South Texas 1 reactor up to 77 pct after refuel

NEW YORK Nov 20 (Reuters) - STP Nuclear Operating Co's 1,280-megawatt Unit 1 at the South Texas nuclear power station in Texas ramped up to 77 percent by early Friday from 37 percent early Thursday after exiting a refueling outage, the U.S. Nuclear Regulatory Commission said in a report.

The unit shut by Oct. 1.

During the outage, workers replaced the reactor vessel head in addition to other refueling and maintenance activities.

The unit last shut for refueling from about March 29-April 28, 2008. It is on an 18 month refueling cycle.

The 2,560 MW South Texas station is located in Bay City in Matagorda County about 80 miles (128 km) south of Houston. There are two 1,280 MW units at the station, which entered service in 1988 and 1989.

Unit 2 meanwhile continued to operate at full power.

One MW powers about 500 homes in Texas.

South Texas Project Nuclear Operating Co operates the station for its owners: NRG Energy Inc (NRG.N) (44 percent), the City of San Antonio's CPS Energy (40 percent) and the City of Austin's Austin Energy (16 percent). (Reporting by Scott DiSavino; Editing by Marguerita Choy)