I'm not a nuclear reactor engineer etc, though it was my understanding that control rods in nuclear reactor have always been used to moderate the reaction to co

I'm not a nuclear reactor engineer etc, though it was my understanding that control rods in nuclear reactor have always been used to moderate the reaction to control power output, as well as being a critical safety component. See https://en.m.wikipedia.org/wiki/Control_rod https://en.m.wikipedia.org/wiki/Control_rod