US utility Constellation has announced it will invest USD800 million in new equipment to increase the output of its Braidwood and Byron nuclear power plants in Illinois by some 135 MWe. They were among the Illinois nuclear plants saved from premature retirement by passage of the state Climate and Equitable Jobs Act in 2021.

The Braidwood (left) and Byron (right) plants (Image: Constellation)

The Braidwood and Byron projects involve replacing the main turbines at the two facilities with state-of-the-art, high efficiency units. The work on the uprates will be carried out in stages during scheduled refueling outages. Constellation expects to see increased output at the plants as early as 2026, with the full uprated output available by 2029.

Constellation said the additional 135 MWe of clean power output is "enough to power the equivalent of 100,000 average homes around the clock every year" and "the equivalent of removing 171,000 gas-powered vehicles from the road per year, or the equivalent of adding 216 intermittent wind turbines to the grid, using Environmental Protection Agency data".

The company said the project is expected "to create work for thousands of skilled union workers during construction while expanding economic activity for surrounding businesses in the plant communities. The additional jobs come on top of the 1200 permanent workers at the two plants".

"These investments in our world class nuclear fleet will allow us to generate more zero-carbon energy with the same amount of fuel and land, and that's a win for the economy, the environment and Illinois families and businesses who rely on our clean energy," said Constellation President and CEO Joe Dominguez. "These projects will help create family-sustaining jobs and are a direct result of state and federal policies that recognise the incredible value of nuclear energy in addressing the climate crisis while keeping our grid secure and reliable."

Since the passage of Illinois' Climate and Equitable Jobs Act in 2021, Congress passed the Inflation Reduction Act (IRA) last year, which provides a base level of support for nuclear energy nationwide. Both pieces of legislation have enabled renewed investment in nuclear energy, Constellation said.

"Support for nuclear in the IRA has made extending the lives of US nuclear assets to 80 years more likely assuming continued support," it said. "It has caused Constellation to examine nuclear uprate opportunities that were cancelled a decade ago due to market forces. The 45Y tax credit for the production of new carbon-free electricity helps make these investments economic".

Byron's pressurised water reactors (PWRs) began commercial operation in 1985 and 1987, and are currently licensed by the US Nuclear Regulatory Commission to operate until 2044 and 2046, respectively. Braidwood's two PWRs entered commercial operation in July and October 1988, respectively. Unit 1 is licensed until 2046, and unit 2 until 2047.

Last October, Constellation announced it is seeking to extend the operating licences of its Clinton and Dresden nuclear power plants, also in Illinois, by an additional 20 years. If approved by the US Nuclear Regulatory Commission, this would enable Clinton's single boiling water reactor (BWR) to continue operating until 2047 and Dresden's two BWRs until 2049 (unit 2) and 2051 (unit 3).