- The Washington Times - Monday, May 13, 2002

RICHMOND Small cracks in the reactors at Virginia's two nuclear power plants are prompting concern among some industry watchdogs that necessary safety precautions are not being taken to prevent serious problems.
Twenty-one cracks have been found in the control-rod nozzles and tubes at the two plants North Anna and Surry over the last year, according to the Nuclear Regulatory Commission (NRC). Three of the cracks were leaking minute amounts of boric acid, which is used as a coolant in reactors.
Of the 21 cracks, nine have been repaired including those that were leaking but the others have not, said Rick Zuercher, spokesman for the operator of the plants, Dominion Virginia Power. Mr. Zuercher said the remaining fissures are so hairline thin, they "do not pose any threat."
But some industry critics, including the Nuclear Information and Resource Service (NIRS) in Washington, say the cracks may not hold up until the next inspection period, when the reactors shut down for refueling.
That happens every 18 months in Virginia.
"The chief concern is we don't know how quickly cracks can grow during one operating cycle to result in failure of the reactor," said Paul Gunter, director of the Reactor Watchdog Project at NIRS. The nuclear industry "is operating in the dark here and will continue to do so."
The heightened concern follows the discovery of a hole at the Davis Besse power plant in Ohio two months ago and severe cracks in other reactors nationwide over the past year.
The 6-inch hole in the steel dome of the Besse reactor was caused by the accumulation of boric acid that had leaked from tiny fissures similar to the ones found in the Virginia plants.
The discovery was made when the U.S. government ordered inspections of all power plants after 23 cracks were discovered in the nuclear reactors at the Oconee plant in Greensville, S.C., in the spring of 2001. Those cracks have subsequently been fixed.
So far, no one else is reporting the kind of corrosion found at the Ohio plant. But the two Virginia plants have been placed on an NRC "close-watch" list with 12 other plants that have reported cracks in the past year, industry officials said.
Mr. Gunter fears what happened at the Besse plant could happen in Virginia, or at any of the 12 plants on the list.
"Not only did they miss the cracks [in Ohio], they missed the eating away of the vessel head," he said. "It's always a problem leaving defective, cracked material in service."
Mr. Zuercher, however, said Dominion has taken the necessary steps to meet NRC safety standards, as well as American Society of Mechanical Engineers regulations under which all nuclear power plants operate.
"There is very hard data about how well this material holds up," Mr. Zuercher said. "The NRC would never let a plant operate if it were dangerous."
Roger Hannah, spokesman for the NRC's second division in Atlanta, agreed that the precautions taken are acceptable.
"If there were any strong possibilities that these sorts of things could lead to serious safety issues, they certainly would be addressed immediately," he said.
The areas where officials are most concerned about cracking are the tubes that carry the boric acid into the reactors and, specifically, the welded nozzles where the nozzles meet the roof of the reactors. The tubes are made of alloy 600, a durable metal said to be resistant to corrosion.
The cracks that remain in the Virginia plants, measuring 2 millimeters deep at the most, are in the tubes, not the nozzles, Mr. Zuercher said. Cracks in the nozzles are generally considered more dangerous. The boric acid accumulation at the Besse reactor was caused by leakage in the nozzles.
The minute amounts of boric acid found on the outside of the tubes at the Virginia plants were also caused by leakage in the nozzles. The accumulation was only discovered after officials conducted a close-up inspection of the reactors last fall following reports of the cracks at Oconee.
As a result of the findings, Dominion officials decided to make the close-up inspections a regular, 18-month occurrence, Mr. Zuercher said. There is also now talk of replacing the reactor heads themselves, which range in age from 22 to 30 years old.
"We made the determination [the cracks] will be fine to support 18 months of operation," he said. "If we didn't feel comfortable going 18 months, we would fix it; we wouldn't mess around."

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