Commercial nuclear power plants in the US would get a $6bn lifeline under the bipartisan infrastructure bill moving through Congress and heading for a vote in the US Senate, but Exelon has warned it might not be what is needed to prevent reactor closures.

A programme to evaluate nuclear reactors that are at risk of being shut down and provide them with aid would be created within the US Department of Energy under terms of the $550bn, bipartisan infrastructure package. The bill provides $6bn for a four-year credit programme for nuclear units in independent power markets at risk of closure.

The senators negotiating the package have completed the text, moving the bill closer to being approved. The legislation is on track to be debated this week, although the timetable for action on the measure in the House is uncertain.