Nuclear Reliability

Power You Can Count On

Nuclear energy is the only large-scale power source that can be tapped in even the most extreme weather conditions, 24 hours a day, 7 days a week. Constellation’s nuclear facilities are built to withstand tornados, hurricanes, floods, heat waves and droughts, and even record-breaking winter snow and ice. During the 2014 polar vortex, demand for energy surged. Nuclear facilities performed when other plants did not.

We do this day in and day out, without emitting carbon dioxide, sulfur dioxide, or nitrogen oxides as part of the power generation process. In fact, nuclear power plants produce more than 60% of the nation's clean energy, more than all other clean-energy sources combined.

Thanks to nuclear power, Constellation makes sure electricity is there when you need it. Nuclear plants only need to be refueled every 18 to 24 months, and Constellation has the fastest refueling time in the business. Our 2021 average refueling outage duration was 22 days, 11 days better than the industry average. It's another way we achieve industry-leading reliability.

The fuel we need to keep your power on is right here, on site. We don't depend on on-time shipments, clear roads, or cooperative weather conditions. A polar vortex or extreme heat won't stop us from producing power when it's needed most.

Continue reading to learn more about Constellation’s nuclear reliability.

Constellation spends millions each year on capital projects and upgrades to improve and modernize equipment. This ensures reliable plant operations, enhances safety, and supports state-of-the-art facilities.

One way the industry measures reliability is by capacity factor, or the amount of up-time when a plant is producing power, up to 100%. In 2021, Constellation’s nuclear capacity factor was 94.5%, the highest in the industry.

Constellation technical experts at our nuclear facilities regularly perform tens of thousands of tasks every year: equipment upgrades, extensive safety inspections and tests, and plant improvements. We meticulously disassemble, inspect, reassemble, and test reactor components.

Nuclear energy uses uranium, a naturally occurring and abundant element, as its fuel. There’s an ample supply, making it low-cost.

Uranium is also incredibly efficient. One uranium fuel pellet, about the size of the tip of an adult’s pinkie finger, produces the same amount of energy as 126 gallons of oil, 17,000 cubic feet of natural gas, or one ton of coal.

To further ensure dependable, responsible, and affordable sources of uranium, Constellation is part of the Ad Hoc Utilities Group (AHUG), which supports a fair, global market for uranium supply. Learn more about AHUG and its mission at