Crews at the Perry nuclear plant alongside Lake Erie northeast of Cleveland detected the leak Monday afternoon and reported it the Nuclear Regulatory Commission and the state.
The plant notification to the NRC said tritium was detected in a groundwater monitoring station near the auxiliary building where the leak occurred. There’s no evidence tritium made it off plant grounds.
Plant operator FirstEnergy said the leak is being repaired and there is no threat to the public.
The NRC said tritium is a weakly radioactive isotope occurring naturally in nuclear plant operations. It can be found in self-luminescent items like wristwatches and aircraft dials.