UPDATE 1-Progress Florida reactor likely shut for months

(Recasts, adds company, regulator comment)

HOUSTON Nov 23 (Reuters) - An outage at Progress Energy's (PGN.N) Crystal River nuclear power station in Florida will likely be extended for "months" as the utility deals with a crack discovered in the wall of the containment building, a nuclear regulatory agency spokesman said on Monday.

The 838-megawatt unit shut Sept. 26 for a refueling outage and work to replace two steam generators. The unit had been expected to return in mid-December.

However, a gap in the concrete wall of the containment building found as workers removed concrete to create an opening to gain access to the generators, will keep the unit offline until the cause of the crack can be determined and repaired.

The unit is likely to be shut "a few months," said Joey Ledford of the U.S. Nuclear Regulatory Commission's Region II office in Atlanta.

Progress spokesman Mike Hughes declined to speculate how long the unit will be shut. "We know the outage will be extended," he said.

The utility is still working with regulators to determine the cause of the crack found in the 42-inch (107-cm) thick wall which contains both horizontal and vertical tensioned steel tendons and a steel-plate lining.

In a meeting with NRC officials on Friday, Progress said testing had shown no other areas of concern, Hughes said.

Progress' officials believe the best repair option will be to remove more of the affected wall and repour the concrete, Hughes said.

Additional work to determine the cause of the problem must be completed before a repair plan is finalized. "We must be fully comfortable with (the root cause analysis) before it is clear what the fix will be," Hughes said.

Crystal Rivers' old steam generators had been removed and other work associated with the outage goes on, Hughes said.

Other equipment is being replaced as part of the first phase of a planned power upgrade that will boost the unit's output by 180 megawatts when completed in 2011.

Ledford said a special inspection launched last month by the NRC will continue for several more weeks.

The 3,151-MW Crystal River station, located in Red Level, Florida, about 85 miles (140-km) north of Tampa, includes four coal units and the nuclear reactor.

Progress Energy operates the reactor and has a 90-percent ownership stake. Minority owners include 10 public power agencies.

Reporting by Eileen O'Grady; Editing by Marguerita Choy) ((eileen.ogrady@thomsonreuters.com; +1 713 210 8522; Reuters Messaging: eileen.ogrady.reuters.com@reuters.net)) ((For help: Click "Contact Us" in your desk top, click here [HELP] or call 1-800-738-8377 for Reuters Products and 1-888-463-3383 for Thomson products; For client training: training.americas@thomsonreuters.com ; +1 646-223-5546))