The Nuclear Regulatory Commission has extended the operating licenses of both units at a suburban Philadelphia nuclear plant for an additional 20 years.
The new licenses for the Limerick Generating Station in Montgomery County will now run until October 2044 for Unit One and until June 2049 for Unit Two.
Exelon says the plant generates 2,345 megawatts of electricity, enough power for roughly two million homes.
Donna and Lewis Cuthbert of the Alliance for a Clean Environment, which has fought Limerick's licensing renewal, questioned the need to renew the license when a decade or more remains on the existing license.
The license renewal is the 75th issued by the commission for commercial nuclear power reactors. Another 17 nuclear plant license renewal applications are currently under review.