1. Headline
  1. Headline
Image: Nuclear power plant
Mike Segar  /  Reuters
Where's the U.S. nuclear power plant with the greatest risk of being damaged by an earthquake? Not on the Pacific coastline. It's on the Hudson River.
Investigative reporter Bill Dedman of msnbc.com
By Bill Dedman Investigative reporter
msnbc.com
updated 3/17/2011 3:13:18 AM ET 2011-03-17T07:13:18

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 of an earthquake strong enough to cause damage to the reactor's core, which could expose the public to radiation. No tsunami required. That's 10 times more likely than you winning $10,000 by buying a single 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 an earthquake causing core damage 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.

  1. Stories from
    1. Chris Pratt: My Premature Son 'Restored My Faith in God'
    2. Behind the Real-Life Family Tragedy That Inspired David Duchovny’s New Movie
    3. Relive PEOPLE's Twitter Chat with The Giver Star Odeya Rush
    4. Harley Pasternak: Losing Weight Quickly Can Actually Be Healthy
    5. Murdered Teen Reportedly Texted Boyfriend, 'I Think I'm Being Kidnapped'

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 nation's 104 commercial nuclear reactors is shown at the bottom of this article, listing the NRC estimate of risk of an earthquake causing core damage.

The chance of an earthquake causing core damage 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.

Update:Gov. Cuomo orders review of N.Y. reactor after report on quake data.

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 an earthquake that would cause core damage 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.

Update: The NRC on March 19 released answers to frequently asked questions about risks to U.S. nuclear plants from earthquake or tsunami. PDF file.

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.

U.S. Geological Survey
Based on 2008 data, a map of earthquake damage risk in the United States. The highest risk areas are purple, red and orange.

U.S. Geological Survey
Based on 1982 data, a map of earthquake damage risk in the continental United States. The highest risk areas are red, yellow and purple.

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 an earthquake causing core damage, 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.

3. Limerick 1 and 2, Limerick, Pa.: 1 in 18,868. Old estimate: 1 in 45,455. Increase in risk: 141 percent.

4. Sequoyah 1 and 2, Soddy-Daisy, Tenn.: 1 in 19,608. Old estimate: 1 in 102,041. Increase in risk: 420 percent.

5. Beaver Valley 1, Shippingport, Pa.: 1 in 20,833. Old estimate: 1 in 76,923. Increase in risk: 269 percent.

6. Saint Lucie 1 and 2, Jensen Beach, Fla.: 1 in 21,739. Old estimate: N/A.

7. North Anna 1 and 2, Louisa, Va.: 1 in 22,727. Old estimate: 1 in 31,250. Increase in risk: 38 percent.

8. Oconee 1, 2 and 3, Seneca, S.C.: 1 in 23,256. Old estimate: 1 in 100,000. Increase in risk: 330 percent.

9. Diablo Canyon 1 and 2, Avila Beach, Calif.: 1 in 23,810. Old estimate: N/A.

10. Three Mile Island, Middletown, Pa.: 1 in 25,000. Old estimate: 1 in 45,455. Increase in risk: 82 percent.

(This short list of the top 10 sites, or plants, groups together reactors at the same site if they have the same risk rating, such as Sequoyah 1 and 2. The full list of 104 separate reactors is below at the bottom of the text.)

U.S. Geological Survey
Based on 1969 data, a map of earthquake damage risk in the continental United States. The highest risk areas are red and yellow.

A rising risk
Northeast of Chattanooga, Tenn., the Tennessee Valley Authority's Sequoyah 1 and 2 nuclear plants had been thought to have a risk of core damage from an earthquake happening once every 102,041 years. The new estimate is once every 19,608 years.

That kind of change was typical. Out of 104 reactors, the risk estimate declined at only eight. (There were 19 for which no older estimate was available for comparison.)

The increase in risk is so rapid that an NRC research task force in September sent two recommendations to NRC management:

First, it is time to move the issue over from the research staff to the regulatory staff, moving from study to action.

Second, start figuring out whether some nuclear power plants need a "backfit," or additional construction to protect them from earthquakes.

Another indication of how fast the risk estimates rose: The median, or middle value out of all 104 reactors, a measure of the risk at the typical plant, is now at a 1 in 74,176 chance each year of core damage from a quake. In the old estimate, it was 1 in 263,158. In other words, the estimated risk, though still low by NRC standards, has more than tripled.

What happens next?
This NRC process began in 2005 when its staff recommended taking a look at updated seismic hazards. It was late 2008 before NRC staff started working with a contractor, Electric Power Research Institute, on the design of a study. Overall, it took five years and three months from the staff recommendation until the seismic task force submitted its report in August 2010.

One problem is a lack of data about the nuclear reactors themselves. The NRC task force said the agency has detailed data on what it calls plant fragility — the probability that the expected earthquake would damage the reactor's core — for only one-third of the nation's nuclear plants. That's because only the plants that had been thought to be in areas of higher seismic risk had done detailed studies. For the rest, the scientists had to estimate from other information submitted by plant operators.

Now the NRC is playing catch-up.

An NRC spokesman, Scott Burnell, said Tuesday that the NRC is preparing a letter to send to certain nuclear plants, asking them for the more detailed data on equipment, soil conditions and seismic preparedness. Then the plants and NRC staff will have an opportunity to analyze that data.

That process could stretch into 2012, Burnell said. Then the NRC will have to decide, he said, "where the ability to respond to seismic events can be improved."

In the middle of that process, perhaps late this year, a new round of geologic data will come out. That will be folded into new calculations.

