Archive for Sunday, June 4, 1995

AGING PARTS, CRACKS THREATEN WOLF CREEK

June 4, 1995

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— Federal regulators demand data on failing parts at most of the nation's nuclear power plants, including the Wolf Creek plant in Kansas.

The Wolf Creek nuclear plant here and 71 others like it around the nation have aging, straining parts that critics fear could burst, causing a catastrophic disaster comparable to the deadly 1986 Chernobyl accident.

On April 28, the U.S. Nuclear Regulatory Commission publicly acknowledged some of its own concerns with aging parts in nuclear power plants, ordering the operators of Wolf Creek -- the only nuclear power plant in Kansas -- and all other pressurized-water reactors in the nation to justify why they should be allowed to continue to operate.

The plants, which include most of the 108 commercial nuclear power plants in the United States, have until July 1 to submit their reports.

But nuclear power critics, including a former NRC engineer, say the unusual order didn't go far enough, and that the NRC is bending over backwards to allow plants that it can not be sure are safe to stay open.

The NRC counters that it has asked nuclear power plant operators to provide detailed information about their experience with aging parts so that the NRC can make a sound, reasoned decision about whether any plants need to be closed.

"The important thing is we're asking them all to take a very hard look at the situation," said Victor Dricks, an NRC spokesman in King of Prussia, Pa.

Brute power

The juice, all 25,000 volts of it, blazes through three innocuous metal pipes that jut out the otherwise blank, featureless north side of the Wolf Creek nuclear power plant, 55 miles south of Topeka.

The high voltage warnings posted around the pipes shrink in the shadow of a hodgepodge of steel and cables stoked with enough electricity to light a million homes.

But just inside the rectangular cavern that houses the plant's four turbines, the deafening roar of battleship gray machinery screams of power.

A small yellow sign warns: Hearing protection required in this area.

A public relations worker shouts into unprotected ears: "You know, a lot of people comment on how clean this place is."

Tidy as it may appear, it's been a long time since anybody promoted nuclear power as "clean." Buzz Carns of Lawrence, the 56-year-old ex-Navy captain who is now chief executive officer of the Wolf Creek Nuclear Operating Corp., is quick to point out that nuclear power plants do not emit the greenhouse gases that coal-burning power plants exhale. A growing body of evidence indicates those gases are affecting the global climate.

But nobody disputes that the deadly, cancer-causing radioactive waste produced in nuclear power plants is toxic for 10,000 years, that the nation still has no facility for disposing of such waste and that nobody knows just what to do with a nuclear power plant once it's shut down.

The shut-down question wasn't supposed to be a concern at Wolf Creek for decades. The $3 billion plant, jointly owned by Kansas Gas & Electric Co., Kansas City Power & Light Co. and Kansas Electric Power Cooperative, started generating power in 1985 with a typical 40-year operating license.

But now Carns and his nuclear power plant CEO counterparts across the nation face the prospect of closing their plants far sooner than expected, because repairs to crucial systems may prove too costly to justify to customers and shareholders.

"I think it's our obligation to run this plant as economically as possible and to prove its safety," Carns said.

Yet both goals present short-term and long-term challenges for nuclear power plants from coast to coast.

Tube trouble

Power plants like Wolf Creek generate electricity by turning turbines with steam.

A controlled splitting of uranium atoms -- similar to, but less explosive than, the fission in an atom bomb -- heats water that swirls around the plant's fuel core. But to keep that water contained, so that cancer-causing radiation doesn't escape into the atmosphere, an elaborate system of thousands of slender, water-filled tubes transfers the heat to nonradioactive water that flows around the tubes, which then becomes steam to turn the turbines.

In at least six plants similar to Wolf Creek, those tubes have developed tiny cracks, in some cases allowing radioactive water to leak through into the nonradioactive water.

And at least 14 nuclear power plant operating companies have filed lawsuits against Westinghouse Electric Corp. of Pittsburgh, alleging the company knew as early as 1964 that the material it used to build steam generator tubes, an alloy called Inconel 600, was flawed and degraded rapidly. None of the suits has gone to trial.

Westinghouse built the reactors and steam generators of 54 of the nation's nuclear power plants, including Wolf Creek.

Extensive cracks in steam generator tubes forced the permanent shutdown of the Trojan nuclear plant in Rainier, Ore., in 1992, because its operator, Portland General Electric Co., didn't want to pay $200 million for repairs. PGE has filed suit against Westinghouse.

