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I find various accounts of nuclear accidents fascinating because, as the intro of the article alludes to, they often involve complex systems undergoing complex failure scenarios.

Then there's SL-1 (https://en.wikipedia.org/wiki/SL-1). That was a really stupidly simple failure, but of all the accidents I've read about I find it the most poignant reminder of why nuclear reactors are such complex systems in the first place.

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But it was well documented that you shouldn't lift that one rod above point X. Maybe the message didn't sink into the guy, maybe he screwed up, they even wonder if he committed suicide. Its big message was to eliminate all possible single points of failure, especially ones controlled by fallible humans, even at the cost of increased complexity.

It should be noted that reactivity control in military and commercial PWRs is fundamentally different. That said it's hard to understand how the SL1 operator managed to yank the rod so far out of the core. The procedure was to withdraw each rod 4 inches and attach it to the crdm, which in itself is a little mind blowing to me. The rod was withdrawn 26 inches and prompt criticality was achieved at 23 inches or so. The rod weighed 86 pounds. Even if it was stuck it's hard to imagine yanking something that heavy that far to unstick it.

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