UPDATE 1-NRC will not order 8 reactors to shut early

(Adds regulatory comment, detail, paragraphs 3, 4, 6-9)

HOUSTON, March 13 (Reuters) - The U.S. Nuclear Regulatory Commission will allow eight reactors to continue to operate until they shut for upcoming spring refueling outages rather than forcing them to shut early to repair potential weld problems, an agency spokesman said on Friday.

The eight reactors, located from New Hampshire to Arizona, will address the weld problems during outages scheduled to begin over the next few weeks.

After an independent review of the latest data from nondestructive tests on pressurizer welds, the NRC staff found nothing that changed its earlier assessment, said NRC spokesman Scott Burnell.

"The plants are going to continue to run until their spring refueling outages," Burnell said.

The agency this week called a special meeting with the eight operators after tests on material removed from a single reactor raised questions about whether the eight units should keep operating until their next scheduled shutdown or be required to perform inspections and repairs sooner on the suspect welds.

The eight plants include Exelon Corp's (EXC.N) 1,152-megawatt Braidwood 2 in Illinois, Luminant's 1,150 MW Comanche Peak 2 in Texas, Arizona Public Service's (PNW.N) 1,314 MW Palo Verde 2 in Arizona, FPL Group Inc's (FPL.N) 1,244 MW Seabrook in New Hampshire, SCANA Corp's (SCG.N) 966 MW Summer in South Carolina, NRG Energy Inc's (NRG.N) 1,280 MW South Texas 1 in Texas, Southern Co's (SO.N) 1,152 MW Vogtle 1 in Georgia and Entergy Corp's (ETR.N) 1,152 MW Waterford 3 in Louisiana.

All of the plants have previously committed to inspect or mitigate these welds during outages to begin over the next six weeks.

Dozens of other reactors using the same technology have either completed action to repair the welds or do not have welds susceptible to these flaws, the NRC said.

The NRC said recent tests of material removed several years ago from a single Florida reactor raised safety concerns about welds on the pressurizer, a vessel that creates and maintains a small amount of steam to keep a pressurized water reactor's coolant system at the proper pressure. (For a factbox on the affected reactors, click on: [ID:nN11382825] ) (Reporting by Eileen O'Grady; Editing by David Gregorio)