I can reply to you with only one thing: please, learn more about modern reactor designs and their safety systems, don't embarrass yourself. Also learn why the Chernobyl event was so nasty and why its impact is significantly bigger compared to Fukushima (hint: graphite moderation).
It's unproductive to discuss such matters with a total layman who didn't bother to do even a basic research, but ok, I will play along.
Let's start from the simplest thing: a Chernobyl-like event is impossible on PWR because they do not use graphite moderators. Simple, right? I could've finished on this, but let me educated you a bit more. Modern reactors have the following safety systems in place (it's not a full list):
- Hydrogen burners (recombiners) mentioned in my previous comment, which significantly reduce amount of hydrogen inside containment.
- Systems for fast automatic Boron injection.
- Heat sink systems designed to work without electricity.
- Passive cooling systems, which are significantly more reliable than the isolation condenser used on Fukushima-1.
- A way of supplying additional coolant externally.
- Core catchers which lead corium from the containment building.
If you know Russian you can read for example this paper [0] from Gidropress (Rosatom subsidiary) to learn more about how modern nuclear reactors handle severe accidents associated with a total loss of electricity. It's about older VVER-1000 reactors, which are a bit less advanced than the newer VVER-1200 and TOI designs, but it should be a good starting point.
> It's unproductive to discuss such matters with a total layman who didn't bother to do even a basic research, but ok, I will play along.
I will play along too. It will be very surprising to me if you are an actual industry insider.
You have not addressed the loss of coolant.
> Let's start from the simplest thing: a Chernobyl-like event is impossible on PWR because they do not use graphite moderators. Simple, right? I could've finished on this, but let me educated you a bit more. Modern reactors have the following safety systems in place (it's not a full list):
Power excursion is very well possible on PWRs during rapid coolant/pressure loss, especially with very fresh, or very old fuel.
Positive scram is possible on PWRs too under condition when rods/poison rapidly reduce coolant temperatures.
Boron injection will not work if your coolant went supercritical.
Catalytic hydrogen recombiners can help with gradual hydrogen release, but would be of no use if you are hit with sudden release.
Passive heat sinks will not do anything if you reactor already lost big part of its coolant. Etc, etc.
