US nuclear plants: Exceptionally safe

Published on: 

New evidence of the safe, reliable operating performance that has made nuclear energy a proven provider of low-cost electricity for American families and businesses has come with the release of 2010 safety and operations data for the U.S. nuclear energy industry by the World Association of Nuclear Operators (WANO).

In 2010, U.S. nuclear power plants remained one of the safest industrial working environments and overall safety performance was sustained at historically high levels, according to performance indicators compiled by WANO.


Among the notable results:

  • For the 12th straight year, more than 90 percent of three important backup safety systems that the industry monitors at every reactor met their "near-100 percent availability" goals;

  • Reactor capability factor, a measure of a plant's on-line electricity production time, exceeded 91 percent for the 10th straight year; and

  • The median value of unplanned automatic plant shutdowns per 7,000 hours of operation was the second lowest on record.

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 Institute of Nuclear Power Operations to help set challenging benchmarks of excellence against which safety and plant operation can be measured. INPO was established by the U.S. nuclear energy industry in 1979 to promote excellence in safety and operating performance above and beyond federal regulatory requirements.

Highlights of the nuclear energy industry's performance in 2010 include:

Safety System Performance. For the 12th straight year, key backup safety systems concurrently met their individual availability goals more than 90 percent of the time. Nuclear power plants are built with multiple safety systems and backup power supplies so these systems are available, if needed, even when maintenance is being performed on a similar system or component. The three principal backup safety systems are two main cooling systems and back-up power supplies used to respond in the event of unusual situations. Each system at every plant has an availability goal just shy of 100 percent, and 93 percent of these backup safety systems met their individual goal, assuring that multiple layers of safety were in place as designed.

Industrial Safety. The nuclear industry is one of the nation's safest working environments. U.S. nuclear plants continued to post a low industrial accident rate in 2010 with 0.09 industrial accidents per 200,000 worker-hours, the lowest level in a decade and well below the 2010 goal of 0.2. Statistics from other industries through 2009, as compiled by the Bureau of Labor Statistics, show that it is safer to work at a nuclear power plant than in the manufacturing sector and even the real estate and financial sectors.

Unplanned Automatic Reactor Shutdowns. The 2010 median industry value was 0.21 unplanned automatic shutdowns per plant per 7,000 hours of reactor operation. This was the second-lowest level achieved in the past 10 years.

Forced Capability Loss Rate. The 2010 median value of 1.5 percent capability loss remained near historically best levels. Forced capability loss rate measures a plant's outage time and power reductions that result from unplanned equipment failures, human error or other conditions when the plant is expected to be generating electricity. The 2010 goal for this indicator is a median value of one percent. In the mid-1990s, the median value exceeded five percent, but it has been under two percent each year since 2001 and 1.5 percent or lower for six consecutive years.

Reactor Capability. America's 104 reactors continued to operate at high levels of efficiency -- far above other electricity sources. On average, U.S. reactors produced electricity 91.4 percent of the time around the clock. This was the 10th straight year the capability factor exceeded 91 percent. Capacity factor, a related metric that measures total electricity generated as a percentage of year-round potential generation, was 91.1 percent in 2010, according to data compiled by the Nuclear Energy Institute.