The U.S. Nuclear Regulatory Commission has renewed the operating licenses of two reactors at the South Texas Project nuclear power plant for an additional 20 years.

The NRC announced the extension of the licenses for the two pressurized-water reactors on Sept. 28, following a favorable safety evaluation report issued by NRC staff on June 8 and a supplemental environmental impact statement in November 2013. Unit 1's license will now expire on Aug. 20, 2047, while Unit 2's license will now expire on Dec. 15, 2048.

The approximately 2,700-MW nuclear facility in Bay City, Texas, is managed by STP Nuclear Operating Co. and jointly owned by Austin Energy, CPS Energy and NRG Energy Inc. The operator submitted the license renewal application in October 2010.

Most recently, South Texas Project units 1 and 2 made headlines for helping to keep the lights on during Hurricane Harvey despite local mandatory evacuations and flooding.

Plant spokesman Buddy Eller said the license renewal is an important milestone, not only for STP. "There's significant benefits both from an economic and environmental standpoint to having this facility operate until the middle of the century," he said in an interview. "For us it just means jobs in the local communities and it means continued reliable and clean energy for the state of Texas."

In February 2016, the NRC also greenlighted operating licenses for two proposed advanced boiling water reactors at the plant with a nameplate capacity of 1,350 MW each. STP Nuclear Operating's application to build units 3 and 4 was submitted in September 2007, before Nuclear Innovation North America (NINA), a joint venture between NRG and Toshiba Corp., became the lead applicant in 2011. However, in 2011, NRG halted efforts to develop the units under the NINA joint venture.