The U.S. nuclear oversight agency has cited a nuclear power plant in Alabama for a serious safety violation, saying a failure in the emergency cooling system there could have resulted in a dangerous situation.
The Nuclear Regulatory Commission Tuesday said it had issued a so-called "red finding" citation to the Browns Ferry nuclear plant - only the fifth time the agency has used its most severe ranking in the last 10 years.
At issue is a valve in the system that injects coolant into reactors after they shut down. The valve got stuck when the system was being refueled last October.
Nuclear Regulatory Commission regional administrator Victor McCree said the problem was fixed before the reactor was brought back online. He said the public was never in danger. But he said if the failure had happened during a nuclear emergency, the reactor core could have been damaged.
The Tennessee Valley Authority, which owns the plant, says it may appeal the finding. The company says it takes safety very seriously.
The question of nuclear safety has faced increased scrutiny in recent months, following a crisis in Japan when a power plant was crippled by a devastating earthquake and tsunami in March.
The United States has 104 nuclear reactors.
Some information for this report was provided by AP.