Did you read the section on tolerances, and the temperatures? Do you really think such a thing would be reliable for day to day running on an airplane?

It's not impossible of course, but it's not practical, and it's a waste of money. Use the nuclear power on earth, and save the liquid fuels for the air.

The ramjet lives on, but it's not nuclear powered, and don't they call it the 'scramjet' now?

(from wikipedia on Scramjet)

Actually powering a jet from a reactor is a lot more complicated.

albeit the fact that they the B-36 bombers themselves ______were powered by kerosene_______ despite the availablility of nuclear power since it wasn't intended to be anything more than a proof-of-concept flight

You wrote: "proved beyond the shadow of the doubt that it's both doable and feasible" - and at the same time that they didn't do it.

So how did they prove "beyond the shadow of the doubt" something they didn't even do?

That made so little sense I assumed you didn't realize they didn't power the engines from the reactor.

Edit: maybe you don't realize that carrying the nuclear plant is the easy part (heavy lift vehicles exist after all), powering the engines is the very hard part.

As mentioned elsewhere already, this is commonly referred to as a "ram-jet". The heat in such an engine usually comes from combustion, but any old heat source will do.

And that's NOT a ram-jet. Part of the thrust in a ram jet comes from the liquid fuel suddenly growing much larger as it's vaporized.

Using air directly would mean heating it to thousands of degrees. Then you need a material that can handle such temperatures (which don't exist), and still contain the nuclear fuel. And at those temperatures your fuel is molten.

When you burn liquid fuel - it burns at a thousand degrees or so, but then expands rapidly (and cools), so you don't actually have to contain anything at that temperature.

But if you heat air you do - and that's not easy.

Oh, and the entire point of ram and scram jets, is to provide oxygen without blowing out the flame (which is why it's so hard to do). That doesn't apply here.

Edit: Read this http://en.wikipedia.org/wiki/Nuclear_thermal_rocket and you'll see how hard it is. And they had control of the working fluid, you are proposing plain air.

Nuclear powered ramjets

    Main article: Project Pluto

Honestly, though, a hydrogen powered plane is a more likely and more physically reasonable system. Hydrogen has a very high specific energy, and energy density isn't nearly as important as weight in a plane.