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NUCLEAR FACTS

Business of nuclear

U.S. nuclear power plant performance

Key Facts
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In 1999, nuclear energy generated more electricity-728 billion kilowatt-hours-in the United States than any other fuel source except coal.

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In 1999, U.S. nuclear power plants achieved an average capacity factor of 86.8 percent. (Capacity factor measures the amount of electricity actually produced compared with the maximum output achievable.) The 1999 average is 29 percentage points higher than the 1980 average.

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In 1999, 95 percent of U.S. nuclear power plants achieved a capacity factor of 70 percent or higher. Excluding the two units that did not operate at all during the year, 97 percent of America's nuclear power plants achieved capacity factors of 70 percent or higher. In 1980, only 19 percent of U.S. nuclear power plants operated at that level.

Record-breaking performance propels industry into 21st century
Since 1980, more than 40 U.S. nuclear power plants have entered service. The number of nuclear power plants in commercial service now stands at 103, up from 68 in 1980.

U.S. nuclear power plant performance reached an all-time high in 1999. Power plant performance is commonly measured by capacity factor, which expresses the amount of electricity actually produced by a plant compared with the maximum achievable. U.S. nuclear power plants achieved a record capacity factor of 86.8 percent in 1999, significantly higher than the 1980 average of 57.6 percent. Excluding the two plants that didn't operate last year, the 1999 average capacity factor for the remaining plants was 88.5 percent.

Ninety-seven percent of U.S. nuclear plants operated at a capacity factor of 70 percent or better; only 19 percent achieved that level in 1980. Eighty-seven percent had a capacity factor of 80 percent or higher in 1999, compared with only 6 percent in 1980.

Nationally, each percentage point increase in capacity factor is roughly equivalent to bringing another 1,000 megawatts of generating capacity on line. Improved nuclear power plant performance thus helps meet the growing demand for electricity in the United States.

In 1999, nuclear power plants provided 728 billion kilowatt-hours, one-fifth of the electricity generated in the United States. The rise in capacity factor over the past decade is the result of plant modifications, improved operating and maintenance practices, and more attention to training of nuclear plant personnel.

Drive for excellence
During the 1980s, U.S. utilities committed to a major nuclear power plant improvement program. Its success is partly due to the initiatives of the Institute of Nuclear Power Operations (INPO). INPO is an industry-sponsored organization that evaluates U.S. nuclear power plants and sets goals for excellence in operations.

As part of its program, INPO monitors 10 key performance indicators, such as unplanned automatic shutdowns, safety system performance and industrial safety. The World Association of Nuclear Operators (WANO) collects U.S. industry data on these performance indicators and shares this information with INPO members. Each of the performance indicators reveals significant improvement since 1980.

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Unit capability factor is the percentage of maximum energy generation a plant is capable of supplying. In 1999, the industry's unit capability factor hit an all-time high of 88.7 percent—up from 87 percent in 1998 and exceeding the industry's year 2000 goal. U.S. nuclear power plants' unit capability factor has risen 26 percentage points since 1980—a 41 percent jump.

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Unplanned automatic scrams are plant shutdowns caused by some imbalance in operations. They are measured for 7,000 hours of operation (about one year). For the third consecutive year, the industry's median value was zero, thanks to the fact that nearly two-thirds of operating plants had no unplanned scrams. Fewer shutdowns save consumers money by eliminating utilities' need to buy replacement power and point to the effectiveness of utility training and maintenance programs.

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Thermal performance monitors how efficiently a plant converts thermal energy into electrical output. Similar to a car getting more miles per gallon of gasoline, a lower thermal performance figure signifies greater plant efficiency. This "heat rate" has fallen from 10,504 Btu to produce a kilowatt-hour of electricity in 1980 to 10,082 Btu in 1999.

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Collective radiation exposure has trended downward since 1980 at both boiling water reactors (BWRs) and pressurized water reactors (PWRs). At BWRs, radiation exposures fell from 859 man-rem per unit in 1980 to 172 in 1999. At PWRs, exposures fell from 417 man-rem per unit in 1980 to a record low of 98 in 1999. The declines show the effectiveness of radiological protection programs. 

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Industrial safety accident rates have seen a near tenfold improvement since 1980. Industrial accidents now number 0.34 per 200,000 worker-hours, making the commercial nuclear energy industry one of the safest places to work in America. By comparison, the accident rate for U.S. private industry was 2.3 per 200,000 worker-hours in 1998—the last year figures are available from the U.S. Bureau of Labor Statistics.

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Volume of solid low-level radioactive waste produced both by PWRs and BWRs was less than the industry's goals for the year 2000. Low-level waste volume from PWRs averaged 22 cubic meters in 1999, substantially better than the 500 cubic meters produced in 1980. The typical BWR generated 85 cubic meters of low-level waste in 1999, down from 950 cubic meters in 1980

Nuclear electricity: Becoming more competitive
The nuclear industry is a mature business. Nuclear power plants are operating more safely, more productively and more competitively. Since 1980, the industry has made significant changes in the way it operates nuclear power plants. These changes, which required increased staffing and safety improvement work, boosted plant performance, reliability and output. At the same time, they pushed up operating and maintenance (O&M) costs.

As these changes became institutionalized in utility programs, however, O&M costs stabilized. Average O&M costs for nuclear plants—measured in 1998 dollars—were 1.83 cents/kWh in 1990, 1.44 cents in 1995 and 1.35 cents in 1998 (latest data available), based on figures from the Utility Data Institute, an independent research organization. Moreover, nuclear energy is competitive with other sources of electricity. With average production costs—O&M plus fuel—of 2.13 cents/kWh in 1998, nuclear is only marginally more costly than coal at 2.07 cents/kWh, and considerably less expensive than natural gas at 3.30 cents/kWh and oil at 3.24 cents/kWh.

To help improve efficiency, the U.S. nuclear energy industry has created mechanisms to share good economic practices. A major industrywide benchmarking program was launched in 1995 to study work management and outage management practices at top-performing plants both in the United States and overseas.

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