The Nuclear Regulatory Commission rejected a request Tuesday from PG&E (NYSE:PCG), the operator of California’s last nuclear power plant, that could have smoothed the way to extend the operating life for its twin reactors.

PG&E (PCG) asked the NRC in October to resume consideration of an application initially submitted in 2009 to extend the life of the Diablo Canyon nuclear plant, which later was withdrawn after the company announced plans in 2016 to shutter the reactors.

Fearing possible energy blackouts, Governor Gavin Newsom and the California legislature canceled the 2016 agreement to close the plant and opened the way for PG&E (PCG) to seek a longer operating run from federal regulators.

But on Tuesday, NRC staff refused to go back in time to resume consideration of the previous license extension plan, saying “it would not be effective or efficient” to start the review without updated information on the plant’s condition.

After the rejection, PG&E (PCG) said it will submit a new application to renew its license for 20 years – the typical term – by the end of this year.

The U.S. Department of Energy said in November it would give a $1.1B grant to help PG&E keep the Diablo Canyon plant running.