Byron’s 40-year-old nuclear plant to undergo $355M project to increase power output

BYRON — Constellation Energy, owner of the Byron Nuclear Power Station, plans to invest about $355 million in a lengthy project that will increase the site’s power output and extend the life of the facility and its equipment.

The Power Uprate Project, planned to begin in 2026 and finish in 2029, will replace six low-pressure turbines and two high-pressure turbines. The new turbines will generate an additional 79 to 80 megawatts of energy and part of the project will be updating the electrical system to accommodate that increase, Byron Site Vice President Harris Welt said.

ExpandAutoplay

Image 1 of 15

Paul Dempsey, Generation Communications Manager for Constellation, gestures at the cooling tower of Plant 2 at the Byron nuclear power facility Wednesday, April 16, 2025. The plant, one of two at the station, was shut down for refueling. (Alex T. Paschal)

Although the project will increase its power output, it’s really going to improve the efficiency of the plant because the new turbines are larger, which therefore will spin faster and generate more energy, Welt said.

Power plants – whether nuclear, wind or other types – feed electricity into a grid that then distributes power to various users.

Currently, the Byron power station produces 2,347 megawatts of energy, which is equivalent to the energy needed to power more that 1.7 million homes. With the new turbines, that output will jump up to about 2,427 megawatts.

“It’s very exciting. A lot of planning that’s been going on the last couple years,” Project Manager Justin Shippert said.

The work will start with installing the low-pressure turbines. Each one will be lowered in using two cranes attached to the ceiling. Typically, it’d only take one crane but since each turbine weighs upwards of 350 pounds, it will require both, Shippert said.

Typically, the Byron site has 693 employees. The upgrades will bring in an additional 600 contractional employees during four construction windows. On top of that, the station is currently undergoing an outage at one of its two plant units, bringing in about 1,500 more employees.

All those extra workers in the area means that hotels will fill up and extra business for local restaurants and bars. In Byron, during outages, many restaurants open at 5 a.m. to catch workers getting off for the shift change, said Paul Dempsey, generation communications manager at Constellation.

An outage is when the plant unit shuts down to replace a third of the fuel in the reactor. It’s done for each reactor every 18 months – in 2025 there’s one outage for unit 2, in 2026 there’s two outages for unit 1 and 2, and in 2027 there’s one outage for unit 1, Dempsey said.

Each outage differs in length depending on what kind of work is being done. Sometimes it can last 17 days; other times it can be over 20, he said.

The 2025 outage is planned step by step and encompasses about 10,000 tasks, Welt said.

“It’s really quite amazing. It’s scripted to the hour,” Welt said.

The uprate project will be carefully planned by the hour as well.

Unlike wind or solar energy, the nuclear power station consistently runs 96% of the time at full power, Dempsey said.

“We always want to be online,” Dempsey said.

The 2025 outage marks 40 years since that plant went online in 1985 and 50 years since the station was built in 1975.