When I was getting my degree is Physics we had a lab in the "student reactor", which was still in a large building of its own. As part of the lab we got to sit

When I was getting my degree is Physics we had a lab in the "student reactor", which was still in a large building of its own. As part of the lab we got to sit down to the control console of the reactor and control it, on our own. I remember I was turning one knob increasing the power output when suddenly there was a loud noise, everything shook, and the power output went to zero. Turned out it was the failsafe (I think cadmium rods dropped into the core) as I was too agressive with the controls --- it was a normal occurence for students. (All modern reactors are designed in a way that you can't overdrive them, they'll automatically shut down.) It was great fun and a story I'll be telling for the rest of my life.