Concerns, assurances over Calvert Cliffs and Peach Bottom

Like many Americans, Linda Billings has been following news of the unfolding crisis in earthquake-rocked Japan, where a crippled nuclear power plant teeters on the brink of a disastrous meltdown.

But the 55-year-old Street resident is paying perhaps a bit more attention than most. Her home in northern Harford County is less than 10 miles from a similarly designed nuclear plant just across the border in Pennsylvania.

"I've not worried about it, but perhaps I should," she said late last week. "It would certainly be nice to know the U.S. plants are safer."

Industry spokesmen say the 104 nuclear power reactors operating in the United States — including two in Southern Maryland and the two just north of the Harford line in Delta, Pa. — are "the safest in the world." Each has redundant safety systems and highly trained workers ready to respond to all manner of emergencies, the spokesmen say.

"We don't have any reason to believe that the U.S. plants aren't safe," said Nuclear Regulatory Commission spokesman Neil Sheehan. "The Japanese reactors were confronted with a very unlikely set of circumstances — the fifth-largest recorded earthquake followed by a tremendous tsunami. … This is really beyond what anybody could have conceived of."

But the calamity that's unfolded in Japan has prompted the Obama administration to call for a thorough review of the safety of U.S. nuclear plants. The five-member NRC is to meet Monday in Rockville to review how the Fukushima incident might highlight the need to make further safety improvements in this country.

More than 77,000 Marylanders live within 10 miles of a pair of nuclear power plants, the Peach Bottom facility in Delta and Calvert Cliffs. But many more live within 50 miles — the distance at which U.S. officials were urging Americans in Japan to get from the damaged Fukushima plant. Peach Bottom is about 45 miles from Baltimore; Calvert Cliffs is 74 miles away.

Earthquakes are generally mild in this region, and tsunamis are unheard of. Industry experts point out that plants are designed to withstand the worst recorded tremors in a given location.

At Calvert Cliffs, built on the shore of the Chesapeake Bay, even the backup diesel generators that might be needed in an emergency are placed inside quake-resistant structures beyond the reach of the highest flooding anyone expects from a hurricane in these parts — about 16 feet, according to Mark C. Sullivan, spokesman for Constellation Energy Nuclear Group, which owns the plant.

And Peach Bottom on the Susquehanna River, says David Tillman, spokesman for Chicago-based Exelon Corp., is prepared for flooding, droughts and even dam breaks that might affect their supply of water to keep its twin reactors from overheating.

"We're prepared for high water, we're prepared for low water — we're prepared for no water," Tillman said.

But nuclear energy critics said power plants in this region could get into similarly serious trouble if some other unanticipated event occurred that was then compounded by failures of key safety equipment and worker mistakes. And others point to incidents last year at Peach Bottom and Calvert Cliffs, which they said demonstrate troubling lapses in attention to safety.

"It doesn't need to be an earthquake and tsunami in Pennsylvania or Maryland to initiate it," said Paul Gunter of Beyond Nuclear, an anti-nuclear group in Takoma Park. "It could be a different set of initiators, starting with a tree limb on a transmission line that shuts down the power," he added. If backup diesel generators fail to work for any reason, then U.S. plants also would have to rely on emergency batteries to maintain necessary safety systems for just four to eight hours.

Critics also note that there have been longstanding safety concerns voiced about the design of the reactors in Japan — and that there are 23 of the same type in this country, including two at Peach Bottom.

Mark 1: pros, cons

Most U.S. reactors, including those at Calvert Cliffs, are pressurized water reactors, in which the reactor core is sealed inside a thick containment chamber of steel and concrete. But Peach Bottom and the Fukushima plant have "Mark 1" boiling-water reactors, made by General Electric Co., in which the same water used to cool the reactor converts to steam to drive the turbines.

In 1972, a safety official with the Atomic Energy Commission, the government precursor to the Nuclear Regulatory Commission, warned that the Mark 1 was susceptible to hydrogen gas building up inside, exploding and breaching the containment, releasing dangerous radiation. Another NRC official voiced similar concerns in the 1980s.

"Peach Bottom Units 2 and 3 are dead ringers for the Fukushima reactor design that's now hanging on a catastrophe," said Gunter.

But plant operators have made a number of modifications to strengthen the reactors since safety concerns were raised about them decades ago, said David Helwig, an energy industry consultant who's worked on Mark 1 reactors.

"That got identified years ago, and everybody took care of that," said Helwig. In fact, he argued that the boiling-water reactors' design is easier to shut down safely in an emergency because its design is simpler than the more common pressurized water reactors.

