According to a 2010 survey of energy accidents, there have been at least 56 accidents near nuclear reactors in the United States (defined as incidents that either resulted in the loss of human life or more than US$50,000 of property damage). The most serious of these was the Three Mile Island accident in 1979. Davis-Besse Nuclear Power Plant has been the source of two of the top five most dangerous nuclear incidents in the United States since 1979.[1] Relatively few accidents have involved fatalities.[2]
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Globally, there have been at least 99 (civilian and military) recorded nuclear reactor accidents from 1952 to 2009 (defined as incidents that either resulted in the loss of human life or more than US$50,000 of property damage, the amount the US federal government uses to define major energy accidents that must be reported), totaling US$20.5 billion in property damages. Property damage costs include destruction of property, emergency response, environmental remediation, evacuation, lost product, fines, and court claims.[2] Because nuclear reactors are large and complex accidents onsite tend to be relatively expensive.[3]
At least 56 nuclear reactor accidents have occurred in the USA. Relatively few accidents have involved fatalities.[2] The most serious of these U.S. accidents was the Three Mile Island accident in 1979. According to the Nuclear Regulatory Commission, Davis-Besse has been the source of two of the top five most dangerous nuclear incidents in the United States since 1979.[1]
The Atomic Energy Act of 1954 encouraged private corporations in the United States to build nuclear reactors and a significant learning phase followed with many early partial core meltdowns and accidents at experimental reactors and research facilities.[4] This led to the introduction of the Price-Anderson Act in 1957, which was "an implicit admission that nuclear power provided risks that producers were unwilling to assume without federal backing".[4]
Nuclear reactor accidents continued into the 1960s with a small test reactor exploding at the Stationary Low-Power Reactor Number One in Idaho Falls in January 1961 resulting in three deaths which were the first fatalities in the history of U.S. nuclear reactor operations.[5] There was also a partial meltdown at the Enrico Fermi Nuclear Generating Station in Michigan in 1966.[4]
The large size of nuclear reactors ordered during the late 1960s raised new safety questions and created fears of a severe reactor accident that would send large quantities of radiation into the environment. In the early 1970s, a highly contentious debate over the performance of emergency core cooling systems in nuclear plants, designed to prevent a core meltdown that could lead to the "China syndrome", received coverage in the popular media and technical journals.[6][7]
In 1976, four nuclear engineers -- three from GE and one from the Nuclear Regulatory Commission—resigned, stating that nuclear power was not as safe as their superiors were claiming.[8][9] These men were engineers who had spent most of their working life building reactors,[10][11] and they testified to the Joint Committee on Atomic Energy that:
"the cumulative effect of all design defects and deficiencies in the design, construction and operations of nuclear power plants makes a nuclear power plant accident, in our opinion, a certain event. The only question is when, and where.[8]
On March 28, 1979, equipment failures and operator error contributed to loss of coolant and a partial core meltdown of Unit 2's pressurized water reactor at the Three Mile Island Nuclear Power Plant in Pennsylvania. [12] The scope and complexity of this reactor accident became clear over the course of five days, as a number of agencies at the local, state and federal levels tried to solve the problem and decide whether the ongoing accident required an emergency evacuation, and to what extent.
The World Nuclear Association has stated that cleanup of the damaged nuclear reactor system at TMI-2 took nearly 12 years and cost approximately US $973 million.[13] Benjamin K. Sovacool, in his 2007 preliminary assessment of major energy accidents, estimated that the TMI accident caused a total of $2.4 billion in property damages.[14] The health effects of the Three Mile Island accident are widely, but not universally, agreed to be very low level.[15][13]
The TMI accident forced regulatory and operational improvements on a reluctant industry, but it also increased opposition to nuclear power.[16] The accident triggered protests around the world.[17]
