You literally just described most operating nuclear power stations. The GE Mark I reactors had an OPTIONAL system to vent hydrogen from secondary containment, as but one example.

I don't know, a nuclear power plant exploding and raining fallout all over Europe sure does look like a failure of nuclear power, certainly for those who experienced it.

Dam failures have had orders of magnitude more impacts, are we calling hydro power a failure?

Let’s not move the goalpost: I am pretty sure we’re calling a dam failure a dam failure.

Yes, but if people hear about dams they don't even blink but they all lose their minds if they hear about nuclear. There is no goalpost moving here, just comparing risks and nuclear looks pretty good.

rootusrootus says we shouldn't call Chernobyl an example of nuclear failure, but I think we very much should because it was a nuclear power plant that exploded. Now you ask 'what about dams' and I'll happily call failing dams failing dams. We were not comparing risks, that's what you brought in - moving the goalposts quite significantly while doing so.