Near Misses at U.S. Nuclear Power Plants

The Nuclear Regulatory Commission (NRC) is the arm of the federal government charged with enforcing safety regulations at U.S. nuclear power plants. Every year they respond to safety and security “near misses,” defined as events that increased the risk of reactor core damage by at least 10 times. This series catalogs those near misses.


Grand Gulf: Three Nuclear Safety Miscues in Mississippi Warranting NRC’s Attention

, director, Nuclear Safety Project

The Nuclear Regulatory Commission (NRC) reacted to a trio of miscues at the Grand Gulf nuclear plant in Mississippi by sending a special inspection team to investigate. While none of the events had adverse nuclear safety consequences, the NRC team identified significantly poor performance by the operators in all three. The recurring performance shortfalls instill little confidence that the operators would perform successfully in event of a design basis or beyond design basis accident. Read more >

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Broken Valve in Emergency System at LaSalle Nuclear Plant

, director, Nuclear Safety Project

An NRC Special Inspection Team (SIT) conducted an inspection at the LaSalle Nuclear Plant this spring to investigate the cause of a valve’s failure and assess the effectiveness of the corrective actions taken. Read more >

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Cooper: Nuclear Plant Operated 89 Days with Key Safety System Impaired

, director, Nuclear Safety Project

The Nebraska Public Power District’s Cooper Nuclear Station about 23 miles south of Nebraska City has one boiling water reactor that began operating in the mid-1970s to add about 800 megawatts of electricity to the power grid. Workers shut down the reactor on September 24, 2016, to enter a scheduled refueling outage. That process eventually led to NRC special inspections. Read more >

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Turkey Point: Fire and Explosion at the Nuclear Plant

, director, Nuclear Safety Project

The Florida Power & Light Company’s Turkey Point Nuclear Generating Station about 20 miles south of Miami has two Westinghouse pressurized water reactors that began operating in the early 1970s. Built next to two fossil-fired generating units, Units 3 and 4 each add about 875 megawatts of nuclear-generated electricity to the power grid.

Both reactors hummed along at full power on the morning of Saturday, March 18, 2017, when problems arose. Read more >

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Palo Verde: Running Without a Backup Power Supply

, director, Nuclear Safety Project

The Arizona Public Service Company’s Palo Verde Generating Station about 60 miles west of Phoenix has three Combustion Engineering pressurized water reactors that began operating in the mid 1980s. In the early morning hours of Thursday, December 15, 2016, workers started one of two emergency diesel generators (EDGs) on the Unit 3 reactor for a routine test. The EDGs are the third tier of electrical power to emergency equipment for Unit 3. Read more >

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