After the Illinois Senate voted to approve an energy package providing millions of dollars in subsidies for the state’s nuclear power plants, Exelon warned that House lawmakers must finalise the deal in less than two weeks to prevent the permanent shutdown of two units at the Byron station, the first of three Exelon facilities lined up for possible closure.

“To be clear, Byron will run out of fuel and will permanently shut down on September 13 unless legislation is enacted,” said Exelon spokesman Paul Adams.

Exelon’s statement came less than a day after the Senate passed a clean energy package that included $694m in ratepayer subsidies in exchange for a commitment that the company would keep its Byron, Dresden and Braidwood stations operating.