I’m about a third of the way into Midnight in Chernobyl, an account of the 1986 nuclear accident. It’s shocking to read about the number of institutional and design errors that led to the event and then about the missteps in reacting to it.
Even before Chernobyl the Soviets had a history of accidents and meltdowns at their reactors. There was even a prior meltdown at one of the Chernobyl reactors you probably didn’t know about due to layers of Soviet secrecy.
The first sign in the west of an accident was when workers reporting to a Swedish nuclear power plant started setting of radiation alarms when entering the facility because they had picked up so much Chernobyl radiation from the landscape.
In contrast to Chernobyl, the Swedish authorities immediately alerted the nearby town and ordered a facility evacuation. The type and amount of radiation made them think it was their plant leaking. They soon new better.