuclear Energy Institute. An operating cycle is about two years.

Industry and NRC guidelines and rules required the company to remove boric acid, and Davis-Besse didn't, Marion said.

FirstEnergy had video and pictures of boric acid accumulations on top of the vessel in the late 1990s. At least one of those pictures depicted rust-colored, not white, boric acid deposits running down the side that should have alerted someone that carbon steel was being corroded.

However, the NRC said red boric acid deposits weren't shown in photographs and videotapes that FirstEnergy provided during negotiations in 2001 to postpone a mandatory shutdown and safety inspection to look for nozzle cracks.

An NRC inspector stationed at Davis-Besse knew about boric acid deposits on the vessel head in the spring of 2000, but he never reported the finding to his superiors and didn't do a follow-up inspection.

NRC inspection problems

Personnel changes and staffing problems also added cracks in the safety shield at Davis-Besse, NRC documents show.

Over the years, Davis-Besse reduced its engineering staff by almost 60 percent from 1991 to 2001, from 218 to 123. That led to fewer people having to do more work at the plant.

The NRC also reduced its inspection hours at Davis-Besse. The agency typically has two resident inspectors at each nuclear plant. But the NRC had just one inspector at Davis-Besse for almost a year, from November 1998 to October 1999.

And the inspectors the agency did put in place were not always fully trained when they started. Doug Simpkins went to Davis-Besse as an NRC inspector in November 1999 and received his final certification for that job nine months later.

``Simpkins stated his first few months at Davis-Besse were spent trying not to get lost or set off alarms,'' an interview transcript from the NRC's Office of the Inspector General shows. ``He said because of this, he was `fairly clueless' about what was going on at the plant.''

But the longer Simpkins worked there, the more he began to understand the plant's conditions, the transcript shows.

In early 2000, two years before the shutdown, Simpkins learned that Davis-Besse personnel were concerned about red material from boric acid corrosion showing up in reactor filters. Simpkins also told the Inspector General's office that the NRC inspection program constrained him from pursuing the issue. A transcript of that interview says that Simpkins believed ``he did not have the freedom to follow his nose.''

Both FirstEnergy and the NRC later said that filters clogging from rusty boric acid should have tipped them off that something was amiss with the reactor.

Simpkins said that in 2001, a year before the shutdown, he asked the plant's systems engineer if the boric acid could be coming from the reactor head, but that engineer said the head had been inspected and it was clean, according to the transcript.

But it couldn't have been clean. Experts say the damage occurred over at least six years.

Bill Dean, the vice chairman of the NRC panel that is monitoring Davis-Besse, said the NRC's oversight process depends upon the plant operators doing the right thing. ``Inspectors can only sample a small portion of what goes on. We can't be there, everywhere, all the time.''

NRC OKs shutdown delay

The NRC showed cracks in its judgment and in following its procedures.

Because of problems at other plants, the NRC became increasingly concerned about dangerous nozzle cracking and ordered inspections across the nation in 2001. Those inspections required that the plants be shut down, a costly proposition. FirstEnergy wanted to delay the inspection at Davis-Besse.

An NRC memo shows that FirstEnergy argued that shutting down Davis-Besse would cost the utility $35 million, and more if repairs were needed. But the NRC also knew that Davis-Besse's design put it among the plants most susceptible to nozzle cracks.

In late 2001, FirstEnergy executives persuaded NRC senior management to delay a safety inspection for the plant. The utility argued that the inspection could be done in the spring of 2002 when the plant was scheduled for a regular refueling shutdown.

Although some NRC staffers argued that keeping the plant open past Dec. 31, 2001, increased the likelihood of an accident, a compromise was struck that kept Davis-Besse powered up until Feb. 16, 2002.

The NRC violated its own rules in delaying the safety inspection at Davis-Besse, said Paul Gunter of the Nuclear Information & Resource Service.

Previously, NRC staff had drawn up a draft order to specifically force Davis-Besse to shut down by Dec. 31, 2001, for the inspection.

But senior NRC managers arbitrarily chose to dismiss the order, Gunter said. ``In doing so, they put at risk public health and safety,'' he said. ``The near miss at Davis-Besse is an indication the NRC bent over backward to accommodate a corporate agenda, and that agenda was prioritized over public safety.''

The NRC's Office of the Inspector General later concluded that the agency put FirstEnergy's profits ahead of public safety in allowing the plant to operate beyond Dec. 31, 2001.

Restoring confidence

Now FirstEnergy and the NRC are trying to fill the cracks in public confidence that theDavis-Besse incident has created.

Even though there was no accident, FirstEnergy found itself in crisis, and the NRC found itself embarrassed. Davis-Besse is the new poster child for anti-nuclear groups.

FirstEnergy originally thought the power plant would be shut down for just a month or two for repairs.

A year later, Davis-Besse remains closed, although First-Energy expects the 883-megawatt plant will be ready to restart in mid-April pending federal approval. The latest cost estimate: $375 million.

FirstEnergy finished loading 265,500 pounds of uranium fuel rods into the reactor last week, a major step toward a restart.

The corroded vessel head has been replaced. Also replaced are most of the plant's top managers.

One of the major upgrades at Davis-Besse is a much larger, state-of-the-art sump.

The company is furiously working to inculcate a greatly improved ``safety culture'' among all Davis-Besse employees to ward off the kinds of staff-performance problems that had allowed boric acid leaks to go unchallenged for years.

Gary Leidich, the new executive vice president for FirstEnergy's nuclear operating company subsidiary, calls what happened at Davis-Besse a ``serious near miss.''

FirstEnergy hired him last year as part of the management restructuring at Davis-Besse. Leidich is confident the plant will safely restart and operate.

For years, the industry and regulators considered Davis-Besse a reliable and safe plant, Leidich said. ``I think the whole industry was surprised by the extent of the corrosion,'' he said.

Now the lessons learned at Davis-Besse will help the rest of the nuclear industry operate more safely, Leidich said.

Likewise, the NRC has undergone internal investigations to figure out why it failed for so long to uncover the plant's woes.

Also, the NRC's Office of Inspections is conducting a criminal investigation into whether FirstEnergy deliberately withheld information or provided misleading information about the plant's condition. Congress' nonpartisan investigative arm, the General Accounting Office, is also looking into the plant and the NRC.

An NRC group has reviewed lessons learned at other reactors and compared them with Davis-Besse's findings. ``There were quite a few that were repeats. That's not a good sign,'' said Lochbaum of the Union of Concerned Scientists.

All this scrutiny is supposed to make the nuclear industry safer and the NRC more effective. FirstEnergy and the NRC say they will not allow Davis-Besse to restart until they are sure it will operate safely.

Whether they have filled in all the cracks in oversight and reporting that took the plant so close to the brink remains to be seen.