The Nuclear Regulatory Commission (NRC) will renew the operating licence of Entergy's 688MW Pilgrim nuclear power station for the next 20 years in Plymouth, Massachusetts, US.
The current licence was set to expire 8 June, 2012.
Entergy Nuclear president, CEO and chief nuclear officer, John Herron, said the NRC's decision came after it conducted extremely thorough safety and environmental reviews of the nuclear plant.
"The decision ensures Pilgrim's generation of safe, clean, reliable and low-cost energy will continue to benefit the New England area, as will the plant's existing 650 jobs and its $135m in annual economic impact," said Herron.
The plant generates enough electricity to meet nearly 10% of the electrical demand in Massachusetts.
Pilgrim site vice president, Robert Smith, said the NRC spent more than 20,000 hours conducting inspections and reviews.
"At the end of the process, we effectively demonstrated that our systems, structures and components will continue to safely perform their intended function during the 20-year renewal period," said Smith.
The renewed licence enables the plant to operate until 2032, said Entergy, the operator of the plant.
Entergy Corp is an integrated energy company engaged primarily in electric power production and retail distribution operations.
Entergy owns and operates power plants with about 30,000MW of electric generating capacity, and it is the second-largest nuclear power generator in the US.