Industry is "addressing that issue"
The nuclear power industry is watching this process. A document distributed to the public by the industry's Nuclear Energy Institute on Sunday, after the Japanese plant emergency began, referred to this NRC study and the possibility of changes, saying, "The industry is working with the NRC to develop a methodology for addressing that issue."

The industry statement did not mention that the study increased the estimates of earthquake risk for nearly every nuclear power plant in the U.S.

(One of the leading nuclear power companies, General Electric, which designed the reactors at Fukushima, is a part owner of NBCUniversal, which co-owns msnbc.com through a joint venture with Microsoft.)

Good odds or bad?
How much risk is too much? Is a roller coaster safe only if no one ever dies? If one passenger dies every 100 years? Every year?

When the NRC saw that the new earthquake maps had pushed the level of risk into the range between 1 in 100,000 and the more likely 1 in 10,000, that change was enough to study the issue further, the task force said in its report. But because the risks didn't go beyond 1 in 10,000, "there was no immediate concern regarding adequate protection." The new estimates put Indian Point right at that boundary, and a few others in reach.

By comparison, the chance of winning the grand prize in the next Powerball lottery: 1 in 195,249,054.

Ranking of nuclear reactors by earthquake damage risks
Here are the 104 nuclear power reactors in the United States, ranked by the NRC's estimate of the risk each year that an earthquake would cause damage to the reactor's core, possibly releasing radiation.

Notes: Data come from the NRC's study of August 2010 on reactors in the central and eastern states, supplemented by data provided by the NRC to msnbc.com in March 2011. The table shows the risks calculated separately from 1989 and 2008 earthquake data from the U.S. Geological Survey. Ranks and changes in risk are calculated by msnbc.com. For the reactors in the western states, and a few others, the 1989 estimate was not provided to msnbc.com, so no change is calculated. The information in this list is also available in an Excel spreadsheet file. (See resources, below.)

Rank. Reactor, nearby city, state: Chance each year of core damage from an earthquake, showing NRC estimates based on 2008 USGS data. Old estimate from 1989 data. Change in risk.
1. Indian Point 3, Buchanan, N.Y.: 1 in 10,000 chance each year. Old estimate: 1 in 17,241. Change in risk: 72 percent.

2. Pilgrim 1, Plymouth, Mass.: 1 in 14,493 chance each year. Old estimate: 1 in 125,000. Change in risk: 763 percent.

3. Limerick 1, Limerick, Pa.: 1 in 18,868 chance each year. Old estimate: 1 in 45,455. Change in risk: 141 percent.

3. Limerick 2, Limerick, Pa.: 1 in 18,868 chance each year. Old estimate: 1 in 45,455. Change in risk: 141 percent.

5. Sequoyah 1, Soddy-Daisy, Tenn.: 1 in 19,608 chance each year. Old estimate: 1 in 102,041. Change in risk: 420 percent.

5. Sequoyah 2, Soddy-Daisy, Tenn.: 1 in 19,608 chance each year. Old estimate: 1 in 102,041. Change in risk: 420 percent.

7. Beaver Valley 1, Shippingport, Pa.: 1 in 20,833 chance each year. Old estimate: 1 in 76,923. Change in risk: 269 percent.

8. Saint Lucie 1, Jensen Beach, Fla.: 1 in 21,739 chance each year. Old estimate: N/A. Change in risk: N/A.

8. Saint Lucie 2, Jensen Beach, Fla.: 1 in 21,739 chance each year. Old estimate: N/A. Change in risk: N/A.

10. North Anna 1, Louisa, Va.: 1 in 22,727 chance each year. Old estimate: 1 in 31,250. Change in risk: 38 percent.

10. North Anna 2, Louisa, Va.: 1 in 22,727 chance each year. Old estimate: 1 in 31,250. Change in risk: 38 percent.

12. Oconee 1, Seneca, S.C.: 1 in 23,256 chance each year. Old estimate: 1 in 100,000. Change in risk: 330 percent.

12. Oconee 2, Seneca, S.C.: 1 in 23,256 chance each year. Old estimate: 1 in 100,000. Change in risk: 330 percent.

12. Oconee 3, Seneca, S.C.: 1 in 23,256 chance each year. Old estimate: 1 in 100,000. Change in risk: 330 percent.

15. Diablo Canyon 1, Avila Beach, Calif.: 1 in 23,810 chance each year. Old estimate: N/A. Change in risk: N/A.

15. Diablo Canyon 2, Avila Beach, Calif.: 1 in 23,810 chance each year. Old estimate: N/A. Change in risk: N/A.

17. Three Mile Island 1, Middletown, Pa.: 1 in 25,000 chance each year. Old estimate: 1 in 45,455. Change in risk: 82 percent.

18. Palo Verde 1, Wintersburg, Ariz.: 1 in 26,316 chance each year. Old estimate: N/A. Change in risk: N/A.

18. Palo Verde 2, Wintersburg, Ariz.: 1 in 26,316 chance each year. Old estimate: N/A. Change in risk: N/A.

18. Palo Verde 3, Wintersburg, Ariz.: 1 in 26,316 chance each year. Old estimate: N/A. Change in risk: N/A.

18. Summer, Jenkensville, S.C.: 1 in 26,316 chance each year. Old estimate: 1 in 138,889. Change in risk: 428 percent.

22. Catawba 1, York, S.C.: 1 in 27,027 chance each year. Old estimate: 1 in 33,333. Change in risk: 23 percent.

22. Catawba 2, York, S.C.: 1 in 27,027 chance each year. Old estimate: 1 in 33,333. Change in risk: 23 percent.

24. Watts Bar 1, Spring City, Tenn.: 1 in 27,778 chance each year. Old estimate: 1 in 178,571. Change in risk: 543 percent.

