Bloomberg Business Week reported yesterday:
Nuclear-power production in the U.S. is at the lowest seasonal levels in nine years as drought and heat force reactors from Ohio to Vermont to slow output.
Generation for the 104 plants in the U.S. fell 0.4 percent from yesterday to 94,171 megawatts, or 93 percent of capacity, the lowest level for this time of year since 2003, according to reports from the U.S. Nuclear Regulatory Commission and data compiled by Bloomberg. The total is down 2.6 percent from the five-year average for today of 96,725 megawatts.
Among the plants limiting output because of the heat are Perry in Ohio and Vermont Yankee:
FirstEnergy Corp.’s Perry 1 reactor in Ohio lowered production to 95 percent of capacity today because of above- average temperatures, while Entergy Corp.’s Vermont Yankee has limited output four times this month. Nuclear plants require sufficient water to cool during operation, and rivers or lakes may get overheated or fall in times of high temperatures and drought, according to the NRC.
The weather forecast is not good for at least one of the affected plants:
Production at FirstEnergy’s 1,261-megawatt Perry 1 reactor dropped by 63 megawatts early today in preparation for high temperatures and humidity, according to Todd Schneider, a company spokesman in Akron, Ohio.
The region is under a weather advisory from noon to 7 p.m. today, with heat index values as high as 102 degrees, according to a report from AccuWeather Inc. Perry 1, 35 miles northeast of Cleveland, has slowed production four times since July 1.
Byron nuclear in Illinois has also been affected by the hot weather:
Generation at the 1,164-megawatt Byron 1 reactor slowed to 80 percent of capacity today, while Byron 2 operated at 84 percent. Production has fluctuated because adjustments to cooling tower operations vary with weather conditions, Paul Dempsey, communications manager at the plant, said by phone from Byron, Illinois.
The Midwest and the Northeast are not the only areas where power has been reduced:
Production in the Southeast was 4.9 percent lower than a year earlier, compared with 6.6 percent for the Midwest and 4.1 percent for the West, according to commission data.
Here’s a link to the Bloomberg article: http://www.businessweek.com/news/2012-07-26/heat-sends-u-dot-s-dot-nuclear-power-production-to-9-year-low