Re: Re: Re: Re: starship-design: Pellet track

[KellySt@aol.com]

In a message dated 8/31/97 4:34:24 PM, you wrote:

>KellySt@aol.com wrote:
>>In a message dated 8/27/97 10:37:05 AM, kuo@bit.csc.lsu.edu wrote:
>>>KellySt@aol.com wrote:
>>>>In a message dated 8/23/97 12:37:20 AM, kuo@bit.csc.lsu.edu (Isaac Kuo)
>>>>wrote:
>
>>>>>Actually, a fusion plant only has to compete with fission plants to
>>>>>acheive great profit potential.  The initial and running costs for
>>>>>motive fission plants are so great that they're now restricted to
>>>>>aircraft carriers and nuclear submarines.  The running costs for any
>>>>>practical fusion plant would be much less than fission or conventional,
>>>>>so that just leaves initial cost--including R&D.
>
>>>>Actually the weight of the power plants reduces them to fairly large
craft.
>
>>>Huh?  Nuclear power plants have been operated on _aircraft_
>>>(research into a nuclear powered bomber included actual flights
>>>of a conventionally propelled bomber with a nuclear power plant
>>>operated on board).  They are light and small enough to potentially
>>>be used on smaller ships, but they are expensive.
>
>>Not a power plant with the power to drive an aircraft or ship.  The nuclear
>>airplane research program caried A power plant, but not one that could
power
>>it, much less one that was SHEILDED.  Surface area rules are nasty to small
>>nukes.
>
>The one which they carried did operate, and was deemed sufficient to
>perform research on safety issues as well as generally demonstrating
>the technology.  More powerful small nuclear power plants have since
>been developed (for instance, research into particle bed reactors
>have led to 300/1 thrust/weight ratio solid core rocket engines).

Note none of the above include sheilding.  


>>About the only small nuclear ship was the Savana.  She ran well, but the
>>reactors weight cut into her cargo capacity, and long shorman refused to
>>unload her.  Some ports refused her entry.
>
>Probably the most important small nuclear powered vessel is the USN's
>NR1, the world's smallest nuclear submarine.  Even though it's only
>44.4m long and 336 tons submerged, it is a fully operational nuclear
>powered submarine with a nominal endurance of 210 man-days.  This thing
>is actually used by civilian researchers (with USN crew running the
>boat) for things like searching for the wreckage of Brittanica and
>mapping coral reefs.  I think it was used to search for TWA 800
>wreckage, but I don't recall specifically.
>
>Seeing as civilians are allowed to use her regularly, I'd say she's
>a safe, seaworthy vessel that isn't spraying its crew members with
>deathly radiation.

She also only has enough power for a 4 knot top speed and has to be towed to
her operational areas.


>>>> Legal restrictions complicated their use so the navy does use them on
all
>>>>large ships.
>
>>>Mostly, however, they are expensive.  Otherwise, the USN would find
>>>a way to go all nuclear.  Thanks to the late Admiral Rickover, at
>>>least our submarine fleet is all nuclear.
>
>>Life cycle wise nukes aren't as expensive then conventional plants.  Not
that
>>thats much of an argument for DOD contracts.
>
>Really?  I doubt that.  If nukes were less expensive, we would
>already see at least some civilian nuclear cargo ships--even if
>the cost savings were long term.  --

Covered that above with the Savana.  She sailed fine, but carried less cargo
and had labor problems.

>---The DoD may not be financially
>shrewd, but international corporations tend to be.  As a point
>of fact, there have indeed been many civilian proposals for
>nuclear cargo vessels, nuclear ocean liners, and even nuclear
>oil tanker submarine (to, among other things, shuttle underneath
>the Arctic).  However, none of these proposals have gotten anywhere.
>Large ocean going ships are very fuel efficient, for the payload mass.
>
>>Subs need the air free nature, and Carriers need to stay clear of ports
(and
>>would burn non-nuke fuel at a tremendous rate).
>
>Huh?  Carriers _do_ burn non-nuke fuel at a tremendous rate--the
>majority of carriers in service today are non-nuclear.  How do they
>stay clear of ports in wartime?  The same way as the rest of her
>fleet, by refueling at sea from tankers.
>
>However, nuclear carriers have an edge in that they have a lot more
>space for aviation fuel and munitions, more free deck space, and
>landing on them is a bit easier.  Such a pity they're so expensive.


To my knowlegde all the US big deck carriers went nuclear years ago.  What
ones are you refuring to?