Crystal River Unit 3 is currently shutdown. Final tendon re-tensioning activities were being conducted following repair of delaminated (separated) concrete at the periphery of the containment wall. At approximately 1311 [EDT] on March 14, 2011, an indication was received from acoustic monitoring instrumentation located on the containment wall outside the previously repaired area. Re-tensioning activities were stopped and Plant Operations verified that there were no changes in plant parameters.
Non-destructive examinations were initiated and preliminary indications are that there is delaminated concrete in the area identified by the acoustic monitoring. An assessment concluded that the containment continues to maintain the closure-pressure retaining capability required for Mode 5. There continues to be no threat to the public heath and safety.
Delaminated concrete at the periphery of the containment wall was created in late 2009 during the process of creating an opening in the structure to remove and replace the steam generators inside (Reference Event Report 45416). The unit was already shut down for refueling and maintenance at the time the damage was found and has remained shut down.
The extent of newly discovered delaminated has not yet been determined.
The licensee plans to make a press release.
The licensee has notified the NRC Resident Inspector and the
Florida Public Service Commission.