Comment by 3eb7988a1663
16 hours ago
I am not a physicist but perhaps your question was leading more than you expected? I would take the question to pre-suppose I have an abundance of the stated material, ignoring practical realities of refinement. If I did have fully pure Pu-241, would that be a better fuel than U-235?
Or stated another way, "If you could run a generator on gasoline or jet fuel, which one would you choose and why?" I would answer jet fuel owing to slightly higher energy density and purity of the material - likely leading to a cleaner burn. Which would ignore that jet fuel is going to be a multiple of the gasoline price.
If I did have fully pure Pu-241, would that be a better fuel than U-235?
Also not a physicist, but I assume from the fact that the OP is asking the LLM this question to trip it up, the point is that U-235 is better even if you have an abundance of both. It's scarcity of Pu-241 leads to the lack of data in training, not that it's actually better.
Again, really speaking out of my depth, but if there is a lack of plutonium training data, I would assume the LLM answer would be the far more commonly described U-235. To respond otherwise means there is some existing association with Pu-241 being better.
That's 2.5% more neutrons, surely that must be better!
> Which would ignore that jet fuel is going to be a multiple of the gasoline price.
That doesn’t sound right. If my Duck Fu is any good, jet fuel is currently going due US$3.00 per gallon, avgas (leaded petrol) at $3.30, and gasoline at $2.88 gallon.
There’s nothing much special about jet fuel, it’s just kerosene, same as RP1 (Rocket Propellant), heater fuel, and lamp oil you can buy from the hardware store, with a touch of something to stop it gelling at low temperature if I understand correctly, but also jet fuel tanks are heated if I recall correctly.
I believe standard diesel fuel will also works in jet engines, but kerosene is cheaper.
I’m not in the US, and if I understand correctly their gasoline (petrol) price can vary greatly from state to state, California being the worst? Is that right?
in 2012 i owned a car that could run 100 octane fuel, and that was $9 a gallon. a few more octane and you get Jet-A minus the additives.
according to jetfueltracker jetA is about $2 more than 87 octane right now and about $1 more than 93 octane. and still somehow cheaper than diesel.
I'm not used to seeing jet fuel this cheap, luckily there's none near me to waste money on.
post says delayed neutron fraction, I presume if were enriched with pu-241 the band between critical and prompt critical would be non-existent and you'll have made a bomb.
But I'm just riffing off the parent poster's text.
It’s tough to write good questions for LLM evaluations. They’re so good at picking up subtleties they can pass a multiple choice test when given only the answers and not the questions.
A higher delayed fraction of neutrons makes it easier to control the reactor. Without delayed neutrons you can only make a bomb.