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Many Safety Indicators Show Record-Best Levels of Excellence at Nuclear Power Plants in 2006

WASHINGTON—America’s nuclear power plants continued to operate at high levels of efficiency and safety in 2006, according to industry performance indicators compiled by the World Association of Nuclear Operators.

For the seventh consecutive year, the U.S. nuclear energy industry’s unit capability factor topped 90 percent. The median capability factor for 103 reactors of 91.5 percent, when measured on an operating cycle basis, was within four-tenths of a percentage point of the 91.9 percent record set in 2005. Unit capability factor is the percentage of electricity actually produced compared to the maximum electricity a plant could supply to the electrical grid.

These sector-leading levels of efficiency at nuclear power plants produced 787.2 billion kilowatt-hours (kwh) of electricity last year, second only to the record-high of 788.5 billion kwh of electricity produced in 2004.

The nuclear energy industry similarly sustained excellent levels of safety and operating performance in areas including safety system performance, industrial safety, unplanned automatic reactor shutdowns, and programs to protect workers from radiation exposure.

“The 2006 performance indicators are another indicator of the nuclear industry’s commitment to safety and efficient operations,” said Frank L. “Skip” Bowman, the Nuclear Energy Institute’s president and chief executive officer. “As our industry prepares to build new state-of-the-art nuclear plants, it’s noteworthy that we move forward from a solid foundation of operating excellence at our existing plants.”

The performance data compiled by WANO is analyzed by the Atlanta-based Institute of Nuclear Power Operations, which promotes excellence in U.S. nuclear power plant safety and operations. INPO uses the data to help set challenging benchmarks of excellence against which safety and plant operation can be measured. New performance indicator goals for 2010 also are shown in the results report for 2006 (link to report provided below), since last year marked the beginning of INPO’s new five-year goal period.

In previous years, results for the performance indicators were based on a calendar year. Beginning in 2006, performance indicators and goals are based on nuclear plants’
lengthier operating cycles between refuelings to more consistently reflect performance.

Results from previous years have been reconfigured to conform to the new methodology. Other highlights of the nuclear energy industry’s performance in 2006 include:

Unplanned Automatic Reactor Shutdowns. The 2006 median industry value of 0.42 unplanned automatic shutdowns per plant equaled the historic low value first established in 2002. The 2006 cycle value also was better than the 2010 median goal of 0.5 unplanned shutdowns per 7,000 hours of reactor operation.

Safety System Performance. For the 12th straight year, 94 percent or more of key safety systems met industry goals for availability. In 2006, 97 percent of the key safety systems met their availability goals. Nuclear power plants are built with redundant 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 key standby safety systems are two main cooling systems and back-up power supplies used to respond in the event of unusual situations.

Forced Capability Loss Rate. The 2006 cycle median value of 1.2 percent capability loss reflects significant progress in the operation of nuclear plants. Ten years ago, the median value exceeded five percent; it has been under two percent each year since 2000. Forced capability loss rate measures a plant’s outage time and power reductions that result from unplanned equipment failures, human errors or other conditions when the plant is expected to be generating electricity. The industry’s 2010 goal for this indicator is a median value of one percent.

Industrial Safety. The nuclear industry is acknowledged as one of the nation’s safest working environments; U.S. nuclear plants continue to post a very low industrial accident rate. In 2006, the industry median plant had only 0.12 industrial accidents per 200,000 worker-hours, a record low. Statistics from other industries through 2005, 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 finance industries.

Collective Radiation Exposure. The industry’s collective radiation performance at both pressurized-water reactors (PWRs) and boiling-water reactors (BWRs) improved from 2005. Employees at BWRs recorded a 9.6 percent decrease in collective exposure (measured as person-rem per reactor), while employees at PWRs recorded a 2.9 percent decrease from the prior year. Low exposure indicates strong management attention to radiation protection.


The Nuclear Energy Institute is the nuclear energy industry’s policy organization. This news release and additional information about nuclear energy are available on NEI’s web site at