South Texas 2 nuclear unit enters final repair stage

Thu Apr 5, 2012 3:10pm EDT

HOUSTON, April 5 (Reuters) - Workers at the 1,280-megawatt
Unit 2 at the South Texas Project nuclear station in Texas
installed the refurbished rotor on Wednesday as the unit enters
the final restoration phase before it can restart, a plant
spokesman said Thursday. 	
    After a four-month forced outage, the reactor is expected to
return to service by mid-April, well before the state's peak
electric demand, officials with NRG Energy, which owns the
largest stake in the station, told investors last month. 	
    The final restoration phase includes inspections and
post-maintenance testing before the unit is restarted, the
spokesman said.   	
    STP 2 has been shut since Nov. 29, when the main generator
malfunctioned due to a ground fault that resulted in damage to
rotor and stator coils, South Texas Nuclear Operating Co
officials said previously. 	
    The 200-ton rotor was removed from the main generator and
shipped to the Siemen's Energy Center in Charlotte, North
Carolina, where it was reworked to original design
specifications. 	
    Unit 2's 72 stator coils, weighing 800 to 1,000 pounds each,
 were removed and replaced with coils from a Siemen's facility
in Fort Payne, Alabama.  	
    The main generator hydrogen cooler was also shipped to a New
York vendor where it was disassembled, inspected, re-tubed and
shipped back to the site.	
    The Texas grid agency and regulators are watching the
state's generating supply after a heat wave in 2011 sent
electric demand soaring, straining resources. The grid operator
was forced to curtail power to some industrial customers on
certain days, but avoided rolling outages. 	
    STP 1, also rated at 1,280 MW, was operating at 	
full power Thursday.   	
    For eight consecutive years, the STP reactors have produced
more energy than any other two-unit nuclear facility in the
nation, the company said.	
------------------------------------------------------------   	
   	
PLANT BACKGROUND/TIMELINE             	
STATE:      Texas             	
COUNTY:     Matagorda             	
TOWN:       Bay City, 90 miles (145 km) south of Houston       	
OPERATOR:   STP Nuclear Operating Co             	
OWNERS:     NRG Energy, 44 percent; City of San       	
            Antonio's CPS Energy, 40 percent; City of Austin's 	
            Austin Energy, 16 percent       	
CAPACITY:   2,700 MW             	
UNITS:      1 - 1,280 MW pressurized water reactor           	
            2 - 1,280 MW pressurized water reactor          	
FUEL:       Nuclear             	
DISPATCH:   Baseload      	
                 	
TIMELINE:        	
1976 -      Start of plant construction             	
1988 -      Unit 1 enters commercial operation             	
1989 -      Unit 2 enters commercial operation             	
2007 -      NRG files license application to build two new   	
            Advanced Boiling Water Reactors (ABWR) at the site  	
2010 -      STP files application to renew operating licenses  	
            for units 1 and 2 for an additional 20 years      	
2011 -      NRG ends investment in new reactors after   	
            Fukushima accident; COL process continues   	
2011 -      Regulators approve amended ABWR design   	
2027 -      Unit 1 license to expire unless renewed      	
2028 -      Unit 2 license to expire unless renewed