06/04/03

Port Clinton- Despite numerous unresolved engineering issues at the idled Davis-Besse nuclear power plant, a top official yesterday said plant owner FirstEnergy Corp. believes the reactor will be ready to start making electricity by early to mid-August.

"We feel solid about the first part of August," Lew Myers, chief operating officer of the company's nuclear division, told the special Nuclear Regulatory Commission panel overseeing repairs at Davis-Besse.

The NRC has the final say, however, and at the conclusion of the monthly meeting with FirstEnergy officials at the Camp Perry Ohio National Guard base near the plant, panel members characteristically gave no indication what they will recommend about the plant's future.

Issues still unresolved include:

High-pressure pumps designed to force water back into the reactor in the minutes following a major accident in which super-heated coolant blows through a broken pipe, valve or other reactor part must be modified or replaced. Engineering studies have revealed a modification that Davis-Besse made 15 years ago has made the pumps vulnerable to clogging by debris created by such a leak accident. The company is proposing to ship the 6,000-pound pumps to a Pittsburgh pump manufacturer to have "self-cleaning" filters installed inside the pumps. French reactors made similar modifications years ago.

The electrical distribution system may overload and not provide emergency equipment enough voltage during certain accident scenarios, a new Davis-Besse engineering analysis has revealed. Engineering director Jim Powers said the overload is predicted to occur only in one scenario. The company is proposing to install electrical relays to turn off power to certain equipment in order not to starve crucial equipment during emergencies. Both the engineering and actual work must pass NRC approval.

Existing electrical relays that send power to safety equipment were replaced with new switches, which turned out not to meet original plant specifications. Because the original relays are no longer manufactured, Davis-Besse engineers are testing the old switches and reinstalling those that still work. Extra old-style relays have been purchased from spare supplies of other plants, Powers said.

The room in which the plant's two enormous emergency generators are housed can overheat and possibly damage electrical switches on hot days, a new company engineering analysis shows. Powers said the diesel's exhaust manifolds will be insulated, electrical cabinets ventilated and large fans installed. But even with those modifications, engineers project the room could heat up to 134 degrees on a 95-degree day. The plant's technical specifications set 120 degrees as the highest temperature. Powers said the specs will probably have to be modified to reflect the shortcoming.

Some valves that are turned on and off by air pressure are not closing in the required amount of time. The company is fabricating new parts to meet specifications.

In July, if these engineering issues are resolved, plant officials plan a crucial pressure test of the reactor to determine whether tubes that pass through the bottom of the giant steel reactor are cracked and leaking. Residues found on the bottom last summer showed the tubes could have been leaking. A Texas company recently confirmed its reactor has bottom-tube leaks, the first in the nation.

Davis-Besse workers will conduct the pressure test by turning on the reactor's four 9,000-horsepower pumps to circulate the reactor coolant for a week. That will heat up the coolant to about 85 percent of its 600-plus degree operating temperature and to a normal operating pressure of more than 1 ton per square inch.

What happens afterward is still being discussed. The company wants to use a video camera to check for boric acid residues. And if the white powder is seen, it will check for lithium with a special chemical wipe. Both chemicals are present in reactor coolant, and their presence on the outside of the reactor bottom would prove a leak.

Though the lithium test is far more sensitive, the company is proposing to use it only if boric acid is spotted. Panel Chairman Jack Grobe earlier wondered why the lithium check would not be used even if boric acid is not found. Yesterday, he said the agency is reviewing the company's proposal but has not yet ruled on it.

There are also human performance issues.

For example, Davis-Besse must explain how workers flooded part of the plant last month when they were filling a circulating water system, said Grobe. The accident could indicate carelessness. The workers began filling the system without checking whether the drain valves were closed, said resident NRC inspector Scott Thomas, and flooded a large area to a depth of about 3 inches. FirstEnergy's Myers promised a report in July.

The company also revealed yesterday that it plans to conduct employee surveys to measure "safety culture" for two years after Davis-Besse restarts. NRC panel Vice Chairman William Ruland wondered why the surveys are not planned "for the life of the plant."

"It is not something that we require," Ruland said later. "But we do require them to operate the plant safely. This is something we have to look at very carefully."