More likely a Nuclear Power locomotive would resemble the N&W Jawn Henry or a UP Gas Turbine locomotive.
http://www.steamlocomotive.com/turbine/
http://www.steamlocomotive.com/turbine/
my gracious!
I liked the "Pennsylvania Turbine Locomotive" of 1944. The beast apparently could go above 100mph and look grand doing it.
Given a nuclear reactor apparatus small enough to fit within, this could be pretty close in appearance to how a nuke-powered steam locomotive could look:
Unfortunately, the disadvantages of turbines make up for it and then some.
I say this as someone who would love to see modern steam locomotives (though not nuclear-steam ones).
Still, its pretty impressive what they (steam locomotives) can do. Comparing a Big Boy to a normal diesel is stacked in the Big Boy's favor...then again that's sort of like comparing Michael Jordan to Woody Allen's dweeb-characters.
The problem is the downsides get seriously undesirable. Steam locomotives are demanding beasts, which is sadly not addressed by either turbines or nuclear power.
Thanks, I'll take a look!
Incidentally, the idea isn't quite dead yet. The Russians are still talking about building one.
The idea might not be dead but I'd be worried about the passengers. Given the country's history I can already see the posters comparing a potential "Mobile Chernobyl" to any other nuclear accident in history, especially if it happens in a major city like Moscow or St Petersburg. Good luck with any other country allowing it inside their borders. Look at Aeroflot now imaging such management with a *nuclear train*!
That's after a refuel, and includes lots of equipment checks as well as a very cautious startup sequence. In an emergency, you could start most reactors in a few minutes, but you would risk damage from the rapid (hence uneven) heating.