Nuclear reactor accidents in the United States

According to a recent survey in the journal Energy Policy, there have been 45 nuclear accidents in the United States. 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.

Context

Globally, sixty-three accidents have occurred at nuclear power plants. Twenty-nine of these have occurred since the Chernobyl disaster, and 71 percent of all nuclear accidents (45 out of 63) occurred in the United States. 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.

History

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. 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".

Nuclear 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. There was also a partial meltdown at the Enrico Fermi Nuclear Generating Station in Michigan in 1966.

The large size of nuclear plants 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.

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. These men were engineers who had spent most of their working life building reactors, and their defection galvanized anti-nuclear groups across the country. 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.

Three Mile Island accident

President Jimmy Carter leaving Three Mile Island for Middletown, Pennsylvania, April 1, 1979

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. 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. 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. The health effects of the Three Mile Island accident are widely, but not universally, agreed to be very low level. The accident triggered protests around the world.

The accident forced regulatory and operational improvements on a reluctant industry, but it also increased opposition to nuclear power.

List of accidents

See also: Lists of nuclear disasters and radioactive incidents

Nuclear power plant accidents in the U.S.
with fatalities or more than US$50 million in property damage, 1952-2010

Date	Location	Description	Fatalities	Cost (in millions 2006 US$)
January 3, 1961	Idaho Falls, Idaho, US	Explosion at National Reactor Testing Station	3	22
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
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 Onofre, California, USA	Worker cleaning breaker cubicles at San Onofre Pressurized Water Reactor contacts an energised line and is electrocuted	1	1
March 25 1982	Buchanan, New York, USA	Damage to steam generator tubes and main generator resulting in a shut down Indian Point Unit 3 for more than a year	0	56
February 26, 1983	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 startup, 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 mislabelled 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
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
December 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
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
February 16, 2002	Oak Harbor, Ohio, US	Severe corrosion of control rod forces 24-month outage of Davis-Besse reactor	0	143
February 1, 2010	Montpelier, Vermont, US	Deteriorating underground pipes from the Vermont Yankee Nuclear Power Plant leak radioactive tritium into groundwater supplies	0	700

This list is incomplete; please help to expand it.

Nuclear safety

Nuclear safety in the United States 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.

Licensees (organizations applying for construction licenses or operating licenses for nuclear facilities) are required to show before the license is issued that they meet the requirements of the regulations.