25. Indian Point 2, Buchanan, N.Y.: 1 in 30,303 chance each year. Old estimate: 1 in 71,429. Change in risk: 136 percent.

26. Duane Arnold, Palo, Iowa: 1 in 31,250 chance each year. Old estimate: N/A. Change in risk: N/A.

27. McGuire 1, Huntersville, N.C.: 1 in 32,258 chance each year. Old estimate: 1 in 35,714. Change in risk: 11 percent.

27. McGuire 2, Huntersville, N.C.: 1 in 32,258 chance each year. Old estimate: 1 in 35,714. Change in risk: 11 percent.

29. Farley 1, Columbia, Ala.: 1 in 35,714 chance each year. Old estimate: 1 in 263,158. Change in risk: 637 percent.

29. Farley 2, Columbia, Ala.: 1 in 35,714 chance each year. Old estimate: 1 in 263,158. Change in risk: 637 percent.

31. Quad Cities 1, Cordova, Ill.: 1 in 37,037 chance each year. Old estimate: 1 in 71,429. Change in risk: 93 percent.

31. Quad Cities 2, Cordova, Ill.: 1 in 37,037 chance each year. Old estimate: 1 in 71,429. Change in risk: 93 percent.

33. River Bend 1, St. Francisville, La.: 1 in 40,000 chance each year. Old estimate: 1 in 370,370. Change in risk: 826 percent.

34. Peach Bottom 2, Delta, Pa.: 1 in 41,667 chance each year. Old estimate: 1 in 120,482. Change in risk: 189 percent.

34. Peach Bottom 3, Delta, Pa.: 1 in 41,667 chance each year. Old estimate: 1 in 120,482. Change in risk: 189 percent.

36. Crystal River 3, Crystal River, Fla.: 1 in 45,455 chance each year. Old estimate: 1 in 192,308. Change in risk: 323 percent.

36. Seabrook 1, Seabrook, N.H.: 1 in 45,455 chance each year. Old estimate: 1 in 114,943. Change in risk: 153 percent.

36. Beaver Valley 2, Shippingport, Pa.: 1 in 45,455 chance each year. Old estimate: 1 in 188,679. Change in risk: 315 percent.

39. Perry 1, Perry, Ohio: 1 in 47,619 chance each year. Old estimate: 1 in 1,176,471. Change in risk: 2371 percent.

39. Columbia 1, Richland, Wash.: 1 in 47,619 chance each year. Old estimate: N/A. Change in risk: N/A.

41. Waterford 3, Killona, La.: 1 in 50,000 chance each year. Old estimate: 1 in 833,333. Change in risk: 1567 percent.

42. Dresden 2, Morris, Ill.: 1 in 52,632 chance each year. Old estimate: 1 in 434,783. Change in risk: 726 percent.

42. Dresden 3, Morris, Ill.: 1 in 52,632 chance each year. Old estimate: 1 in 434,783. Change in risk: 726 percent.

42. Monticello, Monticello, Minn.: 1 in 52,632 chance each year. Old estimate: 1 in 38,462. Change in risk: -27 percent.

45. Wolf Creek 1, Burlington, Kansas: 1 in 55,556 chance each year. Old estimate: 1 in 400,000. Change in risk: 620 percent.

46. San Onofre 2, San Clemente, Calif.: 1 in 58,824 chance each year. Old estimate: N/A. Change in risk: N/A.

46. San Onofre 3, San Clemente, Calif.: 1 in 58,824 chance each year. Old estimate: N/A. Change in risk: N/A.

48. Millstone 3, Waterford, Conn.: 1 in 66,667 chance each year. Old estimate: 1 in 100,000. Change in risk: 50 percent.

48. Brunswick 1, Southport, N.C.: 1 in 66,667 chance each year. Old estimate: 1 in 263,158. Change in risk: 295 percent.

48. Brunswick 2, Southport, N.C.: 1 in 66,667 chance each year. Old estimate: 1 in 263,158. Change in risk: 295 percent.

48. Robinson 2, Hartsville, S.C.: 1 in 66,667 chance each year. Old estimate: 1 in 370,370. Change in risk: 456 percent.

52. Oyster Creek, Forked River, N.J.: 1 in 71,429 chance each year. Old estimate: 1 in 126,582. Change in risk: 77 percent.

53. Fort Calhoun, Fort Calhoun, Neb.: 1 in 76,923 chance each year. Old estimate: N/A. Change in risk: N/A.

53. Ginna, Ontario, N.Y.: 1 in 76,923 chance each year. Old estimate: 1 in 238,095. Change in risk: 210 percent.

53. Susquehanna 1, Salem Township, Pa.: 1 in 76,923 chance each year. Old estimate: 1 in 416,667. Change in risk: 442 percent.

53. Susquehanna 2, Salem Township, Pa.: 1 in 76,923 chance each year. Old estimate: 1 in 416,667. Change in risk: 442 percent.

57. Calvert Cliffs 2, Lusby, Md.: 1 in 83,333 chance each year. Old estimate: 1 in 116,279. Change in risk: 40 percent.

57. D.C. Cook 1, Bridgman, Mich.: 1 in 83,333 chance each year. Old estimate: N/A. Change in risk: N/A.

57. D.C. Cook 2, Bridgman, Mich.: 1 in 83,333 chance each year. Old estimate: N/A. Change in risk: N/A.

57. Grand Gulf 1, Port Gibson, Miss.: 1 in 83,333 chance each year. Old estimate: 1 in 106,383. Change in risk: 28 percent.

