Around 07:50 on Easter Sunday morning, an accident at the Arkansas Nuclear Power Plant not only killed one worker and injured others it also left the Unit 1 reactor without offsite power. Workers were using the Unit 1 turbine temporary lift device to move the Main Turbine Generator Stator, which weighs over 500 tons, out of the turbine building when it fell. The lift crane failed, dropping the load, which resulted in a crash which was heard by local residents miles from the site, and tripped the Unit 2 reactor. There was one known fatality and 4 known serious injuries to workers.
The event caused a loss of decay heat removal at Unit 1, which was restored some four minutes later. As the Unit 1 lost all off site power, the Emergency Diesel Generators were started and are supplying backup power.
At 10:33, over two and a half hours later, Unit 2 entered a Notification of Unusual Event due to damage in the 2A1 switchgear. Unit 2 entered hot standby mode with decay heat being removed via steam dumps to the atmosphere.
At this time, the full extent of structural damage on Unit 1 is not known, Unit 2 2A1 switchgear was damaged and currently de-energized, but no other equipment at Unit 2 was reported damaged.
Source: NRC Event Notifications