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Risk From Spent Nuclear Reactor Fuel Is Greater in U.S. Than in Japan, Study Says

The report, from the Institute for Policy Studies, recommends that the United States transfer most of the nation’s spent nuclear fuel from pools filled with cooling water to dry sealed steel casks to limit the risk of an accident resulting from an earthquake, terrorism or other event.

“The largest concentrations of radioactivity on the planet will remain in storage at U.S. reactor sites for the indefinite future,” the report’s author, Robert Alvarez, a senior scholar at the institute, wrote. “In protecting America from nuclear catastrophe, safely securing the spent fuel by eliminating highly radioactive, crowded pools should be a public safety priority of the highest degree.”

At one plant that is a near twin of the Fukushima units, Vermont Yankee on the border of Massachusetts and Vermont, the spent fuel in a pool at the solitary reactor exceeds the inventory in all four of the damaged Fukushima reactors combined, the report notes.

After a March 11 earthquake and tsunami hit the Japanese plant, United States officials urged Americans to stay at least 50 miles away, citing the possibility of a major release of radioactive materials from the pool at Unit 4. The warning has reinvigorated debate about the safety of the far more crowded fuel pools at American nuclear plants.

Adding to concern, President Obama canceled a plan for a repository at Yucca Mountain in the Nevada desert last year, making it likely that the spent fuel will accumulate at the nation’s reactors for years to come.

The Nuclear Regulatory Commission maintains that both pool and cask storage are safe, although it plans to re-examine the pool issue in light of events at Fukushima.

Nearly all American reactors, especially the older ones, have far more spent fuel on hand than was anticipated when they were designed, Mr. Alvarez, a former senior adviser at the Department of Energy, wrote.

In general, the plants with the largest inventories are the older ones with multiple reactors. By Mr. Alvarez’s calculation, the largest amount of spent fuel is at the Millstone Point plant in Waterford, Conn., where two reactors are still operating and one is retired. The second-biggest is at the Palo Verde complex in Wintersburg, Ariz., the largest nuclear power plant in the United States, with three reactors.

Companies that run reactors are generally reluctant to say how much spent fuel they have on hand, citing security concerns. But Mr. Alvarez, drawing from the environmental impact statement for the proposed repository at Yucca Mountain, estimated the amount of radioactive material at all of the nation’s reactors.

In the 1960s, when most of the 104 reactors operating today were conceived, reactor manufacturers assumed that the fuel would be trucked away to factories for reprocessing to recover uranium. But reprocessing proved a commercial flop and was banned in the United States in the 1970s out of concerns that the plutonium could find its way into weapons worldwide.

Today roughly 75 percent of the nation’s spent nuclear fuel is stored in pools, the report said, citing data from the Nuclear Energy Institute. About 25 percent is stored in dry casks, or sealed steel containers within a concrete enclosure. The fuel is cooled by the natural flow of air around the steel container.

But spent fuel is transferred to dry casks only when reactor pools are nearly completely full. The report recommends instead that all spent nuclear fuel older than five years be stored in the casks. It estimated that the effort would take 10 years and cost $3.5 billion to $7 billion.

“With a price tag of as much as $7 billion, the cost of fixing America’s nuclear vulnerabilities may sound high, specially given the heated budget debate occurring in Washington,” Mr. Alvarez wrote. “But the price of doing too little is incalculable.”

The casks are not viewed as a replacement for a permanent disposal site, but as an interim solution that would last for decades.

The security of spent fuel pools also drew new attention after the attacks of Sept. 11, 2001, partly because one of the planes hijacked by terrorists flew down the Hudson River, over the Indian Point nuclear complex in Westchester County, before crashing into the World Trade Center in Manhattan.

Indian Point has pressurized water reactors with containment domes, but its spent fuel pools are outside the domes. The pools themselves are designed to withstand earthquakes and other challenges, but the surrounding buildings are not nearly as strong as those that house the reactors.

