Which nuclear engine fuel is most worth it?

@Sushiboi
So he's wrong
According to that logic, water would be extremely flammable. It is possible to decompose water into hydrogen and oxygen, but it requires a lot of energy and is quite heavy.
Thermonuclear engines don't work like that. They just heat up the hydrogen, which turns into a gas and, consequently, expands and generates thrust. there is no combustion

@DragoranosSR2 i was referring to what @samthefox said: "water is literally hydrogen and oxygen, making it oxidizer and fuel simultaneously (in my mind)"

@Sushiboi bruh

is pure LH2, without oxidizer
The name of the normal rocket fuel is HYDROLOX (LH2+LOX)

The name of the nuclear fuel is LIQUID HIDROGEN (LH2)

@SamTheFox uh, nuclear engines do not use oxidizers

I think water is better, ngl.

H2O has more density which means its heavier but also means you can pack in more fuel, and since it's literally just regular old water it's hyper cheap
LH2 is expensive and less dense which means you can't pack as much of it in a fuel tank, but makes your craft lighter due to the low density which will definitely make a huge impact

as for efficiency, idk which is best, but generally, if you wanna "save" cash then use H2O, but if you wanna go full weight reduction bro, then use LH2

water is denser, and therefore does not require as much fuel tank volume and hydrogen

and, not only that, but water is literally hydrogen and oxygen, making it oxidizer and fuel simultaneously (in my mind)

Density VS efficiency

Depends for the type of craft that you're using it for