57. Kewaunee, Kewaunee, Wis.: 1 in 83,333 chance each year. Old estimate: 1 in 71,429. Change in risk: -14 percent.

62. Millstone 2, Waterford, Conn.: 1 in 90,909 chance each year. Old estimate: 1 in 156,250. Change in risk: 72 percent.

62. Salem 1, Hancocks Bridge, N.J.: 1 in 90,909 chance each year. Old estimate: 1 in 172,414. Change in risk: 90 percent.

62. Salem 2, Hancocks Bridge, N.J.: 1 in 90,909 chance each year. Old estimate: 1 in 172,414. Change in risk: 90 percent.

62. Point Beach 1, Two Rivers, Wis.: 1 in 90,909 chance each year. Old estimate: 1 in 76,923. Change in risk: -15 percent.

62. Point Beach 2, Two Rivers, Wis.: 1 in 90,909 chance each year. Old estimate: 1 in 76,923. Change in risk: -15 percent.

67. Turkey Point 3, Homestead, Fla.: 1 in 100,000 chance each year. Old estimate: N/A. Change in risk: N/A.

67. Turkey Point 4, Homestead, Fla.: 1 in 100,000 chance each year. Old estimate: N/A. Change in risk: N/A.

67. Calvert Cliffs 1, Lusby, Md.: 1 in 100,000 chance each year. Old estimate: 1 in 142,857. Change in risk: 43 percent.

70. Vermont Yankee, Vernon, Vt.: 1 in 123,457 chance each year. Old estimate: 1 in 434,783. Change in risk: 252 percent.

71. Braidwood 1, Braceville, Ill.: 1 in 136,986 chance each year. Old estimate: 1 in 1,785,714. Change in risk: 1204 percent.

71. Braidwood 2, Braceville, Ill.: 1 in 136,986 chance each year. Old estimate: 1 in 1,785,714. Change in risk: 1204 percent.

73. Vogtle 1, Waynesboro, Ga.: 1 in 140,845 chance each year. Old estimate: 1 in 384,615. Change in risk: 173 percent.

73. Vogtle 2, Waynesboro, Ga.: 1 in 140,845 chance each year. Old estimate: 1 in 384,615. Change in risk: 173 percent.

75. Cooper, Brownville, Neb.: 1 in 142,857 chance each year. Old estimate: N/A. Change in risk: N/A.

76. Davis-Besse, Oak Harbor, Ohio: 1 in 149,254 chance each year. Old estimate: 1 in 625,000. Change in risk: 319 percent.

77. Palisades, Covert, Mich.: 1 in 156,250 chance each year. Old estimate: N/A. Change in risk: N/A.

78. South Texas 1, Bay City, Texas: 1 in 158,730 chance each year. Old estimate: 1 in 1,298,701. Change in risk: 718 percent.

78. South Texas 2, Bay City, Texas: 1 in 158,730 chance each year. Old estimate: 1 in 1,298,701. Change in risk: 718 percent.

80. FitzPatrick, Scriba, N.Y.: 1 in 163,934 chance each year. Old estimate: 1 in 833,333. Change in risk: 408 percent.

81. Byron 1, Byron, Ill.: 1 in 172,414 chance each year. Old estimate: 1 in 1,470,588. Change in risk: 753 percent.

81. Byron 2, Byron, Ill.: 1 in 172,414 chance each year. Old estimate: 1 in 1,470,588. Change in risk: 753 percent.

83. Surry 1, Surry, Va.: 1 in 175,439 chance each year. Old estimate: 1 in 123,457. Change in risk: -30 percent.

83. Surry 2, Surry, Va.: 1 in 175,439 chance each year. Old estimate: 1 in 123,457. Change in risk: -30 percent.

85. Nine Mile Point 2, Scriba, N.Y.: 1 in 178,571 chance each year. Old estimate: 1 in 1,000,000. Change in risk: 460 percent.

86. Browns Ferry 2, Athens, Ala.: 1 in 185,185 chance each year. Old estimate: 1 in 625,000. Change in risk: 238 percent.

86. Browns Ferry 3, Athens, Ala.: 1 in 185,185 chance each year. Old estimate: 1 in 625,000. Change in risk: 238 percent.

88. Nine Mile Point 1, Scriba, N.Y.: 1 in 238,095 chance each year. Old estimate: 1 in 1,724,138. Change in risk: 624 percent.

88. Fermi 2, Monroe, Mich.: 1 in 238,095 chance each year. Old estimate: 1 in 625,000. Change in risk: 163 percent.

90. Arkansas Nuclear 1, London, Ark.: 1 in 243,902 chance each year. Old estimate: 1 in 1,063,830. Change in risk: 336 percent.

90. Arkansas Nuclear 2, London, Ark.: 1 in 243,902 chance each year. Old estimate: 1 in 1,063,830. Change in risk: 336 percent.

92. Comanche Peak 1, Glen Rose, Texas: 1 in 250,000 chance each year. Old estimate: 1 in 833,333. Change in risk: 233 percent.

92. Comanche Peak 2, Glen Rose, Texas: 1 in 250,000 chance each year. Old estimate: 1 in 833,333. Change in risk: 233 percent.

94. Browns Ferry 1, Athens, Ala.: 1 in 270,270 chance each year. Old estimate: 1 in 1,000,000. Change in risk: 270 percent.

95. Prairie Island 1, Welch, Minn.: 1 in 333,333 chance each year. Old estimate: 1 in 714,286. Change in risk: 114 percent.