In a 2005 study ordered by Congress, the National Academy of Sciences also concluded that the pools were a credible target for terrorist attack and that consideration should be given to moving some fuel to dry casks.

Article source: http://feeds.nytimes.com/click.phdo?i=f2ad88bf482533c12613d94008dfa4e5

In Tour, U.S. Nuclear Plant Opens Doors to Make Case

The agency seemed to be seeking to project a balance of confidence and openness to improvements, a challenge now faced by the entire American nuclear industry as the nation watches the Japanese struggle to contain their crisis.

The containment buildings surrounding the three reactors at the Browns Ferry plant here, all of the Mark 1 variety made by General Electric, are almost identical to the ones at the Fukushima Daiichi Nuclear Power Station, which were wrecked by a tsunami on March 11. But the T.V.A. says that the devil is in the details, and that, in many small ways that could be crucial, Browns Ferry is better prepared for the unknown than Fukushima was.

In the decade since the Sept. 11 attacks, the Nuclear Regulatory Commission says, all American reactors have made preparations to limit damages from potential threats like airplanes piloted by terrorists. Some details have been released.

Yet it is clear that from fire hoses to batteries on wheels to components like a strobe light, the three reactors at Browns Ferry have preparations in place that operators say would help in a nightmare situation like Japan’s, a loss of electricity for running its pumps, valves and safety systems. While a tsunami is not an issue in northern Alabama, more than 300 miles from the sea, the loss of all power is always a threat. The plant sits on the banks of the Tennessee River, where floods can reasonably be anticipated, although plant officials say that water levels have never risen high enough to threaten the reactors.

Still, Browns Ferry is ready for “a one-in-a-million-year flood, or however many zeroes you want to go out,” said Preston D. Swafford, the T.V.A.’s chief nuclear officer, who led a group of reporters on a three-hour tour through the plant.

Inside the reactor building, near the entrance to the primary containment structure, are carefully marked spaces with two lime green carts about the size of hand trucks that a supermarket worker might use to roll cases of soda cans to the proper aisle. Each is loaded with batteries.

One cart could power the instruments that measure the water level in the reactor vessel, an ability that Japanese operators lost a few hours after the tsunami hit. Another could operate critical valves that failed early at Fukushima.

“They’re like a backup to the backup,” said Keith J. Polson, the T.V.A.’s vice president for the Browns Ferry site. “That’s what we think the Japanese didn’t have.”

In the best tradition of an industry whose terminology is ever more impenetrable to outsiders, the battery carts are known as E.D.M.G.’s, a label for hardware derived from the industry’s Extensive Damage Mitigation Guidelines, largely put into effect after the Sept. 11 attacks.

Deeper into the building, in an odd-shaped space in the basement between a corner of the square reactor building and the round containment shell is a steam-driven pump. This is something that the designer, General Electric, intended to be available to deliver up to 600 gallons per minute of cooling water into the reactor core even if the electrically driven pumps failed for want of power. An overheating reactor would be likely to have ample supplies of steam to run it.

That worked at Fukushima for a while but appears to have stopped functioning later; the Japanese plant’s operator, the Tokyo Electric Power Company, has not provided an explanation. Again, the T.V.A. suggests that it has backup tools that the Japanese utility, known as Tepco, probably lacked: a battery-powered strobe light stored in a nearby cabinet, and a valve that usually runs on electricity but also has a hand crank.

While the details of the Fukushima catastrophe may be months in reaching plant operators elsewhere, the T.V.A. hypothesizes that Tepco ran out of battery power to control the steam pump. But T.V.A. engineers say they could use the strobe light to determine how fast the pump’s shaft was turning, enabling workers to adjust its speed with a hand-cranked valve nearby.

Article source: http://feeds.nytimes.com/click.phdo?i=8c3e68dd3ad5b69e4288d83ba9e43637

Risk From Spent Nuclear Reactor Fuel Is Greater in U.S. Than in Japan, Study Says

In Tour, U.S. Nuclear Plant Opens Doors to Make Case

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