V.C. Summer has a history of operating safely, maintaining what he said was an “exemplary’’ record. The recent NRC concern centers on a pipe that delivers fuel to one of the power plant’s two emergency diesel generators, he said. Dominion found problems after testing the piping system, according to the NRC. //

In this case, officials at the V.C. Summer plant learned about cracks in fuel pipes in the facility’s diesel generator system in 2003. Utility workers fixed the initial crack, as well as other cracks four different times in the years after the initial work was done.

But the NRC says the utility never adequately assessed what could be done to make sure the diesel piping system did not experience more cracking. The most recent cracks were identified in November 2022 during a 24-hour test of the system. Workers found a small leak on one of two diesel generator systems. The leak increased over time and workers discovered a 140-degree crack around a pipe, records show.

The cracking occurred mostly in the power plant’s “A” diesel generator system, although one problem occurred in the plant’s “B” generator system. The plant has two backup diesel generators.

The cracking that led to the yellow safety finding follows separate, electrical problems with the plant’s diesel generator system in 2022. The NRC said the company, in that case, also failed to promptly resolve problems, issuing a white finding last year. White is lower in safety significant than yellow, but still considered notable.