10/29/02

Washington- The Nuclear Regulatory Commission's five-member governing board is considering holding a rare fact-finding hearing of its own because of the unprecedented corrosion damage that has shuttered the Davis-Besse nuclear plant for eight months.

The commissioners are also considering changing the way they oversee commercial reactors, in the wake of the Davis-Besse debacle.

Top NRC officials revealed the developments yesterday during the first day of a three-day annual nuclear safety conference. The session was dominated by discussion of the problems at the Toledo-area plant, which continue to force federal regulators and the nuclear industry to rethink assumptions about the durability and maintenance of the massive lids atop the nation's nuclear reactors.

Davis-Besse "leads us down a path that says here's an area where we don't know as much as we thought," said Larry Mathews, chairman of a nuclear industry group studying why the nozzles in the lid are prone to cracking and leaking of the reactor's coolant.

"The whole world is learning from these issues."

Commissioners Jeffrey Merrifield and Nils Diaz, two of the NRC's five governors, said the commission will decide within the next several weeks whether to conduct an extraordinary meeting in which the agency, plant owner FirstEnergy Corp. and industry observers would review the factors that led to the pineapple-sized hole in the 6½-inch-thick steel lid. While the NRC staff continues to hold regular meetings on Davis-Besse, this would be the first time the commissioners have taken up the matter.

"I personally think it would be a good thing," Diaz said in an interview after addressing the safety conference attended by as many as 400 representatives of industry, government and universities.

Merrifield said the timing of such a hearing would depend on the progress of several agency investigations, including an inquiry into possible criminal wrongdoing by FirstEnergy in its successful campaign last fall to persuade the NRC to postpone a mandatory shutdown of Davis-Besse for a safety inspection. Investigators are trying to determine if FirstEnergy altered or withheld documents that would have shown the true condition of the lid.

Both commissioners and William Travers, the NRC's executive director for operations, defended the agency management's decision to allow the plant to keep operating, despite the staff's near certainty that Davis-Besse's lid was cracked and leaking.

"We made the appropriate judgment there," Travers said. "We'd all like to have more information. I'd like to have known that corrosion was occurring."

In the wake of a highly critical assessment by the agency of its oversight of Davis-Besse in the years leading up to the discovery this March of the rust hole, Travers said he has asked senior NRC managers to recommend changes in the way the agency operates.

Travers said he expects the group's report within weeks. He then could submit its findings to the commission for approval.

The NRC has not decided whether or when to allow Davis-Besse to resume making electricity. FirstEnergy is installing a new lid and making extensive repairs and improvements with the hope of restarting early next year.

Davis-Besse, along with other nuclear reactors where cracking and coolant leaks have recently been found, has spawned a major research effort to understand more about how cracks form, how fast they grow and how the leaking turns into a corrosive force.

At the time the rust hole was discovered at Davis-Besse, "there was a good deal of fundamental degradation rate data and corrosion rate data . . . that just simply did not exist," said William Cullen, senior materials engineer for the NRC.

The industry and the agency are each working on computer models that attempt to predict when and under what conditions cracks and corrosion will form and worsen. Those models disagree in some significant ways and are not yet ready to be used by the NRC for guidance.

The NRC's policy is that thorough, regular visual checks of the reactor lids are adequate to spot signs of leaking early enough to prevent major corrosion damage like that at Davis-Besse. However, recent inspections findings at several nuclear plants have shaken that confidence and are forcing the NRC and the industry to reconsider whether instrument-aided exams are warranted.

Regarding Davis-Besse, the NRC is employing two government labs to go beyond computer modeling. At Argonne, near Chicago, scientists are considering making a mockup of the rust hole to study corrosion growth. And at Oak Ridge, near Knoxville, Tenn., engineers are planning to test a replica of the thin stainless-steel liner, which was all that kept Davis-Besse's coolant from spewing out of the reactor. The lab will measure the pressure needed to burst the metal, which was bulging, cracked and thinner than expected.

FirstEnergy will pay for that research, said Cullen.

To reach these Plain Dealer reporters:

jmangels@plaind.com, 216-999-4842

jfunk@plaind.com, 216-999-4138

skoff@plaind.com, 216-999-4212