A 1/8 inch sealant injection plug for the Main Generator was discovered out of it's location. This allowed the leakage of
hydrogen gas into the Turbine Building. Fire Brigade leader responded and observed a flammable concentration of
hydrogen. All available ventilation was initiated, and non-essential personnel were evacuated from the 75 foot level of the Turbine Building. Maintenance personnel responded and were able to reinstall the plug.
Hydrogen levels were reduced to less than flammable. No radiological release occurred or is expected.
An Unusual Event was declared at 0908 on 11/10/2003 and terminated at 0908. Unusual Event was declared based on EAL 18a.3 - Release of toxic or flammable gas from anywhere near site or on site that may adversely impact normal station operations.
The licensee notified the NRC Resident Inspector and
New Hampshire.