95. Prairie Island 2, Welch, Minn.: 1 in 333,333 chance each year. Old estimate: 1 in 714,286. Change in risk: 114 percent.

97. La Salle 1, Marseilles, Ill.: 1 in 357,143 chance each year. Old estimate: 1 in 1,851,852. Change in risk: 419 percent.

97. La Salle 2, Marseilles, Ill.: 1 in 357,143 chance each year. Old estimate: 1 in 1,851,852. Change in risk: 419 percent.

97. Hope Creek 1, Hancocks Bridge, N.J.: 1 in 357,143 chance each year. Old estimate: 1 in 909,091. Change in risk: 155 percent.

100. Clinton, Clinton, Ill.: 1 in 400,000 chance each year. Old estimate: 1 in 370,370. Change in risk: -7 percent.

101. Shearon Harris 1, New Hill, N.C.: 1 in 434,783 chance each year. Old estimate: 1 in 277,778. Change in risk: -36 percent.

102. Hatch 1, Baxley, Ga.: 1 in 454,545 chance each year. Old estimate: 1 in 1,351,351. Change in risk: 197 percent.

102. Hatch 2, Baxley, Ga.: 1 in 454,545 chance each year. Old estimate: 1 in 1,351,351. Change in risk: 197 percent.

104. Callaway, Fulton, Mo.: 1 in 500,000 chance each year. Old estimate: N/A. Change in risk: N/A.

A few words about the data (Where's Richter?)
The NRC's risk estimates are not based on the usual layman's language of the magnitude scale (the old Richter scale or its replacement, the moment magnitude scale). Magnitude shows the earthquake's energy released. That is a measure of power.

How much radiation is dangerous?

But a nuclear plant may be close to the epicenter of a quake, or far from it. And some types of seismic waves are more jarring than others.

Instead, these risk estimates consider how violently the ground will shake at the nuclear plant, considered a better indication of how much damage it will cause. That shaking can be affected by the depth, distance from the epicenter, and the frequencies of waves that the quake emits. The shaking is expressed in a unit called peak ground acceleration, in terms of the acceleration caused by the Earth's gravity. This is a measure of intensity.

Often these two ways of measuring earthquakes are roughly in synch, but sometimes not. For example:

  • The 2010 Haiti earthquake, magnitude 7.0, rated only "severe" on the intensity scale, the third rung from the top, with peak ground acceleration of 0.5 times the Earth's gravity.
  • The 2010 Chile earthquake, with a much higher magnitude of 8.8, was one step higher in terms of intensity, "violent," with peak ground acceleration of 0.65 times gravity.
  • The 2010 Christchurch or Canterbury earthquake in New Zealand, similar to Haiti at magnitude 7.1, was at the top of the intensity scale, "extreme," with a peak ground acceleration of 1.26 times gravity.

Besides the peak acceleration, the NRC made other estimates for each nuclear plant, based on different types of earthquakes.

From all these estimates, the NRC calculated a worst case, which it called the "weakest link." Msnbc.com ranked the plants by that worst case, which is the same number the NRC staff highlights in its report, and the only number it provided for the reactors in the western states.

Resources
These links open in a new window.

NRC answers to frequently asked questions on earthquake and tsunami risk. PDF file.

Earthquake history of each state, from the USGS.

  1. More investigative reports
    1. Only four of 20 subpoenaed in Christie bridge investigation comply by deadline
    2. Hoffman withdrew $1,200 from ATM the night before he was found dead: sources
    3. Christie campaign seeks OK to raise funds for bridge investigation legal costs
    4. Feds ask NJ lawmakers not to interfere with criminal probe in bridge scandal
    5. Latest allegation in New Jersey bridge scandal piles on political woe for Chris Christie

A USGS brochure describing the changes in the 2008 seismic hazard maps. PDF file.

The NRC report with new earthquake risk estimates, "Generic Issue 199 (GI-199), Implications of Updated Probabilistic Seismic Hazard Estimates in Central and Eastern United States on Existing Plants, Safety/Risk Assessment," August 2010. PDF file. Note: Data for individual reactors are in appendix D.

An NRC fact sheet from November 2010, "Seismic Issues for Existing Nuclear Power Plants."

The NRC database of active nuclear reactors in the U.S. Each reactor name links to technical and safety documents.

Industry response to questions about the situation in Japan. PDF file.

A scientific paper describing the New Madrid earthquake, and what can be learned by melding modern science with writings from long ago.

A brochure with a table comparing values for magnitude and peak ground acceleration.

The ranking of 104 nuclear plants by risk, by msnbc.com from NRC data, in an Excel spreadsheet file.

© 2013 msnbc.com Reprints

Submit:

Send your ideas to NBC News Investigations

What should we investigate? Do you know of a story that we should pursue at NBC News? We're about investigative reporting on topics that matter: corruption, conflicts of interest, broken systems, abuses by institutions and individuals with power, whether that's government, nonprofits, or the press itself.

Tell us your idea...

 

 

Images must be .gif, .jpg/jpeg or .png formats. Combined file size limit: 40MB.Each file size should be larger than 1KB.

Image file Caption *

Image file Caption *

Image file Caption *

(3000 character limit)

How to reach you...

 

 

By clicking the Send button, I acknowledge and accept the following:

  • Submissions are reviewed by NBC News staff, and published or broadcast at their discretion.
  • NBC News may contact me via e-mail or phone if my content is used or with questions about my submission.
  • I agree to the terms of the NBC News Privacy Policyand Terms & Conditions.

