Re: [Vo]:nuclear salt water reactor for propulsion in space
Well Robin, that certainly bursts my thorium bubble. Should have thought of that myself. It's still not a crazy idea. And as you point out, plutonium could be even better. The main problem with the whole concept is that it would really have to be built in space. Testing this out in the atmosphere would be like a continuous Chernobyl. On Tuesday, May 4, 2021, 08:44:45 PM GMT, Robin wrote: In reply to Michael Foster's message of Tue, 4 May 2021 20:14:00 + (UTC): Hi, Thorium isn't fissile by slow neutrons, only by very fast neutrons, and then the reaction cross section is hundreds of times lower. So the very thing that keeps it safe to store would likely also make it unusable. Though it is fertile, the conversion to fissile takes time, that would not be available in a rocket engine. (The half life of Th233 is 22 minutes, and that of Pa233 is 27 days). In a ground based reactor, you just leave the Th233 & Pa233 sitting around until they slowly convert. Of course, you could do the conversion to U233 on the ground first, (or in orbit for that matter), then fuel the rocket with U233, but that is essentially the same thing as using U235.
Re: [Vo]:nuclear salt water reactor for propulsion in space
I wrote: > Ed Storms worked on the conventional fission rockets shown in this video. > I asked him if he thinks this is plausible. > He does not think it is plausible, for reasons too complicated to describe briefly. - Jed
Re: [Vo]:nuclear salt water reactor for propulsion in space
What's crazy about it? It appears to be more promising than anything else for interstellar travel, unless we discover the reactionless drive that many have proposed. But there is no reactionless drive yet. So why not try this? Furthermore, I think there might be a major improvement possible unless I'm missing something. How about using thorium salt water instead of uranium? You could start the engine with the lowest isotope concentration of uranium salt that would start and maintain a reaction. Then when the reaction is well established make the transition to the thorium salt water. In other words, you would have a uranium "pilot light". A large container of thorium salt solution wouldn't need anything to absorb neutrons and would be inherently stable, thereby avoiding the possibility of catastrophic failure. The uranium salt could be kept in far smaller quantities and would only be used to start the reaction. I doubt this engine would ever be built, but it's fun to speculate. On Tuesday, May 4, 2021, 02:47:45 PM GMT, H LV wrote: The Nuclear Salt Water Rocket - Possibly the Craziest Rocket Engine Ever Imagined. https://youtu.be/cvZjhWE-3zM <>
Re: [Vo]:nuclear salt water reactor for propulsion in space
In reply to Robin's message of Wed, 05 May 2021 06:44:38 +1000: Hi, BTW Plutonium might actually make a better fuel than Uranium, because the number of neutrons created per fission event is higher than for Uranium, ensuring that a larger percentage of the fuel gets burnt, which in turn means that less need be carried. It also gets rid of the nasty weapons grade plutonium we have created here on Earth. Regards, Robin van Spaandonk
Re: [Vo]:nuclear salt water reactor for propulsion in space
In reply to Michael Foster's message of Tue, 4 May 2021 20:14:00 + (UTC): Hi, Thorium isn't fissile by slow neutrons, only by very fast neutrons, and then the reaction cross section is hundreds of times lower. So the very thing that keeps it safe to store would likely also make it unusable. Though it is fertile, the conversion to fissile takes time, that would not be available in a rocket engine. (The half life of Th233 is 22 minutes, and that of Pa233 is 27 days). In a ground based reactor, you just leave the Th233 & Pa233 sitting around until they slowly convert. Of course, you could do the conversion to U233 on the ground first, (or in orbit for that matter), then fuel the rocket with U233, but that is essentially the same thing as using U235. > What's crazy about it? It appears to be more promising than anything else for > interstellar travel, unless we discover the reactionless drive that many have > proposed. But there is no reactionless drive yet. So why not try this? > >Furthermore, I think there might be a major improvement possible unless I'm >missing something. How about using thorium salt water instead of uranium? You >could start the engine with the lowest isotope concentration of uranium salt >that would start and maintain a reaction. Then when the reaction is well >established make the transition to the thorium salt water. In other words, you >would have a uranium "pilot light". > >A large container of thorium salt solution wouldn't need anything to absorb >neutrons and would be inherently stable, thereby avoiding the possibility of >catastrophic failure. The uranium salt could be kept in far smaller quantities >and would only be used to start the reaction. > >I doubt this engine would ever be built, but it's fun to speculate. [snip] Regards, Robin van Spaandonk
Re: [Vo]:nuclear salt water reactor for propulsion in space
...and only 2 months to Jupiter. better than 2001. harry On Tue, May 4, 2021 at 4:09 PM H LV wrote: > It was new to me. > Upto 1.5% the speed of light with the latest design. > > harry > > On Tue, May 4, 2021 at 12:08 PM Jed Rothwell > wrote: > >> I like it! >> >> Ed Storms worked on the conventional fission rockets shown in this video. >> I asked him if he thinks this is plausible. >> >> The paper is linked from the video discussion, here: >> >> https://arc.aiaa.org/doi/abs/10.2514/6.1990-2371 >> >>
Re: [Vo]:nuclear salt water reactor for propulsion in space
It was new to me. Upto 1.5% the speed of light with the latest design. harry On Tue, May 4, 2021 at 12:08 PM Jed Rothwell wrote: > I like it! > > Ed Storms worked on the conventional fission rockets shown in this video. > I asked him if he thinks this is plausible. > > The paper is linked from the video discussion, here: > > https://arc.aiaa.org/doi/abs/10.2514/6.1990-2371 > >
Re: [Vo]:nuclear salt water reactor for propulsion in space
I like it! Ed Storms worked on the conventional fission rockets shown in this video. I asked him if he thinks this is plausible. The paper is linked from the video discussion, here: https://arc.aiaa.org/doi/abs/10.2514/6.1990-2371
[Vo]:nuclear salt water reactor for propulsion in space
The Nuclear Salt Water Rocket - Possibly the Craziest Rocket Engine Ever Imagined. https://youtu.be/cvZjhWE-3zM <>
