Duke Energy’s Nuclear Fleet Braves 2015 Cold Snap


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.

What are Small Modular Nuclear Reactors?

Small Modular Nuclear Reactors (SMRs) are nuclear power plants that are smaller in size than most commercial nuclear power plants today. The plants in the Duke Energy nuclear fleet are large baseload power plants, which mean they are designed to provide a steady amount, or base, of power around the clock.  All of Duke’s reactors are more than 800 megawatts in size; SMRs are 300 megawatts or less. But it is that smaller size that makes them attractive options for the future.

One of the biggest potential advantages of SMRs is their cost. Because of the smaller, more compact design, SMRs require less of a footprint than today’s baseload nuclear power plants. That means reduced siting costs.

The SMRs are designed to be factory built and transported by truck or rail to a nuclear power site. This production would result in economies of scale that can benefit all buyers – an advantage not possible with larger, customized nuclear plants.

SMRs could be used to provide power to locales, including remote sites, where smaller power capacity is all that’s required to meet load requirements.

Many SMRs are designed with improved safety and security features. Their reactor buildings, fuel pools and control rooms are housed underground to withstand earthquakes, tsunamis, tornadoes, hurricanes and terrorist threats.

While they are not envisioned to replace existing nuclear plants in the future, they may help replace some of the power produced by today’s fossil fuel plants, and their emergency planning zone is designed to be no more than about a 300 meter radius.

To help ensure the continued development of SMRs and other clean energy options for the future, the U.S. Department of Energy is helping accelerate the timelines for the commercialization and deployment of SMR technologies. Several manufacturers currently have SMR designs in the works, and the Nuclear Regulatory Commission anticipates it may receive the first applications for review by late 2015.

Outage workers boost local economies

OutageEach spring visitors of a special kind arrive in the sleepy little coastal town of Southport, N.C.  These visitors come with great purpose and bring with them a mini-economic boom for this small town and many others like it across the entire country.

Southport, a town of 3,000 residents, is accustomed to visitors. Each year the population swells as tourists flock to the area for summer vacations. Situated at the mouth of the Cape Fear River, Southport is a hub of activity for those headed to Bald Head Island, the nearby island community known for its affluent clientele, or Oak Island that sits across the intracoastal waterway. The tourists give the area a massive economic boost with estimates of well over 100,000 people visiting the area each year. That impact is typically limited to the time frame between Memorial Day and Labor Day, creating a vibrant summertime  village with busy art galleries and restaurants.

During the remainder of the year, the town resembles any other small town in North Carolina with residents going about their normal routine. But because Southport is home to one of Duke Energy’s nuclear power plants, the town enjoys extra benefits, including well-paying jobs and a stable tax base that supports the entire county. Each spring, when the plant shuts down for refueling and maintenance, additional temporary jobs come open and local businesses enjoy the influx of outage workers.

Outage season typically lasts for 30-60 days and brings both challenges and benefits. Although the number of workers fluctuates each year, the arrival of these workers stimulates the local economy, especially for businesses offering services such as lodging, dining and entertainment. Residents notice increased traffic and might have to call ahead for reservations at their local restaurants, but most recognize more upsides than down.

Quantifying the impact of outage season is challenging, but the Nuclear Energy Institute  has taken some of the best data from across the country to build a generic model of how outages  stimulate local economies. In Southport, the local hotels and motels report near capacity occupancy rates, while the restaurants introduce special hours designed to attract outage workers. As one resident puts it, “you can tell it is outage season when you see specials starting at 7 a.m.” When you consider the larger picture, there are about 100 towns just like Southport across the country that benefit when  outage workers arrive.

During a typical outage, workers at the plant will replace approximately one-third of the fuel, conduct inspections and make repairs and upgrades. Some of the work is highly specialized but there are also jobs for welders, pipe-fitters and crane operators.  Unlike the more stereotypical construction worker, nuclear outage workers are a special breed who understand the unique environment they work in, the importance of safety and why utilities work to complete the work as efficiently as possible.  Outage workers have to pass a series of background checks and investigations to earn the chance to work at a nuclear plant.