IMO, Fukishima is the counter argument to that. Everything worked as designed and they still had a massive accident.
Read the IAEA report, so I'll intersperse some stuff.
Going from memory..
There was an earthquake that knocked out offsite power, so they switched to the backup generators and shut down the reactors. That was how it was supposed to work.
Then there was a flood that knocked out the backup generators. That was unforseen. It wasn't supposed to be possible to have a flood at the same time as an earthquake. OOP's.
Wrong. Tepco (the operator) was advised that the backup generators should be at higher elevation. Decided against it for cost considerations.
A shutdown reactor still generates heat, but they didn't have a way to cool the reactors since they lost all the ways to power the reactor coolant pumps. The reactor coolant overheated and they had a hydrogen explosion with a Loss of Coolant Accident (LOCA). That spread contamination over who knows how many hundreds of square miles. It also uncovered the reactor core.
In part, but operator error in opening the steam release valves allowed the backup coolant to boil off. H2 generated collected in the building and ignited. No containment breach.
In order to cool the core they flooded it with sea water and contaminated some unknown million gallons of sea water.
Some, most was collected. In any event, the additional radionuclide loading in the local seawater was slight.
Everything functioned like it was designed. It just didn't work.
Not really, Those were Gen I GE BWR's , Tepco did not upgrade as recommended by GE. (All US Gen I's have been upgraded)
The real thing to remember from Fukushima is that there were ZERO DEATHS from radiation and NO PROSPECT for future radiation induced diseases. That's straight from the report.
There was considerable debate that the government response was an overreaction and caused deaths by unnecessarily moving people.
ETA - Even in an operating plant, there's radiation leakage. There's some level of radioactive steam that leaks over time from valve stems and pipe seals in the containment building that gets vented to the atmosphere. There's also some leakage between the primary reactor coolant side and secondary steam side from corrosion in the steam generator tubing. Nothing's perfect.
So? Everything on the planet is radioactive. K40 in bananas, Radium in Brazil nuts. The issue is dose. You'd get more of a dose taking a cross country flight than from visiting a power station.
IMO anyway, PWR's aren't really that green.
From a CO2/GWh standard, they are the greenest. By deaths per GWh produced, they're the safest too..
Waste from solar panels and windmills is the issue that everyone seems to ignore. Probably because it's happening in China and not here. Rare earth refining and solar panel production is nasty stuff.
That said, Molten salt is a better bet for grid level power that PWR/BWR's.
