NRC SENDS SPECIAL INSPECTION TEAM TO TMI

A Nuclear Regulatory Commission special inspection team has arrived at the Three Mile Island nuclear power plant to review the circumstances surrounding the separation of a steam generator tube. The plant is located in Middletown, Pa., and is operated by Amergen Energy Company, LLC.

During an in-service inspection of the steam generator tubes at TMI last week as part of the refueling outage, Amergen found that a plugged tube had separated from the tube-sheet and caused wear on several adjoining tubes. During the prior period of operation, there was no indication of a problem. The cause of the separation is still being evaluated.

Steam generators are components that transfer heat from the reactor systems to the power-generating portion of a nuclear power plant. In accordance with NRC requirements, Amergen conducts inspections and tests of the tubes in the plant's two steam generators during plant outages to assess the structural integrity of the tubes. Tubes with flaws or degradation above specified limits are plugged (taken out of service by installing plugs in both ends of the tube) or repaired in another manner.

The four-member NRC team will independently develop an understanding of the separation, and review the company's root cause determinations and corrective actions. The team also will perform an independent risk assessment. NRC inspectors also will ensure appropriate corrective actions are taken before the plant restarts from its refueling outage.

An inspection report will be issued about 45 days from the end of the inspection.

As a separate matter, NRC inspectors are also reviewing Amergen's work to identify and repair small cracks associated with control rod drive mechanisms (CRDM) nozzle penetrations in TMI's reactor vessel head. CRDM leaks have occurred at other B&W plants. That work also will be completed before the unit restarts.

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Last revised Wednesday, June 25, 2003