> Same as the most recent fission plants.
How are these 2 things the same?
On one hand, you rely on a good design and execution to achieve an automatic stop. History has shown time and again that there will always be something that goes wrong: from the cracking rods of Chernobyl to the backup power at Fukushima.
On the other, if you don't design and execute perfectly, nothing works, so there is nothing to shut down. This is the definition of "fail safe".
It's like saying both a meteorite and a rocket will reach 500km/h in the atmosphere, but me it's pretty obvious one is much more likely to do so.