A small fire occurred at the plant on the morning of February 24, 2006. The fire was confined to the Unit 1 Refueling Water Storage Tank (RWST) heater. Initial attempts to extinguish the fire were unsuccessful, following those attempts a breaker was opened and the heater was allowed to deenergize which extinguished the fire. Units 1 and 2 were operating at 100%, but neither reactor was shut down as a result of the fire. As a result of the fire the plant declared an "unusual event", the least serious of the four categories of emergency declarations by the Nuclear Regulatory Commission.