Image via WikipediaBy Bill Dedman Investigative reporter
msnbc.com msnbc.com
What are the odds that a nuclear emergency like the one at Fukushima Dai-ichi could happen in the central or eastern United States? They'd have to be astronomical, right? As a pro-nuclear commenter on msnbc.com put it this weekend, "There's a power plant just like these in Omaha. If it gets hit by a tsunami...."It turns out that the U.S. Nuclear Regulatory Commission has calculated the odds of an earthquake causing catastrophic failure to a nuclear plant here. Each year, at the typical nuclear reactor in the U.S., there's a 1 in 74,176 chance that the core could be damaged by an earthquake, exposing the public to radiation. No tsunami required. That's 10 times more likely than you winning $10,000 by buying a ticket in the Powerball multistate lottery, where the chance is 1 in 723,145.
And it turns out that the nuclear reactor in the United States with the highest risk of core damage from a quake is not the Diablo Canyon Power Plant, with its twin reactors tucked between the California coastline and the San Andreas Fault.
It's not the San Onofre Nuclear Generating Station, a four-hour drive down the Pacific coast at San Clemente, surrounded by fault lines on land and under the ocean.
It's not on the Pacific Coast at all. It's on the Hudson River.
One in 10,000
The reactor with the highest risk rating is 24 miles north of New York City, in the village of Buchanan, N.Y., at the Indian Point Energy Center. There, on the east bank of the Hudson, Indian Point nuclear reactor No. 3 has the highest risk of earthquake damage in the country, according to new NRC risk estimates provided to msnbc.com.
A ranking of the 104 nuclear reactors is shown at the bottom of this article, listing the NRC estimate of risk of catastrophic failure caused by earthquake.
The chance of a core damage from a quake at Indian Point 3 is estimated at 1 in 10,000 each year. Under NRC guidelines, that's right on the verge of requiring "immediate concern regarding adequate protection" of the public. The two reactors at Indian Point generate up to one-third of the electricity for New York City. The second reactor, Indian Point 2, doesn't rate as risky, with 1 chance in 30,303 each year.
The plant with the second highest risk? It's in Massachusetts. Third? Pennsylvania. Then Tennessee, Pennsylvania again, Florida, Virginia and South Carolina. Only then does California's Diablo Canyon appear on the list, followed by Pennsylvania's Three Mile Island.
The odds take into consideration two main factors: the chance of a serious quake, and the strength of design of the plant.
Nuclear power plants built in the areas usually thought of as earthquake zones, such as the California coastline, have a surprisingly low risk of damage from those earthquakes. Why? They built anticipating a major quake.
Other plants in the East, South and Midwest, where the design standards may have been lower because the earthquake risk was thought to be minimal, now find themselves at the top of the NRC's danger list.
The chance of serious damage from a quake ranges from Indian Point's 1 chance in 10,000 each year, a relatively higher risk, to the Callaway nuclear plant in Fulton, Mo., where the NRC set the lowest risk, 1 chance in 500,000 each year.
Playing the odds
The NRC, the federal agency responsible for nuclear power safety, says the odds are in the public's favor. "Operating nuclear power plants are safe," the NRC said when it reported the new risk estimates.
Every plant is designed with a margin of safety beyond the strongest earthquake anticipated in that area, the NRC says.
But the NRC also says the margin of safety has been reduced.
In the 35 years since Indian Point 3 got its license to operate in 1976, the same era when most of today's U.S. nuclear reactors were built, geologists have learned a lot about the dangers of earthquakes in the eastern and central U.S.
No one alive now has memories of the South Carolina quakes of 1886, which toppled 14,000 chimneys in Charleston and were felt in 30 states. Or the New Madrid quakes of 1811-1812 in Missouri and Arkansas — the big one made the Mississippi River run backward for a time.
But the geologists and seismologists remember, learning their history from rocks, and steadily raising their estimates of the risk of severe quakes. New faults are found, and new computer models change predictions for how the ground shakes. The latest estimates are drawn from the 2008 maps of the U.S. Geological Survey.
Of special note, the USGS said, was an allowance for waves of large earthquakes in the New Madrid fault area roughly centered on the Missouri Bootheel, as well as inclusion of offshore faults near Charleston, S.C., and new data from the mountains of East Tennessee. With each new map, the areas of negligible risks have receded.
Based on those new maps, the NRC published in August 2010 new estimates of the earthquake risk at nuclear power reactors in the eastern and central states. Besides the proximity, severity and frequency of earthquakes, the new estimates take into account the design standards used at each plant, along with the type of rock or soil it's built on. This week, the NRC provided additional data to msnbc.com for the relatively few reactors in the Western states, allowing a ranking to be made of all 104 reactors with the latest data.
The top 10
Here are the 10 nuclear power sites with the highest risk of suffering core damage from an earthquake, showing their NRC risk estimates based on 2008 and 1989 geological data.
1. Indian Point 3, Buchanan, N.Y.: 1 in 10,000 chance each year. Old estimate: 1 in 17,241. Increase in risk: 72 percent.
2. Pilgrim 1, Plymouth, Mass.: 1 in 14,493. Old estimate: 1 in 125,000. Increase in risk: 763 percent.
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