Entergy has shutdown Waterford 3, the nearby nuclear plant near the St. Charles-St. John Parish line for required repairs.
A fix is needed to a weld in a pipeline that's an integral part of the plants emergency shutdown system.
Crews monitoring the weld, indicated it was at the point where technical specifications require repair.
The pipe in question helps the plants slow reaction of atomic fuel if a quick shutdown is called for.
Entergy is not saying how long Waterford 3 will be offline.
Waterford 3 shut down Thursday.
Entergy says the utility has plans to provide all the power needed during the hot summer.
Waterford 3 produces more than 1100 megawatts of electricity, meeting about 10 percent of Louisiana's power needs.