US power company Constellation will invest $800m (€751m) in new equipment to increase the output of its Braidwood and Byron nuclear power stations in Illinois by approximately 135 MW, enough to power the equivalent of 100,000 average homes around the clock every year.

The Braidwood and Byron projects involve replacing the main turbines at the two facilities with high efficiency units.

Both stations have two pressurised water reactor units. The two Braidwood units began commercial operation in 1988 and the Byron units in 1985 and 1987. All four plants are Westinghouse four-loop units and have a design ntet capacity of 1,120 MW.

Constellation expects to see increased output at the stations as early as 2026, with the full uprated output available by 2029. Work on the uprates will occur in stages during scheduled refuelling outages.