Klaus Moeller:
>> First, 5% enrichment is good for commercial electric generating stations
>> and the efficiency of 36% is good.
>> However, for any sort of space reactor propulsion, enrichment better go
>> up to near 60% or even higher depending on the fuel. For the most part
>> the extra U-238 is just wasted weight (ok, maybe a little conversion to
>> plutonium but not much (relatively speaking.))
>But you're right in that radioactives can be enriched to a much higher
>degree. But I don't know about the risks in enriching radioactives to a
>much higher degree. How safe is your reactor then ?
Extremely so. US Naval nuclear reactors are enriched rather higher than 60%,
with no problems, and we have a better safety record than civilian reactors
do...
>Handling becomes more dangerous with a higher enrichment rate as you
>get to the critical mass more quickly. "Burning Through" your reactor
>is also easier.
No, actually it isn't. In either case...
>Besides, the power plants should be used for civilian and military
>vessels alike. This might not be very realistic.
>And then there's the question of cost efficiency. How expensive
>would be fuel enriched to 10%, 25%, 50%, or even 75% or 90% ?
Enriched fuel costs more than non-enriched fuel, but then we don't
use breeder reactors to MAKE enriched fuel (in large amounts). And we
don't have fusion reactors to convert U-238 to something fissionable
just by parking the 238 next to the reaction chamber...
>Lastly, highly enriched radioactives (90% or more enrichment) make bomb
>grade material. As Imperial law make clear that nuclear bombs are for
>nobody but the imperial military, I don't think that imperial authorities
>allow highly enriched nuclear material to be carried aroound like
>gasoline.
Of course, they allow people to have fusion reactors, and starships that
can slam a planet a Hell of a lot harder than any nuclear weapon you could
build. Note also that 80% enriched fuel is pretty much useless as a weapon,
but allows you to build a nuclear reactor that is MUCH, MUCH smaller than
what you can build at 5%.
>Perhaps I can include a variety of new fuel types. Like
>Radioactives with 5%, 10%, 25%, 50% and 75% enrichment.
>Enriching radioactives is a very complicated task I've heard and gets
>more complicated the higher the enrichment, so the
>price would increase proportional to the square of the enrichment rate while
>efficiency would only increase linearly as less fuel is needed with
>higher enrichment rate.
No. This is false. Enriching radioactives is only difficult when you are
talking about U-238 and U-235. Breeder reactors do it easily. Fusion
reactors make it so simple that any high-school student could do it.
And frankly, it hasn't been terribly difficult since about the sixties, even
with modern technology...
>This way, spaceships are forced to use fusion rockets when they are going to
>another planet but anti grav would be enough to reach geostationary orbit.
Actually, I expect that in that case, they would use jump-drive to go
between planets. Remember that it is faster to micro-jump to Pluto than
to go in real-space, even with 6G maneuver drives...
>The nice side effect would be the elemination of the reactionless thrusters
>and their physical impossiblities.
Impossibilities? Hmmm... Perhaps you should PROVE their "impossibility"
sometime. Just to prove you can...
Steve Higginbotham