The one thing an OFF button should never do is make things worse. But the boron control rods designed to regulate the nuclear reaction in Soviet RNKB reactors had a fatal flow – to save money, they were tipped with graphite rather than boron. Under certain insane conditions, when all water is already removed, this has the effect of briefly mushrooming heat levels, leading to catastrophic failure. But why had the water been removed at Chernobyl? Because a party apparatchik was obsessed with completing a test to earn a commendation. And because some of the plant operators were barely trained.
Technical flaw combined with human hubris combined with penny pinching. Anyway, CHERNOBYL on HBO is now over, but will remain available forever. Everything this graphic says is true. Don’t look for a pro- or anti-nuke docudrama — it’s not that. Just one of the most important true stories of the last century. So good.