Photo provided courtesy of the Nuclear Energy Institute (NEI).In the Carolinas, the fruit trees are blooming and the official start of spring is here. It’s easy to forget that just a month ago winter came in with a vengeance and tested the company’s power delivery system. Record cold temperatures were like an unwanted dinner guest – they came and wouldn’t go away. In such cold weather, electricity demand increases dramatically as customers struggle to stay warm. Duke Energy Carolinas set an all-time record for peak electricity demand at 21,101 megawatt-hours on Feb. 20, 2015, exceeding the previous all-time record of 20,799 megawatt-hours set on Jan. 30, 2014.
The company’s nuclear power plants played a pivotal role in providing power to residential, commercial and industrial customers during the cold snap. The Duke Energy nuclear fleet operated at 100 percent power during the most challenging portion of the February deep freeze, providing 10,679 megawatts of electricity.
The stellar performance of the nuclear fleet is no “accident.” While low fuel cost, minimal greenhouse gas emissions and low environmental impacts are well-known characteristics of nuclear power, its reliability and availability is sometimes overlooked. Nuclear plants are refueled about every 18 months, in contrast to coal or natural gas plants which need a continual supply of natural gas or coal to run. For the most part, nuclear plants operate uninterrupted day and night, rain or shine until the next refueling outage.
The availability of the Duke Energy nuclear plants during the February cold weather was a result of good performance by well-maintained equipment and well-trained personnel. The company places a strong emphasis on equipment reliability through preventive maintenance and early diagnosis of potential equipment problems. As frigid temperatures approached, special measures were taken at each nuclear plant to ensure availability. As soon as company meteorologists identified the looming weather challenge, nuclear teammates began carrying out special actions to cope with the anticipated high demand. Each nuclear site ran through cold weather checklists to ensure key components would not freeze or become inoperable as temperatures plummeted. One site postponed a planned refueling outage, while another delayed system testing and preventive maintenance to help meet demand. Delaying the outage alone provided more than 930 megawatts of electricity to customers when it was needed the most (to learn more about refueling outages, click here to read a previous article).
The 2014 Polar Vortex highlighted the value of nuclear plants in the Midwest and northeast in dealing with extreme cold weather. Similarly, during the extended cold weather in February 2015, the Duke Energy nuclear fleet performed in an exemplary manner to help cope with an unprecedented demand for power. These incidents emphasize the value of generating assets that can supply large quantities of power reliably around the clock and during adverse weather conditions.