Article published January 22, 2003
2 more nuke plants show coolant leaks
By TOM HENRY
BLADE STAFF WRITER
WASHINGTON - Two more nuclear plants have been found to have coolant leaks that led to reactor-head corrosion.
Neither plant - Sequoyah 2 in Tennessee nor Comanche Peak 1 in Texas - has a rust problem that rivals Davis-Besse's. But their cases could make the Nuclear Regulatory Commission's job of tightening standards tougher, because they further dispel the notion that minor boric acid leaks can be tolerated, an agency official said yesterday.
"That's been the ongoing assumption. We weren't concerned about the small leaks," conceded the NRC's Bill Beckner, who recently wrote an information notice for the industry to take nothing for granted and be wary of even the tiniest leaks. He said the NRC is "clearly more focused" on the issue now.
Boric acid is an additive in reactor coolant. Officials have said that for years they thought that seeping droplets would vaporize upon contact with a 600-degree steel reactor lid or, at worst, crystallize into powdery substances once the plants shut down.
The Davis-Besse case proved them wrong: Acid nearly burned through one part of that plant's reactor head, resulting in a chilling brush with a major nuclear accident.
Richard Wilkins, FirstEnergy spokesman, said the utility knew there was seepage but, in hindsight, did not act as promptly as it should have because it assumed the problem was nothing more than minor flange leaks.
Sequoyah 2's reactor-head corrosion, discovered Dec. 26, was no more than a third of a centimeter deep - a fraction of the six-inch-deep corrosion at Davis-Besse. Comanche Peak 1's reactor-head corrosion was too small to measure. Two pounds of boric acid crystal were recovered from its steel head, but that pales in comparison to the 900 pounds removed from Davis-Besse's reactor head, officials said.
David Lochbaum, a Union of Concerned Scientists nuclear safety engineer who has followed industry trends for years, said many utilities have managed leaks by cleaning off crystallization as it occurred. "That experience led the NRC to believe that dry powder was not a threat," he said.
FirstEnergy had minor corrosion on the reactor head of its Beaver Valley 1 nuclear plant near Pittsburgh years ago. That corrosion, traced to a 1989 seal leak, was less than an eighth of an inch deep, spokesman Todd Schneider said. A recent follow-up inspection on that head did not reveal any signs of a recurrence, he said.
In a related matter, Davis-Besse's timetable for refueling the plant's reactor, which was to begin Friday, has been pushed back at least a week. It is being delayed by administrative holdups with system reviews, Mr. Wilkins said. The plant has been idle since Feb. 16, 2002.
Permanent Link
|
|
 |
|
Search
advertisement
