I never knew that!

[McBeck]

Originally Posted by Gray Lensman

Yes, It was part of Naval Nuclear Power School Training back in the '70s.

The accident was a result of too rapid a change of reactivity when the control rod came unstuck from being "yanked" loose, instantly causing it (the shutdown reactor) to go supercritical, and I emphasize "instantly". Hence the reason for the training was to emphasize NOT to withdraw control rods too fast.

If I'm not mistaken, it's the only nuclear accident (to date) in the U.S. that directly resulted in deaths.

Yes, its a little known fact. Most people remember Three Mile Island.
However, during the Manhatten project, a few people died due to a core and cover of fisile material accidential getting too close during an experiment.
They used a screwdriver to keep them appart and it slipped. (Thats how I remember it and may very well be mistaken). One quickly pushed the materials appart, but depending on how close you were, you got a certain dose. I think they called it "tickling the dragons tail"...

I think its this one: https://en.wikipedia.org/wiki/Louis_Slotin