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And there is people freaking out about nuclear reactors...
Posted: Tue Dec 08, 2009 5:44 pm
by Skipjack
http://gizmodo.com/5421617/our-century- ... ion-mapped
Almost 2000 nuclear detonations total 522 of them above ground.
Not really that much health effects in the general world population. considering all that...
I knew it was a lot of tests, never knew it was THAT many though.
Also did not know that there were more testsites in the US than just Nevada.
Posted: Tue Dec 08, 2009 6:56 pm
by AcesHigh
if there was not much fallout, doesnt that mean that we COULD have developed Orion Nuclear Pulse Propulsion spacecrafts?
Posted: Tue Dec 08, 2009 7:09 pm
by Skipjack
Oh I am sure we could have.
I am still convinced that a gas core NERVA RLV would be more reasonable though (though there is people that argue this, but they dont take the theoretical thrust/weight ratio of the newer designs into account).
At least that would be fine, I think.
Posted: Wed Dec 09, 2009 4:40 am
by djolds1
Skipjack wrote:Oh I am sure we could have.
I am still convinced that a gas core NERVA RLV would be more reasonable though (though there is people that argue this, but they dont take the theoretical thrust/weight ratio of the newer designs into account).
At least that would be fine, I think.
DUMBO was the period ('55-'65) NTR-SOLID design with a T/W sufficient for liftoff from the Earth. Current
LANTR NTR-SOLID designs are sufficient for efficient ETO lift, without the potential of fissionable loss in the gas core designs.
Posted: Wed Dec 09, 2009 8:01 am
by Skipjack
Good, did not know that solid core reactors could make it too, or lets say, I always thought it should be possible, but the doubters always argued about the low T/W ratio of solid NERVA engines. So thanks a lot for the links!
If you use a so called "lightbulb" design, then you can make a gas core reactor based engine that does not leak reactor fuel either...
There was a paper on nuclearspace.com (before they had that redesign) that described the design, but I can not find it anymore.
In any case the thing would be huge (though the payload too), which is not necessarily a bad thing.
My gripe with LANTR is that it gives up a lot of the ISP- advantage that nuclear engines have over chemical engines.
Edit, there is an article on nuclearspace.com that brievely mentions the lightbulb design.
http://www.nuclearspace.com/content_scitech2.aspx
Posted: Wed Dec 09, 2009 9:58 am
by kunkmiester
I'd think a solid core engine, being a bit more of a known quantity(we've fired a few of them, IIRC), would be an easier sell.
Posted: Wed Dec 09, 2009 10:30 am
by Giorgio
Skipjack wrote:If you use a so called "lightbulb" design, then you can make a gas core reactor based engine that does not leak reactor fuel either...
Fused Silica is fragile.
While it can be considered for in-space engines, it would be very troublesome to develop for Earth-Orbit-Earth applications.
From my point of view nuclear engines solid core are the best we can have from a power/safety/pubblic acceptance point of view.
Posted: Wed Dec 09, 2009 7:02 pm
by Skipjack
True fused silica is fragile. There are many downsides to this sort of project. This is why I have turned my eyes towards fusion.
The point of my initial post however was that with all the nuclear explosions in the atmosphere, an accident involving a nuclear powered rocket, or any other nuclear reactor is rather insignifficant in comparison.
Posted: Thu Dec 10, 2009 12:20 am
by D Tibbets
Skipjack wrote:True fused silica is fragile. There are many downsides to this sort of project. This is why I have turned my eyes towards fusion.
The point of my initial post however was that with all the nuclear explosions in the atmosphere, an accident involving a nuclear powered rocket, or any other nuclear reactor is rather insignifficant in comparison.
Except for location. If a nuclear reactor ments down it tends to be near more people. Also, a nuclear explosion, tends to distribute its fallout over a large area, dilluting the effect. In a reactor, I assume most of the radiation would stay in the lower atmosphere downwind of the reactor.
In a nuclear rocket people, would worry about where the rocket could fall. I think the designs include robust structures containing the fuel, so there would be little if any spillage beyond the impact crater. But, I believe that also pertained to several radioisotope space probes, and there was hysterical protests over them at launch and subsuquent Earth flybys.
Dan Tibbets
Posted: Thu Dec 10, 2009 2:14 am
by djolds1
Skipjack wrote:Good, did not know that solid core reactors could make it too, or lets say, I always thought it should be possible, but the doubters always argued about the low T/W ratio of solid NERVA engines. So thanks a lot for the links!
My pleasure.
Skipjack wrote:If you use a so called "lightbulb" design, then you can make a gas core reactor based engine that does not leak reactor fuel either...
You lose a lot of the gas core's efficiency advantages vs solid core NTRs by containing the fissionables in the quartz liner.
Skipjack wrote:There was a paper on nuclearspace.com (before they had that redesign) that described the design, but I can not find it anymore.
"Liberty Ship." A BOE notional concept.
Skipjack wrote:In any case the thing would be huge (though the payload too), which is not necessarily a bad thing.
Necessary for serious colonization.
Skipjack wrote:My gripe with LANTR is that it gives up a lot of the ISP- advantage that nuclear engines have over chemical engines.
Still 200-300 seconds better than H2/LOX in LA mode, and with beaucoup thrust. The theoretical Isp range for Liquid Air Cycle Engines.
Posted: Thu Dec 10, 2009 10:15 am
by Skipjack
In a nuclear rocket people, would worry about where the rocket could fall. I think the designs include robust structures containing the fuel, so there would be little if any spillage beyond the impact crater. But, I believe that also pertained to several radioisotope space probes, and there was hysterical protests over them at launch and subsuquent Earth flybys.
hysterical is exactly the words that I would use. As I said, given the nuclear bomb explosions...
Except for location. If a nuclear reactor ments down it tends to be near more people. Also, a nuclear explosion, tends to distribute its fallout over a large area, dilluting the effect.
True, reactors are closer to inhabited areas, though I have always been wondering whether this could not be changed. After all solar power plants are built somewhere in the desert too.
Besides modern nuclear reactor designs are much more safe.
They wont explode.
A nuclear bomb makes a much larger explosion with much more fallout.
The amount of fallout and the area over which the fallout is spread depends on how high above ground the nuclear explosion was. The nearer to the ground, the more fallout and less wide the spread.
Posted: Thu Dec 10, 2009 10:16 am
by Skipjack
Still 200-300 seconds better than H2/LOX in LA mode, and with beaucoup thrust. The theoretical Isp range for Liquid Air Cycle Engines.
Sounds good to me
