JENKINSVILLE — Repairs are being made to the V.C. Summer nuclear reactor in Fairfield County after nuclear officials determined that four welds needed repairing on the nuclear plant’s reactor vessel during a scheduled refueling outage for maintenance and repairs.

The penetrations of the Unit I reactor vessel head were identified Oct. 23 and were reported to the U.S. Nuclear Regulatory Commission.

According to Rhonda O’Banion, director of communications with SCANA, the repairs, which began a few weeks ago, are essentially complete now.

Contrary to some media reports, O’Banion said that the repairs to the reactor head were not a threat to public safety.

“The repairs are essentially complete, and V.C. Summer is absolutely safe. This kind of maintenance is not uncommon over the life of a nuclear reactor, and many other utilities have completed such repairs successfully,” O’Banion said. “We look forward to returning the reactor to service safely so that we can continue to provide clean and reliable energy for our customers.”

The plant has been on a scheduled refueling outage this fall, and during that outage routine inspections are done of the reactor, a steel structure six to eight inches thick that contains the facility’s fuel assemblies, to identify potential needs for maintenance and repair.

While assessing the pressurized water reactor, O’Banion said that the “areas we identified for repair were so small they were virtually undetectable with the naked eye.”

Robotic inspection techniques and ultrasonic testing alerted officials to the repair need.

According to a report filed with the NRC, the reactor vessel head has needed no previous repairs for reactor head penetrations or J-Groove welds.

Background information from the NRC about reactor pressure vessel head degradation explains that “the heads of pressurized water reactors (PWR) have penetrations for control drive mechanisms and instrumentation systems. Primary coolant and the operating conditions of PWR plants can cause cracking of these nickel-based alloys and weldments through primary water stress corrosion cracking.”

O’Banion pointed out that these types of repairs have been successfully made on other reactors across the country and explained how these repairs proactively are a part of the station’s commitment to the culture of safety surrounding nuclear power.

More information about nuclear power and safety can be found at www.nrc.gov/reading-rm/doc-collections.