The Nuclear Regulatory Commission has renewed the operating license of the Peach Bottom nuclear power plant for another 20 years.
The power plant is operated by Exelon Generation Co. and is just across the Pennsylvania border from Cardiff.
Its license approval comes after the plant received high marks for safety in its annual assessment by federal regulators earlier this year.
"They operated in a manner that protected the health and public safety" of the people living near the plant last year, Mohamed Shanbaky, an official with the NRC, told residents attending the plant's annual safety inspection meeting in March.
Shanbaky is branch chief of the NRC's office in King of Prussia, Pa., which has primary responsibility for the annual safety inspection of the Peach Bottom plant.
The NRC's action gives the two reactors at Peach Bottom reactors (Unit No. 2 and Unit No. 3) at least another 30 years of operations.
The original 40-year license to operate the two reactors was not to expire for another 11 years, said Dana Fallano, a spokeswoman for Exelon. The 20 years will be added onto the time left in the original license.
Unit No. 1 came online in 1967 as a test program. It was decommissioned in 1974.
Peach Bottom generates electricity for 2 million customers in the Maryland and Pennsylvania region, according to Fallano.
"This is a significant milestone for us," said the Exelon spokeswoman. "This is our first nuclear site to have its license renewed." The company operates 17 other nuclear power plants nationwide.
Peach Bottom employs 700 workers.
Exelon was formed in October 2000 as a result of the merger of Philadelphia-based Peco Energy and Unicom, which has its headquarters in Chicago. Peach Bottom was formerly operated by Peco.