In 1991, a steam generator tube split at Japan's Mihama nuclear plant, setting off the plant's emergency cooling systems to prevent core meltdown. The rupture, which officials blamed on faulty installation and not on cracks like those at Trojan, also forced a small release of radiation.

A tube failure in 1982 caused a small release of radioactive gas from the Ginna reactor near Rochester, N.Y.

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

Inadequate safeguard?

Nuclear power plants have emergency cooling systems designed to prevent the escape of radioactive material in the event a tube bursts.

But even Kenneth Rogers, a member of the Nuclear Regulatory Commission, acknowledged in 1988 that the simultaneous failure of more than one tube could be disastrous.

"Such failures could come about by having essentially uniform degradation of the tubes," Rogers said. "Degradation would decrease the safety margins so that, in essence, we have a loaded gun, an accident waiting to happen."

"You could lose the cooling inventory, uncover the core, start a fuel fire, a meltdown and breach of containment," said Paul Gunter of the Nuclear Information and Resource Service, an anti-nuclear group in Washington, D.C. "There's no difference between that and Chernobyl. It's different designs, but the consequences are the same with a catastrophic release of radiation into the atmosphere and the surrounding environment."

Wolf Creek has 22,504 tubes in its four steam generators. The tubes, three-quarters of an inch in diameter with walls about the thickness of a dime, are tested for cracks during routine shutdowns for refueling, and thus far no cracks have been detected. The next tests are planned during a refueling shutdown that starts in March 1996.

But tests earlier this year at the Maine Yankee nuclear power plant, near Wicasset, Maine, cast serious doubts on the reliability of the techniques engineers used in the past to check for steam generator tube cracks.

The most recent tests in Maine, using a newly developed and more sensitive technique, revealed steam generator tube cracking far more extensive than tests just six months earlier had revealed.

That result caused widespread uncertainty among nuclear engineers about the value of previous tests that showed less cracking, plunging the entire industry into a cloud of doubt.

"The problem is the NRC has been running tests which tell you nothing," said Bob Pollard, senior nuclear safety engineer for the Union of Concerned Scientists in Washington, D.C. In the 1970s he was an NRC engineer, responsible for the design and safety reviews of seven nuclear power plants.

The NRC says there's cause for concern, but not enough to shut down any plants, at least not yet.

"We don't believe that is either necessary or prudent at this time," the NRC's Dricks said. "What we have here is a new technology that allows us to identify a problem that previously would have passed inspection."

That's exactly why the NRC should be closing down nuclear power plants immediately, Pollard said. Instead, it has sent a letter asking for details of past tests -- tests that have been shown to be unreliable.

"The significance of the letter is the NRC believes that there is a strong possibility that similar cracks exist in other plants," Pollard said. "This means other plants may also have an extensive repair facing them. It is a major safety issue and a major economic issue. There are already some plants whose life will be determined solely by how long the steam generators last."

Costly cracks

Even if fears of catastrophic accidents prove unfounded, the operators of Wolf Creek expect that they, too, will eventually encounter cracks in their steam generator tubes.

"We think we may have a little more room before we see it, but I wouldn't be surprised if we see it," said Carns, the Wolf Creek CEO. "I would not bet that we would never have a crack. That would be a foolish bet. My commitment is we will not operate this plant if it is not safe."

Wolf Creek officials hope that any cracking they encounter will be less severe -- and less costly to repair -- than at Trojan or Yankee Maine because of heat-treated steam generator tubes that should be stronger.

Nationally, the costs of repairing or replacing decrepit steam generators could run into the billions -- $50 million to $200 million at each plant.

"The issues then become not only how long are these things going to last, but the effect on ratepayers and shareholders of the utilities which have operating nukes," said Bill Craven, a Topeka lobbyist for the Kansas Natural Resources Council, an environmental group that has long criticized nuclear power.

Economics are driving bad decisions right now, said Gunter, of the Nuclear Information and Resource Service.

"You have the industry, the regulator and the anti-nuclear movement all realizing that the plants are aging to the point where they seriously jeopardize public health and safety," Gunter said. "If you put public health and safety as the top priority, the licenses should be suspended until these questions are answered, and not operated in the face of all this uncertainty."

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