Re: Russia
"The current new kid on the block is the sodium-cooled BN-800 which started up a couple of years ago."
Yeah, because liquid sodium is an intrinsically safe cooling material, even if the loop that happens to get exposed to air doesn't happen to be radioactive, and putting out a fire involving 30 tonnes of sodium that happened to find its way into the basement is easy. (Monju)
There needs to be a checklist of "SHALL NOT" for nuclear reactors and "be able to catch fire" high up on it.
The americans and russians never managed to stop their sodium rigs from catching fire and not to be outdone, the Japanese built Monju. The plant is now being dismantled.
I don't care that "modern technology means it will never leak", the fact that "if it does leak, it WILL burn, it's nearly impossible to put out, and it WILL burn a big hole in the loop causing the rest of the coolant to leak out, giving you an even bigger fire" means that even that "one in a million chance" is one too many.
Lead cooled sounds safe enough but the russians found out the hard way on one submarine that if you let it solidify you can't get to the fuel rods.
If you want to swing your power levels (load follow) then you can't use fuel rods. The Xenon needs to be able to be vented off because apart from the neutron poisoning aspect the sheer pressure of its presence inside the rods breaks the fuel pellets down to a fine powder. That's where MSRs win.
Alvin Weinberg looked at what commerce was doing with his lovely little submarine reactor (powered by uranium because that's what they had available at the time thanks to the weapons program), threw up his hands in horror at the safety issues and came up with an intrinsically safe design. His reward was to be fired and driven out of the industry. Would you run a car using cordite as the fuel?
Biting the hand that feeds IT
