U.S. nuclear power efficiency up in 2014

TVA's Sequoyah Unit 1 nuclear reactor near Soddy-Daisy generated electricity 99.6 percent of the year during 2014.

Generating more power

TVA's nuclear plants boosted the share of time they produced maximum power during 2014 to one of the highest capacity factor rates ever. TVA reactors ranked in order of their capacity factor performances last year were: * Sequoyah Unit 1 -- 99.6 percent * Browns Ferry 2 -- 98 percent * Browns Ferry 1 -- 90.1 percent * Sequoyah 2 -- 89.6 percent * Watts Bar 1 -- 89.3 percent * Browns Ferry 3 -- 88.5 percent Source: Nuclear Energy Institute analysis of Nuclear Regulatory Commission monthly operating reports. The average for all 100 operating nuclear reactors operating in 31 states was 91.9 percent, the highest capacity factor ever.

U.S. nuclear power plants generated electricity at a record high level of efficiency last year and the Tennessee Valley Authority averaged slightly better than the industry as a whole, according to operating reports filed with nuclear regulators.

The Nuclear Energy Institute, an industry trade group for the nuclear industry, calculates that the 100 nuclear reactors operating in the United States generated power 91.9 percent of the year during 2014. TVA's six nuclear reactors ranged from a capacity factor of 88.5 percent at the newest reactor at Browns Ferry in Alabama up to 99.6 percent at the oldest reactor at the Sequoyah plant near Soddy-Daisy.

Actual electricity production from nuclear power plants in 2014 was the sixth highest year ever with an estimated 798.4 billion kilowatthours of power generation. The industry's record generation was in 2010 when 104 reactors were operating. But four American reactors have shut down in the past four years.

"Our refueling outages have gone from three months to one month and plant technology and processes have gotten better over time to help keep plants on line more of the time," David Bradish, the manager of energy and economic analysis at the Nuclear Energy Institute, said Friday. "Plants are running much better and more reliably than they ever have, which makes nuclear power that much more cost efficient for utilities."

NEI spokesman Mitch Singer said much of the maintenance and repair work on nuclear plants that previously was only done during outages can now be performed while the plant is online and generating power.

Bradish said when U.S. nuclear plants first were built in the 1960s, '70s and '80s, they typically operated only 50 to 60 percent of the time. Unplanned outages and refueling and maintenance work typically kept plants offline or at reduced power one third or more of the year.

TVA was forced in 1988 to idle its entire nuclear power fleet for several years when employee and regulatory concerns were voiced about the safety of TVA's operating plants at the Browns Ferry and Sequoyah nuclear plants and construction work then underway at the Watts Bar and Bellefonte plants. TVA spent the next eight years repairing and completing work at Browns Ferry, Sequoyah and Watts Bar.

TVA had a number of unplanned outages at its plants three years ago when the NRC put Browns Ferry and Watts Bar on a watch list. But TVA since has improved the reliability of its operating nuclear plants. The Sequoyah Unit 1 reactor operated 99.6 percent of the time at maximum power during 2014, according to NRC reports.

Nuclear power plants have the highest capacity factors of any major power generation source. Coal and natural gas plants often run 50 percent to 70 percent of their capacity because their power output is frequently raised and lowered to match changing consumer demand.

"Once you fire up a nuclear plant, you are pretty much running it at full capacity all the time," TVA spokesman Jim Hopson said. "Nuclear power is our second cheapest source of power -- behind only hydroelectric generation from our dams -- so we try to run our nuclear units as much as possible. We have continued to improve our performance and, in recent years, we've worked hard as a team to make the changes needed to improve our performance."

Marvin Fertel, president and CEO of the industry-backed Nuclear Energy Institute, said last year's results "show unequivocally how important well-performing nuclear energy is to America's energy security, economy and quality of life."

Nuclear power generates about 20 percent of the electricity produced in America, but that share is not likely to go up much. TVA plans to bring on the first new nuclear reactor in the 21st century when it starts a second reactor by the end of 2015 at the Watts Bar Nuclear Plant near Spring City, Tenn. But at the end of last year, Entergy Corp. shut down its Vermont Yankee nuclear plant.

Southern Co. is building more reactors at Plant Vogtle in Georgia and SCANA is building two more units at the V.C. Summer plant in South Carolina. But other reactors are reaching the end of their licensed life.

Bradish said as nuclear plants have gotten older, utilities have reinvested in new equipment and procedures have gotten better, leading to better performance and better output.

"What we saw in 2014 was a reflection of how well these plants are being maintained and operated," he said.

NEI said 10 nuclear reactors generated above their rated capacity during 2014. The worst performing unit was the Davis Besse plant in Ohio where a reactor vessel head was replaced after a small hole was discovered in 2002.

Contact Dave Flessner at dflessner@timesfreepress.com or at 757-6340.