Video: Chernobyl, Three Mile Island revisited

  1. Transcript of: Chernobyl, Three Mile Island revisited

    MATT LAUER, co-host: But we want to begin this half-hour with very serious news, and we're talking about the nuclear crisis in Japan . People living within 12 miles of the Fukushima plant have been evacuated. Officials warned anyone within 19 miles to simply stay indoors. As Savannah mentioned earlier, there are 104 nuclear power plants in the United States , some very close to major population

    centers: the Indian Point plant, about 35 miles north of New York City , home to more than eight million people; approximately 35 miles outside of Philadelphia , Pennsylvania , with a population of a million and a half sits the Limerick Generating Station ; and the Waterford Steam Electric Station is just 30 miles outside of New Orleans , which as we know is an area vulnerable to hurricanes. So how does a nuclear disaster impact the people and environment surrounding a plant? This morning we're live at the sites of both Three Mile Island in Pennsylvania and Chernobyl , beginning with NBC 's Jeff Rossen at Three Mile Island . Jeff , good morning to you.

    JEFF ROSSEN reporting: Hey, Matt , good morning to you. This plant is still very much active. You can see one of the reactors still going this morning with two of the cooling stacks sending steam into the air. We just talked to one of the officials from here. They supply power here at Three Mile Island to 800,000 homes here in the Northeast , most of them in Pennsylvania . You know, back in 1979 when the partial core meltdown happened here at Three Mile Island , they were ill-prepared. They're the first admit that. No real evacuation plan, a shoddy emergency plan . But this morning everything has changed inside while things out here are basically the same.

    Ms. JOAN ESPENSHADE (Lives Behind Three Mile Island): We didn't know. It was scary...

    Mr. KENNETH ESPENSHADE: Yeah.

    Ms. ESPENSHADE: ...and we knew the sirens had gone off, and somebody said something happened at the nuclear power plant . And...

    ROSSEN: Chaos.

    Ms. ESPENSHADE: Chaos.

    ROSSEN: It was March 1979 , a partial core meltdown at Three Mile Island that shut the plant down and sent radioactive gas into the air; all of it just a stone's throw from Joan and Kenneth 's house.

    Ms. ESPENSHADE: We had a five-year-old son we had to worry about. We had to worry about his safety. And yeah, our concern was to get him out of the area.

    Unidentified Reporter: Good morning, everyone. Some radioactive steam still leaking this morning from a damaged nuclear power plant in Pennsylvania .

    ROSSEN: It was a combination of mechanical failure and human error, to this day the most serious nuclear power accident in American history .

    Offscreen Voice: You're not finding anything, are you, Brian ?

    BRIAN: Not a damn thing.

    ROSSEN: Believe it or not , no one died, and studies show there have been no long-term health issues. But there was fallout. Americans were scared, and for the nuclear power industry the timing couldn't have been worse.

    ROSSEN: The movie " The China Syndrome " was released just days before the accident, showing a Hollywood version of a nuclear meltdown , and set the tone for the real-world emergency playing out in Pennsylvania .

    Ms. ESPENSHADE: The biggest concern was, can I get back?

    ROSSEN: A presidential commission ordered sweeping changes at Three Mile Island and the government agency that oversees it. Today, 32 years later, officials here say it's safe.

    Mr. RALPH DESANTIS (Three Mile Island Spokesman): We want people to know that we have redundant and numerous safety systems at Three Mile Island .

    ROSSEN: We're in your backyard right now.

    Ms. ESPENSHADE: Right.

    ROSSEN: And you are literally in the shadow of this nuclear power plant .

    Ms. ESPENSHADE: Correct.

    ROSSEN: Make you nervous?

    Ms. ESPENSHADE: No, no. I can't say that it does. I mean, we had -- we have families and friends that all worked on the island and, you know, it was part of our lives.

    ROSSEN: In fact, at the local cafe we found many of the same people who experienced the accident as kids still live here as adults.

    Unidentified Woman #1: We don't think about it day to day . But now that this is in the news, it makes you wonder what really did happen then and what could happen in the future.

    ROSSEN: You think about this.

    Unidentified Woman #2: Yeah. We have iodine pills in our home in case something happens.

    Mr. ESPENSHADE: This is probably the safest nuclear plant in the country because of the focus that was on it before.

    Ms. ESPENSHADE: That's right .

    Mr. ESPENSHADE: If I have to live around one, this is the one I'll live around.

    ROSSEN: Just to give you an idea what they're in for now in Japan , here at Three Mile Island it took them 12 years and $1 billion nearly to clean up the mess here. And of course, that was without all the damage and the death and the carnage from a quake and a tsunami, Savannah .

    SAVANNAH GUTHRIE, co-host: Jeff Rossen , experts already saying what we're seeing in Japan is worse than Three Mile Island .

    SAVANNAH GUTHRIE, co-host: Well, next month marks the 25th anniversary of Chernobyl , the world's worst nuclear accident . NBC 's Michelle Kosinski is there. Michelle , good morning.

    MICHELLE KOSINSKI reporting: Hi , Savannah . Chernobyl was the worst nuclear accident in history 25 years ago next month. And to this day there is this 20-mile radius exclusion zone around it. You need special clearance to get back there, which they haven't granted us yet this time around. And there's still a higher level of radiation in places here than is normal, but it's diminished enough that Ukraine is now ready to offer Chernobyl as an extreme tourism destination. Overgrown, eerie, much of it touched only by time since then. April 1986 , Russia was slow to admit that during safety tests one of the Chernobyl nuclear reactors overloaded, exploded and melted down. The enormous burst of radiation killed dozens of emergency workers , spread across Europe , and scientists say in the years that followed spiked the number of thyroid cancer cases in the region.

