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Archive for Thursday, February 8, 1996

WOLF CREEK TO UNDERGO CRITICAL TESTS

February 8, 1996

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Power companies and federal regulators will be closely monitoring the results of tests about to begin at the only nuclear power plant in Kansas.

The Wolf Creek nuclear power plant in Burlington is about to undergo a series of controversial tests to determine if crucial components are corroding and cracking as they have in at least nine similar plants around the nation.

While the plant's operators and the U.S. Nuclear Regulatory Commission say the planned tests are sufficient, critics say the tests are unreliable and miss cracks that could cause a catastrophic release of radiation comparable to the deadly 1986 Chernobyl accident.

Beyond safety concerns, the cracking, if found to be extensive, could create a financial dilemma for the plant's owners: repair the cracks at great expense or shut down the plant decades sooner than planned.

In 1992, such cracks forced the permanent shutdown of the Trojan nuclear plant in Rainier, Ore., because its operators didn't want to pay $200 million for repairs.

So the upcoming tests will be closely watched by Wolf Creek's owners and by the NRC, which is evaluating the reliability of its testing standards.

"It's very important," said Mona Grimsley, a spokeswoman for the Wolf Creek Nuclear Operating Corp., which manages the plant for its corporate owners. "These tests will give us a picture of our steam generator tubes, and they'll let us know if we need to do more inspections."

Extended shutdown

Wolf Creek, a $3 billion plant about 55 miles south of Topeka, opened in 1985 and is jointly owned by Kansas Gas & Electric Co., Kansas City Power & Light Co. and Kansas Electric Power Cooperative.

The plant was scheduled for a routine refueling shutdown in March.

However, it stopped generating electricity on Jan. 30 because of frigid temperatures and ice that disabled a pump that draws lake water for cooling systems.

Although the weather-related problems were solved quickly, plant operators decided to keep Wolf Creek closed and to start refueling a month earlier than planned. The plant's operators are unsure how long the plant will be shut down.

The refueling, which involves replacement of about a third of the plant's 193 uranium fuel assemblies, is only part of what goes on during a refueling shutdown.

Workers and NRC inspectors perform a barrage of safety tests and replace and clean numerous parts. This happens about once every 18 months.

"A refueling outage is like doing a major maintenance on your car after you've driven it for a long time," said Grimsley.

Among the most important tests will be scans of 22,504 finger-thick tubes within the plant's four steam generators, which produce the steam that turns the plant's generating turbines.

Litmus test for technique

While Wolf Creek will use the latest testing technology to examine a small sampling of its steam generator tubes, the initial exams of those tubes will be done with an older and less sensitive technique.

Critics say that means the tests may miss many serious cracks.

The inadequacy of the older technique was discovered last year at the Maine Yankee nuclear power plant near Wicasset, Maine. Tests there using the newer technique revealed extensive corrosion that was missed six months earlier by inspectors who relied on the old technique.

In response to that discovery, the NRC ordered the operators of Wolf Creek and the other 71 pressurized water reactors in the nation to submit data on their steam generator tubes and to justify why the plants should be allowed to continue to operate.

The NRC is still evaluating the data.

"We've gone out and asked for additional information from almost every plant," said Breck Henderson, an NRC spokesman in Arlington, Tex.

"Based on the review of the data so far, we have not seen any need for immediate action or any alarm, and we haven't identified any issues and haven't requested any major changes in testing," Henderson said. "Which is not to say we won't when we get all our information and finish our review of it. These things take awhile."

In tests during past refueling shutdowns, no steam generator tube cracks were found at Wolf Creek.

However, tests last year at Wolf Creek's sister facility, the Calloway nuclear power plant near Fulton, Mo., about 100 miles west of St. Louis, revealed cracks in 29 tubes, which were plugged to take them out of service.

The NRC has allowed at least five other plants in Alabama, Michigan, South Carolina and Illinois to operate despite evidence of corroded steam generators, according to Public Citizen, a Washington, D.C., watchdog group.

Safety concerns

NRC and Wolf Creek engineers believe the plant's steam generator tubes will hold up better than those in the Calloway plant because they were made of an improved, heat-treated alloy.

Critics, including Robert Pollard, a former NRC engineer, have urged the federal agency to order the shutdown of all power plants like Wolf Creek until the government can be sure the plants are safe.

"Detection technology has improved in the last two years, but what they're noting is that the better the technology, the more cracks they're finding," said Paul Gunter of the Nuclear Information and Resource Service, an anti-nuclear group in Washington, D.C.

"Even the NRC has identified that within the industry a steam generator tube accident is inevitable," Gunter said. "The inevitability of that accident is a function of ongoing cracking and the inadequacy of detection technology.

"From our standpoint, public safety is what is paramount. The steam generator tubes are a weak link. This is the hole in the dike for that massive containment structure. Steam generator tubes vent directly outside."

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