On 11 Mar 2019 at 1:15, Richard Aiken wrote:

> http://www.projectrho.com/public_html/rocket/enginelist.php#id--Nuclea
> r_Thermal--Gas_Core--Open_Cycle--Nuclear_Salt_Water
>
> I am thinking that this would be just the thing for a
> Flash-Gordon-style "atomic rocket ship." Unfortunately, I don't have
> enough math to understand the calculations, so I was hoping someone on
> the list could let me know how to model one of these, in terms of the
> simple Book 1 Classic Traveller shipbuilding rules.

The exhaust will make environmentalists cringe.

> By the way, since the rocket's fuel is stored in discrete
> small-diameter tubes to prevent inadvertent critical mass, battle
> damage would result in [according to the website author] "a nuclear
> explosion inside the ship." But since the fuel only explodes upon
> reaching critical mass, if one were to thread the tubes throughout the
> outer layer of hull and equip each line segment it's own explosive
> reactive armor [to expell and scatter the fuel from the damaged line
> before it could react], you should be able to prevent uncontrolled
> reaction.

Critical mass depends on shape. *Strongly*. Some day I gotta find the
issue of Analog from the early 60s that has a fact aarticle about it
and scan it. I've got it, it's just buried in storage.

In a liquid, density has effects as well. I'd be really worried about
compression waves in that "salt water" setting off a chain reaction.

Just venting the fluid should do. It'll scatter rapidly. Also, as the
water evaporates, that makes it *harder* for a reaction to occur (the
water acts as a moderator, slowing neutrons which increases the
reaction rate.

Leaks inside are a problem because they can form "puddles" whose
shape and volume would cause chain reactions.

Mind you, without some sort of confinement, you won't get a "boom".
at most a "squib" explosion that would scatter the fuel. More like a
quick boil and a radiation flash that could be really bad for
equipment and personnel.

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com