    Mr. ROBERT ALVAREZ (Institute for Policy Studies): Currently an area about half the size of New Jersey is uninhabitable and may be that way for hundreds of years.

    KOSINSKI: It remains a silent specter: the empty schools; hulking, abandoned Soviet buildings; the amusement park that never amused anyone, set to open days after the disaster; and the aging sarcophagus, the structure built over the corpse of the nuclear reactor to contain the radioactivity still inside. Yet birds nest around it, flowers bloom.

    Unidentified Woman: Right now the radiation levels are -- they're on the high side.

    KOSINSKI: Not silent here are the dosimeters that identify radioactive hot spots. All of this video was captured by our NBC cameras six years ago.

    Unidentified Man: Looks like you could still get in and go for a ride.

    KOSINSKI: Even then a few tourists ventured in, and some hardy residents moved back to farm. But officials here have determined that today the radiation level is low enough to bring people through on tours to show them the sort of nuclear nowhere that Japan is desperate to prevent. At least there, unlike Chernobyl , huge protective barriers surround the reactors.

    Mr. ALVAREZ: We are all keeping our fingers crossed and hoping and praying that if things take an even greater turn to the worst that these barriers will serve to prevent large releases from occurring.

    KOSINSKI: Here, what was a paragon of what humans can do, split the atom to cleanly power our inventions, has returned to absolute basics. The US Nuclear Regulatory Commission says in this region now there is no overall increase in cancer or disease that can be attributed to Chernobyl , although there could still be some 4,000 radiation-related deaths in the future among the hundreds of thousands of people exposed back then. Here lies the lonely evidence, poisoned by people, reclaimed by the earth. And in addition to the increased tourism now here -- we saw tourists going in today -- Ukraine also wants to build an even bigger containment dome over that old reactor. It'll take years to build and will cost around a billion

    dollars. Savannah: All right, Michelle Kosinski in Chernobyl this morning, thank you.

    GUTHRIE:

Interactive: Japan before and after the disaster

These aerial photos show locations in Japan before and after the 9.0-magnitude earthquake and tsunami that struck March 11. Use the slider below the images to reveal the changes in the landscape.

Explainer: The 10 deadliest earthquakes in recorded history

  • A look at the worst earthquakes in recorded history, in loss of human life. (The March 11, 2011, earthquake and tsumani that affected eastern Japan is not included because the fatalities caused, about 15,000, are fewer than those resulting from the temblors listed below.) Sources: United States Geological Survey, Encyclopedia Britannica

  • 1: Shensi, China, Jan. 23, 1556

    Magnitude about 8, about 830,000 deaths.

    This earthquake occurred in the Shaanxi province (formerly Shensi), China, about 50 miles east-northeast of Xi'an, the capital of Shaanxi. More than 830,000 people are estimated to have been killed. Damage extended as far away as about 270 miles northeast of the epicenter, with reports as far as Liuyang in Hunan, more than 500 miles away. Geological effects reported with this earthquake included ground fissures, uplift, subsidence, liquefaction and landslides. Most towns in the damage area reported city walls collapsed, most to all houses collapsed and many of the towns reported ground fissures with water gushing out.

  • 2: Tangshan, China, July 27, 1976

    Chinese Earthquake
    Keystone  /  Getty Images
    1976: Workers start rebuilding work following earthquake damage in the Chinese city of Tangshan, 100 miles east of Pekin, with a wrecked train carriage behind them. (Photo by Keystone/Getty Images)
    Magnitude 7.5. Official casualty figure is 255,000 deaths. Estimated death toll as high as 655,000.

    Damage extended as far as Beijing. This is probably the greatest death toll from an earthquake in the last four centuries, and the second greatest in recorded history.

  • 3: Aleppo, Syria, Aug. 9, 1138

    Magnitude not known, about 230,000 deaths.

    Contemporary accounts said the walls of Syria’s second-largest city crumbled and rocks cascaded into the streets. Aleppo’s citadel collapsed, killing hundreds of residents. Although Aleppo was the largest community affected by the earthquake, it likely did not suffer the worst of the damage. European Crusaders had constructed a citadel at nearby Harim, which was leveled by the quake. A Muslim fort at Al-Atarib was destroyed as well, and several smaller towns and manned forts were reduced to rubble. The quake was said to have been felt as far away as Damascus, about 220 miles to the south. The Aleppo earthquake was the first of several occurring between 1138 and 1139 that devastated areas in northern Syria and western Turkey.

  • 4: Sumatra, Indonesia, Dec. 26, 2004

    Aerial images show the extent of the devastation in Meulaboh
    Getty Images  /  Getty Images
    MEULABOH, INDONESIA - DECEMBER 29: In this handout photo taken from a print via the Indonesian Air Force, the scene of devastation in Meulaboh, the town closest to the Sunday's earthquake epicentre, is pictured from the air on December 29, 2004, Meulaboh, Aceh Province, Sumatra, Indonesia. The western coastal town in Aceh Province, only 60 kilometres north-east of the epicentre, has been the hardest hit by sunday's underwater earthquake in the Indian Ocean. Officials expected to find at least 10,000 killed which would amount to a quarter of Meulaboh's population. Three-quarters of Sumatra's western coast was destroyed and some towns were totally wiped out after the tsunamis that followed the earthquake. (Photo by Indonesian Air Force via Getty Images)

    Magnitude 9.1, 227,898 deaths.

