The US Nuclear Regulatory Commission (NRC) has issued a warning to the single unit VC Summer NPP in South Carolina over a cracked pipeline in the cooling system. The plant has reported a series of similar incidents over the past 20 years. Plant owner Dominion Energy said it is planning to improve the reliability of its back-up system. Small cracks have been found a number of times times in the past two decades in pipes that carry fuel to the emergency generators that provide cooling water if electricity fails. NRC has issued a preliminary "yellow" warning to Dominion Energy.
This is the second most serious category and only seven such warnings have been issued in the US since 2009, The State newspaper reported citing nuclear power expert David Lochbaum who has reviewed NRC records.
A crack first appeared on a diesel fuel pipe in 2003, and similar pipes have had other cracks since then. During a 24-hour test of the system in November 2022, a small diesel fuel leak expanded, NRC records show.
The preliminary yellow warning was issued because of the repeated problems. According to The State, Dominion spokesperson Darryl Huger said in an email that NRC’s ruling is not final and the company will have a chance to explain what happened. Dominion has begun work to put in place a plan to improve the reliability of the back-up system and Huger noted that there were multiple back-up systems in case any component fails. He gave assurances that Dominion will continue to keep NRC updated on future strategy to “further enhance our diesel generators”. Dominion has recently requested to renew the licence for the Westinghouse 3-loop 966 Mwe pressurised water reactor for an additional 40 years.
Virginia-based Dominion took over VC Summer in 2018 from Scana, which launched the plant in 1984. Scana had planned to build two more reactors, but was forced to abandon the project in 2017 in face of serious cost overruns. Work on the two AP1000 reactors at the site stopped in July in the wake of the bankruptcy of plant supplier Westinghouse.
Image: The VC Summer nuclear power plant in Jenkinsville, South Carolina (courtesy of Dominion Energy)