A leaking relief valve caused a low-level emergency declaration at Millstone Power Station in Waterford briefly on Sunday.
The leak was located at 9:52 a.m. and stopped at 9:54 a.m., according to Ken Holt at the Millstone Power Station. The incident was resolved by 11 a.m.
There was no threat to the public and no evacuations were necessary.
The leak didn't leak anywhere outside of the plan, but it was leaking into a tank adjacent to it.
The Nuclear Regulatory Commission said there was no release of radioactivity into the environment.
It met the criteria for the lowest of four levels of emergency classifications because the reactor coolant system leaked at a rate of greater than 25 gallons per minute.
The NRC says the problem was traced to a relief valve on the shutdown cooling system.
The plant was in the process of being shut down for a planned refueling and maintenance outage at the time.
The NRC says the system was isolated.