There were other problems after the tornadoes:

A valve failed, a diesel-driven fire pump failed, the diesel-driven generator for the security station failed, the warning sirens were lost, power to the chemical lab was lost, and an emergency diesel generator keeping cool water flowing to one of three reactors shut down because of voltage fluctuations caused by a fluid leak after a brass fitting broke.

Beware phrases like ‘the equipment worked as designed’ and ‘the plant was safely shut down and cooled down’. From TVA nuclear spokesman Ray Golden:

“I don’t think anywhere we use terms like ‘flawless’ or ‘perfect.’ We did use terms like ‘the equipment worked as designed’ and ‘the plant was safely shut down and cooled down.’”