05/07/03

Camp Perry - With a crucial leak test of the Davis-Besse nuclear reactor a few weeks away, FirstEnergy Corp. officials and federal regulators still have not settled how best to rule out whether there are cracks in the bottom of the thick steel vessel.

If the test next month produces no visible signs that there are leaks in some of the instrument tubes that pierce the bottom, the plant's operator says it sees no need to follow up with a more sensitive detection method that would rule out even the smallest seepage.

The Nuclear Regulatory Commission prefers using the confirmatory test - swabbing the reactor's steel base with wipes and analyzing them for minute traces of coolant - in addition to a visual leak inspection using a robotic camera.

FirstEnergy Corp. officials insisted yesterday that the visual check should be adequate, absent obvious clues like the lumps of dried coolant residue that would collect around a leakage site if there were cracks on the reactor's thick steel underbelly.

"We're not doing it" as an initial test, Lew Myers, FirstEnergy's nuclear division chief operating officer, said of the chemical swabs that the NRC favors. "We explained our position, and they seemed to understand it," Myers said after a meeting between the company and the NRC yesterday.

But as far as the NRC is concerned, the testing method is still open. "It's not resolved yet," said Jack Grobe, who chairs the special agency panel that is overseeing Davis-Besse's rehabilitation after workers 15 months ago found the consequences of a devastating leak in the reactor's lid. A pineapple-size rust hole had formed there.

Traces of rust have since been found on the bottom of the Toledo-area reactor, and both the NRC and FirstEnergy are trying to determine whether there might be a leak there as well.

One other reactor, in south Texas, confirmed a bottom leak last month. The NRC is closely watching the Davis-Besse test, since its outcome, along with further information from Texas, would help determine whether leaks in reactor bases might be a nationwide cause for concern.

Grobe said NRC staff members need to further analyze the testing options before deciding the most appropriate course. The leak test involves bringing the long-idled reactor up to its normal operating pressure and temperature for a week, but not allowing nuclear fission to occur in its core. The inspection would occur afterward. FirstEnergy says it's concerned with limiting the amount of radiation its workers would be exposed to when using the hand-held swabs under the reactor vessel.

Another matter that must be resolved before the bottom leak test is what to do about potential problems with some of the reactor's emergency cooling pumps. Intensive engineering reviews at the plant recently determined that two of the emergency pumps, which use high pressure to force water back into the hot core in the event of a small rupture, might not work in certain conditions. Debris from the rupture could foul the pumps' bearings, causing the equipment to seize up and fail.

FirstEnergy believes it can show that the pumps will work adequately to get through the weeklong test in June. Later, though, the company will either modify or replace the pumps. Yesterday, FirstEnergy proposed a modification that would add small, self-flushing strainers deep inside the pump to keep grit away from the bearings.

The solution hasn't been tried elsewhere, said FirstEnergy consultant Bob Coward, "but people assure us it will work."

While Davis-Besse's recovery from its leaking lid continues, another plant with similar problems encountered a setback over the weekend. The Oconee nuclear station in South Carolina had repaired cracks in two nozzles on the reactor lid several years ago, but it just found more signs of leakage at the repair site.

The NRC is closely watching Oconee, said Brian Sheron, associate director for licensing, who attended yesterday's Davis-Besse meeting. He said the agency is also watching the St. Lucie nuclear plant in Florida, where lid leaks were identified several weeks ago.

For full coverage of Davis-Besse, go to www.cleveland.com/davisbesse/

To reach these Plain Dealer reporters:

jmangels@plaind.com, 216-999-4842

jfunk@plaind.com, 216-999-4138