11/01/02

With two rounds of lab trials still unable to determine whether the bottom of Davis-Besse's reactor is leaking, FirstEnergy Corp. plans a much larger-scale test - taking the reactor up to operating conditions to see if any coolant seeps out.

The possibility of cracks and leaks in the nozzles that carry instruments up through the bottom of the reactor into the core emerged as a concern at Davis-Besse last month.

Before that, the Toledo-area plant had been dealing with cracks and leaks in the nozzles atop the reactor's lid, which led to a large rust hole.

The damage has kept the plant shut down nearly nine months and has prompted federal regulators and the nuclear industry to re-think how they deal with corrosion.

The seven-day power-up test, which the company wants to do in late December, involves reloading the fuel rods, bolting down the reactor's new lid, and turning on the coolant-circulating pumps. The pumps' heat and the natural decay of the radioactive fuel will bring the reactor to its normal operating temperature and pressure.

The control rods will remain in the core, however, preventing the nuclear reaction from starting, said FirstEnergy spokesman Todd Schneider.

After a week of simulated operation, the reactor will be shut down and its fuel removed. Inspectors will look underneath the reactor for any sign of the rust stains that initially triggered the leak fears.

Although FirstEnergy informed investors of its testing plans yesterday, the Nuclear Regulatory Commission has not yet approved the approach.

"We have not said, 'Yes, that's the thing to do,' or, 'No, it's not,' " said NRC spokesman Jan Strasma. "We expect there will be additional discussions on this and other possible options."

If leaks are found, FirstEnergy believes it can make repairs and stay on schedule to restart the plant early next year.

That presumes, though, that such cracks won't raise a new set of regulatory and research issues for the company to overcome. No utilities have ever found cracks in the bottom nozzles, where metal stresses are supposedly less because of the lower temperature there.

"We don't think we do [have leaks]," Schneider said. Instead, the company thinks the rust stains were caused by workers power-washing the rusty lid, or from runoff when the lid was removed for refueling. Though chemical tests couldn't trace the stains back to the lid, he said, the low level of radioactivity in them suggests that the coolant that caused the rust did not leak from the core through the reactor's base.

The corrosion that has scarred Davis-Besse's reactor continues to erode the NRC's confidence that 68 other similar reactors are rust-free. This week the agency ratcheted up the pressure on those plants to prove that they are doing thorough corrosion inspections in vital parts of the reactor other than the lid.

The NRC is unsatisfied with the plants' responses so far to a Davis-Besse-inspired bulletin this spring warning of corrosion danger and seeking assurances that the utilities are doing proper checks.

The agency's concerns are twofold: that it can't tell whether some operators are doing adequate inspections throughout their plants, and that the engineering code that guides inspections isn't thorough enough in light of Davis-Besse.

"Davis-Besse threw into question the efficacy of [corrosion] inspection programs," said Brian Sheron, the NRC's associate director for licensing and technical analysis. "We have confidence there are no plants with any kind of corrosion [on the lid] like Davis-Besse, but we want to . . . make sure the industry has a program in place so that we know there is not going to be corrosion" elsewhere.

To reach these reporters:

jmangels@plaind.com, 216-999-4842

jfunk@plaind.com, 216-999-4138