    This was the third largest earthquake in the world since 1900 and the largest since the 1964 Prince William Sound, Alaska temblor. In total, 227,898 people were killed or were missing and presumed dead and about 1.7 million people were displaced by the earthquake and subsequent tsunami in 14 countries in South Asia and East Africa. (In January 2005, the death toll was 286,000. In April 2005, Indonesia reduced its estimate for the number missing by over 50,000.)

  • 5: Haiti, Jan 12, 2010

    Haitians walk through collapsed building
    Jean-philippe Ksiazek  /  AFP/Getty Images
    Haitians walk through collapsed buildings near the iron market in Port-au-Prince on January 31, 2010. Quake-hit Haiti will need at least a decade of painstaking reconstruction, aid chiefs and donor nations warned, as homeless, scarred survivors struggled today to rebuild their lives. AFP PHOTO / JEAN-PHILIPPE KSIAZEK (Photo credit should read JEAN-PHILIPPE KSIAZEK/AFP/Getty Images)

    Magnitude 7.0. According to official estimates, 222,570 people killed.

    According to official estimates, 300,000 were also injured, 1.3 million displaced, 97,294 houses destroyed and 188,383 damaged in the Port-au-Prince area and in much of southern Haiti. This includes at least 4 people killed by a local tsunami in the Petit Paradis area near Leogane. Tsunami waves were also reported at Jacmel, Les Cayes, Petit Goave, Leogane, Luly and Anse a Galets.

  • 6: Damghan, Iran, Dec. 22, 856

    Magnitude not known, about 200,000 deaths.

    This earthquake struck a 200-mile stretch of northeast Iran, with the epicenter directly below the city of Demghan, which was at that point the capital city. Most of the city was destroyed as well as the neighboring areas. Approximately 200,000 people were killed.

  • 7: Haiyuan, Ningxia , China, Dec. 16, 1920

    7.8 magnitude, about 200,000 deaths.

    This earthquake brought total destruction to the Lijunbu-Haiyuan-Ganyanchi area. Over 73,000 people were killed in Haiyuan County. A landslide buried the village of Sujiahe in Xiji County. More than 30,000 people were killed in Guyuan County. Nearly all the houses collapsed in the cities of Longde and Huining. About 125 miles of surface faulting was seen from Lijunbu through Ganyanchi to Jingtai. There were large numbers of landslides and ground cracks throughout the epicentral area. Some rivers were dammed, others changed course.

  • 8: Ardabil, Iran, March. 23, 893

    Magnitude not known, about 150,000 deaths

    The memories of the massive Damghan earthquake (see above) had barely faded when only 37 years later, Iran was again hit by a huge earthquake. This time it cost 150,000 lives and destroyed the largest city in the northwestern section of the country. The area was again hit by a fatal earthquake in 1997.

  • 9: Kanto, Japan, Sept. 1, 1923

    Kanto Damage
    Hulton Archive  /  Getty Images
    1923: High-angle view of earthquake and fire damage on Hongokucho Street and the Kanda District, taken from the Yamaguchi Bank building after the Kanto earthquake, Tokyo, Japan. (Photo by Hulton Archive/Getty Images)
    7.9 magnitude, 142,800 deaths.

    This earthquake brought extreme destruction in the Tokyo-Yokohama area, both from the temblor and subsequent firestorms, which burned about 381,000 of the more than 694,000 houses that were partially or completely destroyed. Although often known as the Great Tokyo Earthquake (or the Great Tokyo Fire), the damage was most severe in Yokohama. Nearly 6 feet of permanent uplift was observed on the north shore of Sagami Bay and horizontal displacements of as much as 15 feet were measured on the Boso Peninsula.

  • 10: Ashgabat, Turkmenistan, Oct. 5, 1948

    7.3 magnitude, 110,000 deaths.

    This quake brought extreme damage in Ashgabat (Ashkhabad) and nearby villages, where almost all the brick buildings collapsed, concrete structures were heavily damaged and freight trains were derailed. Damage and casualties also occurred in the Darreh Gaz area in neighboring Iran. Surface rupture was observed both northwest and southeast of Ashgabat. Many sources list the casualty total at 10,000, but a news release from the newly independent government on Dec. 9, 1988, advised that the correct death toll was 110,000. (Turkmenistan had been part of the Soviet Union, which tended to downplay the death tolls from man-made and natural disasters.)

Discuss:

Discussion comments

,

More on TODAY.com

  1. Ann and Steve Toon/Solent News

    Two abandoned baby hedgehogs get some TLC after a prickly start

    7/30/2014 6:42:41 PM +00:00 2014-07-30T18:42:41
  1. Michael Dwyer / AP

    Five cases when buyer's remorse will cost you big

    7/30/2014 9:03:12 PM +00:00 2014-07-30T21:03:12
  1. Courtesy Graves family

    Death-defying: Mom battled cancer while ‘feisty’ baby waited for a new heart

    7/30/2014 2:52:11 PM +00:00 2014-07-30T14:52:11
  1. Strike on Gaza shopping area kills at least a dozen, wounds 150

    An Israeli airstrike hit a crowded Gaza shopping area on Wednesday, killing at least 16 people and wounding more than 150, just hours after Israeli tank shells slammed into a U.N. school, Gaza health officials said.

    7/30/2014 5:38:37 PM +00:00 2014-07-30T17:38:37
  1. Twitter.com/SarahDrewGreys

    'Grey's Anatomy' star Sarah Drew reveals her baby bump

    7/30/2014 5:07:52 PM +00:00 2014-07-30T17:07:52