The following story originally appeared in NEI’s Nuclear Energy Overview.
U.S. nuclear energy facilities recorded the lowest number of unplanned shutdowns in more than a decade last year, despite an unusually high number of natural disasters near several plants.
According to performance indicators compiled by the World Association of Nuclear Operators (WANO) and the Institute of Nuclear Power Operations (INPO), the 62 unplanned automatic and manual shutdowns in 2011—even after tornadoes in the Southeast, flooding in the Midwest, an earthquake in Virginia and Hurricane Irene—bested the previous record of 65 set in 2005.
The achievement allowed the nuclear industry to sustain its decade-long high levels of reliability, with a 10th straight year of capability factors above 91 percent. The industry also attained record levels of industrial safety in 2011, placing it among the best in U.S. Bureau of Labor Statistics rankings.
“America’s nuclear energy facilities performed extremely well in the face of a host of natural challenges,” said Tony Pietrangelo, NEI’s senior vice president and chief nuclear officer. “The industry’s employees can take pride in this achievement while recognizing that their commitment to safety and excellence must never waver.”
Among the notable results for 2011:
- Reactor capability factor, a measure of a plant’s on-line electricity production time, exceeded 91 percent for the 10th year. Capacity factor, a related metric that measures total electricity generated as a percentage of year-round potential generation, was 89 percent in 2011, according to data compiled by the U.S. Energy Information Administration.
- U.S. nuclear plants posted the lowest industrial accident rate in 2011 in more than a decade, at 0.06 accidents per 200,000 workers. There were 0.09 accidents per 200,000 workers in 2010. The figure is also significantly lower than the 2015 target of 0.10 accidents per 200,000 workers. Bureau of Labor Statistics records show that workers suffered fewer accidents at nuclear energy facilities than in a wide range of other fields, including the manufacturing, real estate and financial sectors of the economy.
- For the 13th straight year, each of three principal backup safety systems that the industry monitors at every reactor met their “near-100 percent availability” goals more than 90 percent of the time, assuring that multiple layers of safety are in place as designed. The systems monitored are two main cooling systems and backup power supplies used to respond to unusual situations.
- The industry had 62 unplanned automatic and manual shutdowns in 2011, the lowest number in the last 12 years. INPO changed its methodology this year, counting automatic and manual shutdowns together rather than separately.
“These 2011 safety and performance indicators provide overwhelming evidence of the resiliency of our plants in confronting weather challenges and confirm the unwavering commitment of the industry’s dedicated men and women to safe and efficient operations,” said Pietrangelo.
WANO, headquartered in the United Kingdom, compiles nuclear energy industry performance data annually. Data for the U.S. industry is analyzed by the Atlanta-based INPO, which helps set benchmarks of excellence against which safety and plant operation are measured.
A full set of charts of the 2011 WANO performance indicators for U.S. nuclear power plants may be found here.










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