In Chernobyl, they added small pieces of uranium (or something which increases reactivity) on the tips of boron rods which should stop reactor. It was done to increase control of the reactor, as smaller changes in rods’ position will produce larger changes of reactivity. However, it didn’t works well (obviously), when they tried to use these rods to stop near critical reactor: as the rods entered the reactor, they produced a jump of total reactivity, which contributed to its explosion. This is how I remember the story.
TL;DR: The system which increases corrigibility contributed to runaway changes during a nuclear accident.
In Chernobyl, they added small pieces of uranium (or something which increases reactivity) on the tips of boron rods which should stop reactor. It was done to increase control of the reactor, as smaller changes in rods’ position will produce larger changes of reactivity. However, it didn’t works well (obviously), when they tried to use these rods to stop near critical reactor: as the rods entered the reactor, they produced a jump of total reactivity, which contributed to its explosion. This is how I remember the story.
TL;DR: The system which increases corrigibility contributed to runaway changes during a nuclear accident.