Jan 13 (Reuters) - UK power producer SSE said on Thursday there was no "incident" at its Atwick gas storage facility in northeast England, but that a "fire and gas trip" it reported earlier to the National Grid was prompted by a replacement of the fire and gas detection system.

SSE said the Atwick site, located near Hornsea on the East Yorkshire coast, was expected to be back online by 1800 GMT. (Reporting by Swati Verma in Bengaluru Editing by Susan Fenton and Mark Potter)