Date | Location | Description | Fatalities | Cost (in millions 2006 US$) |
INES rating |
---|---|---|---|---|---|
July 26, 1959 | Simi Valley, California, USA | Partial core meltdown at Santa Susana Field Laboratory’s Sodium Reactor Experiment | 0 | 32 | |
January 3, 1961 | Idaho Falls, Idaho, US | Explosion at National Reactor Testing Station | 3 | 22 | |
October 5, 1966 | Monroe, Michigan, USA | Sodium cooling system malfunctions at Enrico Fermi demonstration breeder reactor causing partial core meltdown | 0 | 19 | |
July 16, 1971 | Cordova, Illinois, USA | An electrician is electrocuted by a live cable at the Quad Cities Unit 1 reactor on the Mississippi River | 1 | 1 | |
August 11, 1973 | Palisades, Michigan, USA | Steam generator leak causes manual shutdown of pressurized water reactor | 0 | 10 | |
March 22, 1975 | Browns Ferry, Alabama, USA | Fire burns for seven hours and damages more than 1600 control cables for three nuclear reactors at Browns Ferry, disabling core cooling systems | 0 | 240 | |
November 5, 1975 | Brownsville, Nebraska, USA | Hydrogen gas explosion damages the Cooper Nuclear Facility’s Boiling Water Reactor and an auxiliary building | 0 | 13 | |
June 10, 1977 | Waterford, Connecticut, USA | Hydrogen gas explosion damages three buildings and forces shutdown of Millstone-1 Boiling Water Reactor | 0 | 15 | |
February 4, 1979 | Surry, Virginia, USA | Surry Unit 2 shut down in response to failing tube bundles in steam generators | 0 | 12 | |
March 28, 1979 | Middletown, Pennsylvania, US | Loss of coolant and partial core meltdown, see Three Mile Island accident and Three Mile Island accident health effects | 0 | 2,400 | |
November 22, 1980 | San Clemente, California, USA | Worker cleaning breaker cubicles at San Onofre Pressurized Water Reactor contacts an energized line and is electrocuted | 1 | 1 | |
February 26, 1982 | San Clemente, California, USA | Southern California Company shuts down San Onofre Unit 1 out of concerns about earthquake | 0 | 1 | |
March 20, 1982 | Lycoming, New York, USA | Recirculation system piping fails at Nine Mile Point Unit 1, forcing two year shutdown | 0 | 45 | |
March 25 1982 | Buchanan, New York, USA | Damage to steam generator tubes and main generator resulting in a shut down Indian Point Energy Center Unit 3 for more than a year | 0 | 56 | |
June 18, 1982 | Senaca, South Carolina, USA | Feedwater heat extraction line fails at Oconee 2 Pressurised Water Reactor, damaging thermal cooling system | 0 | 10 | |
February 12, 1983 | Fork River, New Jersey, USA | Oyster Creek Nuclear Power Plant fails safety inspection, forced to shut down for repairs | 0 | 32 | |
February 26, 1983 | Fort Pierce, Florida, USA | Damaged thermal shield and core barrel support at St Lucie Unit 1, necessitating 13-month shutdown | 0 | 54 | |
September 15, 1984 | Athens, Alabama, US | Safety violations, operator error, and design problems force six year outage at Browns Ferry Unit 2 | 0 | 110 | |
March 9, 1985 | Athens, Alabama, US | Instrumentation systems malfunction during start-up, which led to suspension of operations at all three Browns Ferry Units | 0 | 1,830 | |
April 11, 1986 | Plymouth, Massachusetts, US | Recurring equipment problems force emergency shutdown of Boston Edison’s Pilgrim Nuclear Power Plant | 0 | 1,001 | |
March 31, 1987 | Delta, Pennsylvania, US | Peach Bottom units 2 and 3 shutdown due to cooling malfunctions and unexplained equipment problems | 0 | 400 | |
July 15, 1987 | Burlington, Kansas, USA | Safety inspector dies from electrocution after contacting a mislabeled wire | 1 | 1 | |
December 19, 1987 | Lycoming, New York, US | Malfunctions force Niagara Mohawk Power Corporation to shut down Nine Mile Point Unit 1 | 0 | 150 | |
March 29, 1988 | Burlington, Kansas, USA | A worker falls through an unmarked manhole and electrocutes himself when trying to escape | 1 | 1 | |
September 10, 1988 | Surry, Virginia, USA | Refuelling cavity seal fails and destroys internal pipe system at Surry Unit 2, forcing 12-month outage | 0 | 9 | |
March 5, 1989 | Tonopah, Arizona, USA | Atmospheric dump valves fail at Palo Verde Unit 1, leading to main transformer fire and emergency shutdown | 0 | 14 | |
March 17, 1989 | Lusby, Maryland, US | Inspections at Calvert Cliff Units 1 and 2 reveal cracks at pressurized heater sleeves, forcing extended shutdowns | 0 | 120 | |
November 17, 1991 | Scriba, New York, USA | Safety and fire problems force shut down of the FitzPatrick nuclear reactor for 13 months | 0 | 5 | |
April 21, 1992 | Southport, North Carolina, USA | NRC forces shut down of Brunswick Units 1 and 2 after emergency diesel generators fail | 0 | 2 | |