Another design similarity that worries some, though, is that each Mark 1 plant stores its spent nuclear fuel in a pool of water above the reactor. A rooftop spent fuel pool at the Fukushima plant evidently lost some or even all of its water, allowing the fuel rods to overheat and give off highly radioactive gases and particles. Workers there have struggled to get cooling water back into the pool and the reactors.

Some say the rooftop spent fuel pools are inherently risky, with less shielding them from harm.

"Spent fuel pools have basically one system to cool them and very flimsy, nonreliable structures around them in case fuel is released," said David Lochbaum, nuclear safety director for the Union of Concerned Scientists, a watchdog group. A nuclear engineer who's worked at U.S. plants, Lochbaum called the setup "a recipe for disaster," and said U.S. plants store much more used fuel in their pools than was being kept at the Japanese plant.

NRC spokesman Sheehan said plant owners have taken steps to protect the pools better from fire and explosions since 2001, when the terrorist attacks prompted another wave of safety and security evaluations at all U.S. plants.

Critics say they're also concerned that government regulators may not be keeping a tight enough rein on safety and security lapses among plant workers and managers.

The Union of Concerned Scientists released a report last week pointing to what it called 14 "near-misses" last year, in which it said plant operators and government regulators ignored or played down warning signs before the event.

One was an unplanned shutdown at Calvert Cliffs in February 2010, when rain and melting snow leaked through the roof of the reactor building, causing an electrical short that triggered a shutdown of both reactors.

"Workers had noted numerous leaks across many, many months prior to this event, but management always deferred repairs," said Lochbaum.

Compounding the problem, one of the backup diesel generators that's supposed to run safety equipment at Calvert Cliffs in emergencies started up, but promptly shut down as well.

The shutdown drew a special team of NRC inspectors to Lusby to investigate. According to the union's report, they found that leaks had been reported at the plant as far back as 2002. About six months before the shutdown, the report said, water had been found leaking through the roof onto an electrical panel. Workers covered the panel with a plastic sheet and drained the water into a bucket.

"The plant owner discussed corrective actions but never took them," the report says.

Stopping the water leak

Glenn Dentel, the NRC's branch chief overseeing Constellation Energy's three nuclear plants, said the plant management did make some roof repairs in the years before the shutdown. But regulators decided after their investigation that the company had not been aggressive enough in dealing with the chronic problem.

The NRC also wrote up the company for the diesel generator failure, after tracing the breakdown to a faulty electric relay that the manufacturer had recommended be replaced years before.

The NRC official said the roof leaks at Calvert Cliffs were considered a low-to-moderate safety issue, while the diesel generator failure was of very low significance — because the plant still had four other generators that worked and only needs two to keep the reactors from overheating.

The scientists' union also raised concerns about Peach Bottom, saying workers there didn't shut down a reactor promptly — as safety rules required — after discovering a problem with some of the control rods needed to manage the nuclear fission. Lochbaum faults government inspectors as well, saying they let the plant bend the rules to avoid a costly unplanned outage.

But Paul Krohn, NRC branch chief for the plant, said no rules were broken because workers were able to fix enough of the problem rods before a shutdown would have been required.

Some think the U.S. nuclear industry and government regulators pay more attention to safety now because of the scare Americans had 31 years ago with the partial meltdown of a reactor at Three Mile Island near Harrisburg, Pa., 84 miles from Baltimore. Though no one was killed or injured, it brought sweeping changes in emergency planning, worker training and tighter government oversight.

"I think that nuclear power plants in this country are at a different level of safety, broadly speaking, than nuclear power plants in Japan — though they started out at the same level," said Jonathan M. Links, a medical physicist and director of the Center for Public Health Preparedness at the Johns Hopkins Bloomberg School of Public Health.

Trina Tobin, for one, says she isn't fretting about Calvert Cliffs, even though she can see the plant on the far shore of the Chesapeake Bay from her home on Taylor's Island in Dorchester County.

Tobin, 54, said it did bother her to be so close to a nuclear plant when she and her husband first moved to the island 20 years ago.

"But after a couple years, you just get over it and you don't worry about it anymore, she added. She was issued potassium iodide pills, a remedy for mild radiation poisoning, as a precaution against a possible leak from the plant. But she says she doesn't know where the pills are now.

"I grew up down south, and I went through hurricanes," she said. "You've just got to live and don't worry about it."

tim.wheeler@baltsun.com

An earlier version had an incorrect name for energy industry consultant David Helwig. The Sun regrets the error.

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