15 Feb (NucNet): The US Nuclear Regulatory Commission (NRC) has issued three violations to the Palisades nuclear power plant, one of which is for a “substantial safety significance” issue related to a September 2011 electrical fault caused by personnel at the site which resulted in a reactor trip.
The NRC said that apart from the reactor trip the incident also led to the loss of half of the control room indicators and activation of safety systems that “were not warranted by actual plant conditions”. This made the reactor trip more challenging for the operators and increased the possibility of a serious event occurring, the NRC said.
The NRC carried out a special inspection and determined the plant failed to have adequate work procedures for the electrical panel maintenance work to ensure the job was done successfully.
The two other violations are for a “low to moderate safety significance” issues. They relate to a coupling failure in the service water system. The system has three motor driven pumps which provide cooling to safety related equipment such as containment air coolers and diesel generators.
In August 2011, one of the service water pumps failed due to cracking in one of the couplings. This was a repeat of a previous equipment failure that occurred in 2009.
The NRC said the violations will result in additional NRC inspections and oversight of the Michigan facility, which is operated by Entergy Nuclear Operations.
The Palisades plant has one 778-megawatt pressurised water reactor unit that began commercial operation in 1971.
