AEP Sees Reactor Vessel Head Replacements For Cook Plant
Thursday January 16, 10:01 am ET
NEW YORK (Dow Jones)--American Electric Power Co. is pursuing the replacement of the reactor vessel heads at its Bridgman, Mich., Cook plant in the wake of tighter inspection schedules imposed on the industry after massive corrosion found at an Ohio reactor.
According to plant spokesman Bill Schalk, the Columbus, Ohio-based company has recently come to the conclusion that the added cost of more frequent inspections, which can extended outages, outweighs the cost of replacing the heavy reactor lids.
"Although we haven't found any reportable damage," said Schalk, "the requirement of increased inspections of the reactor head justifies the cost of replacing it."
Schalk said the company had yet to sign a contract for the replacement parts.
"We're still finalizing the cost, schedule and final approval within AEP," he said.
Operators conducted in-depth inspections of the Westinghouse-designed vessel heads at both plants during scheduled outages last year.
Unit 2 was inspected and refueled in 40 days last January, while unit 1 was down for 36 days in May.
The outages were the shortest on record but Schalk said conducting inspections cost the company in additional contractor workers and a few extra days off line.
The announcement coincides with this week's unveiling of a series of regulatory reforms in the wake of massive corrosion found at FirstEnergy Corp.'s (FE) Davis-Besse reactor near Toledo, Ohio.
On Tuesday, senior Nuclear Regulatory Commission officials announced that henceforth, the agency would conduct more rigorous inspections, demand more assurances that problems have been fixed and act more quickly to respond to problems as they appear.
The changes, some of which are already under way, stem from a highly critical internal report of the NRC's failure to react to signs of trouble at the Davis- Besse reactor, where a large rust hole was found on the reactor lid last March.
Since then, 68 other pressurized water reactors, which are prone to stress corrosion cracking on parts made with a weak nickel alloy, have had to report on the condition of their vessel heads. The NRC has also put in place a schedule for in-depth inspections based on susceptibility to corrosion.
The most vulnerable reactors are now required to do non-visual inspections, using various electrical and ultrasonic techniques, during every refueling outage.
"Doing the inspections did add some days to the outages," said Schalk, but anticipating the need for repairs can cost money too. "In our most recent inspections we had personnel standing by," he said, "so there is an expense in the potential repair."
About a dozen vessel head replacements have been announced in the past two years and more are expected as reactors age.
"The key element is that pressurized-water stress corrosion cracking is a time-dependent degradation mechanism, which means if you don't have the cracking now there is no guarantee you won't have the cracking later," said Alex Marion, the Nuclear Energy Institute's director of engineering. "The likelihood increases over time, so you will see more and more utilities replace their vessel head over time," he said.
While most companies are reluctant to specify a dollar amount for the work, the cost of a vessel head replacement varies between $15 million and $50 million, depending on the complexity of the job and the cost of replacement power during the two to three months the plant is off line.
In addition to Davis-Besse, one other replacement is under way at Dominion Resources Inc.'s (D) North Anna unit 2 reactor in Virginia.
Duke Energy Corp. (NYSE:DUK - News) is next, with a vessel head to be installed this spring at its Oconee unit 3 reactor in South Carolina.
-By Jennifer Morrow; Dow Jones Newswires; 201-938-4377; jennifer.morrow@ dowjones.com |