February 3, 1993 | Bay City, Texas, USA | Auxiliary feed-water pumps fail at South Texas Project Units 1 and 2, prompting rapid shutdown of both reactors | 0 | 3 | |
February 27, 1993 | Buchanan, New York, USA | New York Power Authority shuts down Indian Point Energy Center Unit 3 after AMSAC system fails | 0 | 2 | |
March 2, 1993 | Soddy-Daisy, Tennessee, USA | Equipment failures and broken pipes cause shut down of Sequoyah Unit 1 | 0 | 3 | |
December 25, 1993 | Newport, Michigan, USA | Shut down of Fermi Unit 2 after main turbine experienced major failure due to improper maintenance | 0 | 67 | |
14 January 1995 | Wiscasset, Maine, USA | Steam generator tubes unexpectedly crack at Maine Yankee nuclear reactor; shut down of the facility for a year | 0 | 62 | |
May 16, 1995 | Salem, New Jersey, USA | Ventilation systems fail at Salem Units 1 and 2 | 0 | 34 | |
February 20, 1996 | Waterford, Connecticut, US | Leaking valve forces shutdown Millstone Nuclear Power Plant Units 1 and 2, multiple equipment failures found | 0 | 254 | |
September 2, 1996 | Crystal River, Florida, US | Balance-of-plant equipment malfunction forces shutdown and extensive repairs at Crystal River Unit 3 | 0 | 384 | |
September 5, 1996 | Clinton, Illinois, USA | Reactor recirculation pump fails, prompting shut down of Clinton boiling water reactor | 0 | 38 | |
September 20, 1996 | Senaca, Illinois, USA | Service water system fails and results in closure of LaSalle Units 1 and 2 for more than 2 years | 0 | 71 | |
September 9, 1997 | Bridgman, Michigan, USA | Ice condenser containment systems fail at Cook Units 1 and 2 | 0 | 11 | |
May 25, 1999 | Waterford, Connecticut, USA | Steam leak in feed-water heater causes manual shutdown and damage to control board annunicator at the Millstone Nuclear Power Plant | 0 | 7 | |
September 29, 1999 | Lower Alloways Creek, New Jersey, USA | Major Freon leak at Hope Creek Nuclear Facility causes ventilation train chiller to trip, releasing toxic gas and damaging the colling system | 0 | 2 | |
February 16, 2002 | Oak Harbor, Ohio, US | Severe corrosion of control rod forces 24-month outage of Davis-Besse reactor | 0 | 143 | |
January 15, 2003 | Bridgman, Michigan, USA | A fault in the main transformer at the Donald C. Cook nuclear power plant causes a fire that damages the main generator and back-up turbines | 0 | 10 | |
June 16, 2005 | Braidwood, Illinois, USA | Exelon’s Braidwood nuclear station leaks tritium and contaminates local water supplies | 0 | 41 | |
August 4, 2005 | Buchanan, New York, USA | Entergy’s Indian Point Energy Center Nuclear Plant leaks tritium and strontium into underground lakes from 1974 to 2005 | 30 | ||
March 6, 2006 | Erwin, Tennessee, USA | Nuclear fuel services plant spills 35 litres of highly enriched uranium, necessitating 7-month shutdown | 0 | 98 | |
February 1, 2010 | Vernon, Vermont, US | Deteriorating underground pipes from the Vermont Yankee Nuclear Power Plant leak radioactive tritium into groundwater supplies | 0 | 700 |
Nuclear safety in the U.S. is governed by federal regulations and continues to be studied by the Nuclear Regulatory Commission (NRC). The safety of nuclear plants and materials controlled by the U.S. government for research and weapons production, as well those powering naval vessels, is not governed by the NRC.[19][20]
Following the Fukushima Daiichi nuclear disaster, according to Black & Veatch’s annual utility survey that took place after the disaster, of the 700 executives from the US electric utility industry that were surveyed, nuclear safety was the top concern.[21] There are likely to be increased requirements for on-site spent fuel management and elevated design basis threats at nuclear power plants.[22][23] License extensions for existing reactors will face additional scrutiny, with outcomes depending on the degree to which plants can meet new requirements, and some of the extensions already granted for more than 60 of the 104 operating U.S. reactors could be revisited. On-site storage, consolidated long-term storage, and geological disposal of spent fuel is "likely to be reevaluated in a new light because of the Fukushima storage pool experience".[22]
In October 2011, the Nuclear Regulatory Commission instructed agency staff to move forward with seven of the 12 safety recommendations put forward by the federal task force in July. The recommendations include "new standards aimed at strengthening operators’ ability to deal with a complete loss of power, ensuring plants can withstand floods and earthquakes and improving emergency response capabilities". The new safety standards will take up to five years to fully implement.[24]