[pfdietz]

> Increasing the heat past a certain threshold reduces the nuclear reactivity. Read up on "passive safety".

The safety arguments for fast reactors are typically that a serious scenario will not occur, for example that fuel won't melt, not that if it does occur the results won't be bad. Do you trust that sort of argument? I don't.

[ttfkam]

Nice straw man you've constructed and burnt down.

Those are NOT the safety arguments used within the industry. For example in a molten salt reactor, the fuel is already melted! If it gets too hot, thermal expansion moves the radioactive isotopes further away from one another, reducing reactivity. If heat increases past a certain point, plugs at the bottom of the tanks will melt, allowing gravity to dump the fuel into multiple separated storage vessels sized to prevent further activity.

You do not know what you're talking about. You've read a bunch of fear mongering, and bought it. Do you really believe the entire industry of nuclear engineers and support staff are just blindly YOLOing their way through their jobs, damn the consequences?

I swear, you sound like the power production equivalent of antivaxers convinced the medical industry is trying to poison all of us.

"Passive safety" doesn't mean "stuff shouldn't go wrong."

https://en.wikipedia.org/wiki/Passive_nuclear_safety

It means "we're actively exploring everything that could go wrong and having the worst case scenarios fail to a safe state without requiring human intervention."

Those two positions couldn't be further apart.

[pfdietz]

So, how exactly do you claim conclusively that molten fuel (in a fast reactor with sold fuel elements) will not flow into a bad configuration? I don't see how one can possibly do that analysis. Teller didn't see how either.

I already said MSRs would be the one kind of fast reactor I could see the analysis work, so thank you for agreeing with me on that.

As a charitable act toward you I will ignore the rest of your comment.

[ttfkam]

> I don't see how one can possibly do that analysis.

Classic argument from ignorance fallacy. Because YOU cannot see how it could be done, no one has ever figured out how it could be done.

[pfdietz]

You didn't answer the question.

All the analyses I've seen for fast reactor safety are about avoiding fuel melting, not what happens if the fuel does melt. The variability in this latter scenario is so great that conclusive analysis ruling out disaster doesn't seem possible. Maybe you could explain the unexpected principle that enables one to do that? Or, lacking that, point me to a paper where such analysis has been performed.