*** A couple of days in between we had a power switch arcing at a third power plant.***
Probably a cheap FEDERAL PACIFIC brand breaker. Replace with TOSHIBA.
As for what happened at the nuke Plant at Russellville, it appears they were attempting to place the stator on a railroad car in the crane bay and the crane failed.
From the looks of it it was not a standard crane that goes across the turbine floor, but a special mobile crane for extremely heavy loads.
Read a report where they stated power failed to the crane. Obviously a make shift crane might be more affected by loss of power under load then a permanently mounted crane on rails.