A new nuclear power device

Discuss the technical details of an "open source" community-driven design of a polywell reactor.

Moderators: tonybarry, MSimon

icedragonw1
Posts: 10
Joined: Thu Nov 06, 2008 1:49 am

A new nuclear power device

Post by icedragonw1 »

This is a rather new idea, and those who do not fully understand it please ask me your questions. My scientific itch gets the better of me sometimes.

The theory is that nuclear fission and fusion can be used to help each other, especially in the case of a standard fusor.

I looked how the fusion bomb worked and in reality it uses mostly fission, but how much of the uranium is “burned” in a fusion bomb is much higher than in a standard nuclear weapon.

The reason: the neutrons from the fusing tritium and deuterium causes the many more of the uranium atoms to fission in a nuclear bomb

The application: instead of just using deuterium in the fusor, add uranium ions, and there is plenty of ways to do this, the uranium ions will move towards the center with the deuterium.

The deuterium will fuse with other deuterium and produce neutrons, and as the uranium atoms move through the center where the massive neutron source the chance that the uranium atoms will be hit by a neutron will be almost sure fire.

The ones that don’t get hit the first time will, like the deuterium ions, be thrown back towards the center.

The reason uranium atoms are hit: a great analogy to this is by using a small light in a dark room. The light will represent the intensity of the neutron radiation. Holding it at arms length and the light is quite dull, if you bring it closer and closer to your eye it will appear brighter. Sticking it an inch away from your eye will make the light fill your vision and be extremely bright. So the closer the uranium atoms are the more radiation, and higher chance they will fission.

Since the only thing that will deflect the uranium atoms is coulomb repulsion, they will get within less than a nanometer of the neutron source before being deflected.

The idea could be experimented with today’s technology without much money, it’s just a thought, and if anyone wants to run with it, go ahead, I’m a Dj and really I don’t like thinking about this kind of stuff anymore.

eros
Posts: 31
Joined: Sat Nov 08, 2008 7:53 pm
Location: fi

Re: A new nuclear power device

Post by eros »

icedragonw1 wrote:
The theory is that nuclear fission and fusion can be used to help each other, especially in the case of a standard fusor.
How you handle fission waste products?
How capture fission neutrons energy?
What fission things help fusion?

Ok, on/off neutron source maybe, but fission waste make off situation not totall off..

Fission thecnology is quite easy and well known. Greenpeace like it etc..
I think it is not good idea to mix fusion and fission, because normal people don't understand diffrence and if mix them, both got soon bad reputation.
</ Eerin>

MSimon
Posts: 14331
Joined: Mon Jul 16, 2007 7:37 pm
Location: Rockford, Illinois
Contact:

Post by MSimon »

This concept was well discussed either here or at NASA Spaceflight. The Uranium need not be in the reactor. In fact it might poison the reaction. Better is an external blanket.

I believe I also discussed it on my yahoo group and at IEC Fusion Technology.

Basically you could have a subcritical fission reactor that can be controlled by flicking a switch. The most serious problem is that it would also be an easy way to make Pu.
Engineering is the art of making what you want from what you can get at a profit.

KitemanSA
Posts: 6114
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Post by KitemanSA »

MSimon wrote: Basically you could have a subcritical fission reactor that can be controlled by flicking a switch. The most serious problem is that it would also be an easy way to make Pu.
This is the same basic idea as "Accelerator Driven Systems" (ADS) but the neutrons would be provided by the fusor instead of by spallation that results from accelerator driven proton bombardment of dense materials.

And one way around the Pu problem is to use this technology with a molten salt reactor using Thorium as fuel. Properly driven, Thorium goes in, shortish lived fission products come out, and all actinides remain in the molten salt.

=====

Sorry, I did not mean to sound like I was disagreeing with MSimon, I was just using his statement to bring up an interesting alternative process.

MSimon
Posts: 14331
Joined: Mon Jul 16, 2007 7:37 pm
Location: Rockford, Illinois
Contact:

Post by MSimon »

I love disagreement. It is a way to learn something.

Still if you used Uranium in the blanket you get Pu. And you know there might be people who are not very nice who might want to do that.

The one thing that would help is that you have to reprocess. And that is dangerous and somewhat detectable.
Engineering is the art of making what you want from what you can get at a profit.

icedragonw1
Posts: 10
Joined: Thu Nov 06, 2008 1:49 am

Post by icedragonw1 »

I didn't like the blanket idea, if you throw only small amounts at a time in the fusor directly the uranium will be less than a nanometer from the neutron source, causing almost complete burn the first time around. The small amount of waste will be the fission products that if the fusor shuts down will hit the metal wire or container and would be atoms thin coating glazing. very little actual plutonium would be made that didn't fission afterwards.

icedragonw1
Posts: 10
Joined: Thu Nov 06, 2008 1:49 am

Post by icedragonw1 »

using a deuterium or lead blanket would work well as a way of capturing the energy from the neutrons.
Though it's my lack of knowledge in certain areas of nuclear technology, but I thought that fission produced thermal energy as well as neutrons.

MSimon
Posts: 14331
Joined: Mon Jul 16, 2007 7:37 pm
Location: Rockford, Illinois
Contact:

Post by MSimon »

Well the blanket idea has the positive attribute of making the extraction of heat from the nuclear reaction easier. It also greatly simplifies the design. Plus you don't have to worry about the reactor becoming radioactive from fission products. Nasty stuff that. And then there is the the problem of the vacuum pumps getting radioactive and the problem of radioactive Xenon gas in the exhaust. And all kinds of other radioactive crap condensing in the vacuum system.

Plus ionized Uranium is going to absorb a lot of drive energy. +92 vs +5 for boron or +1 for D or H.

Plus to get reasonable absorption of neutrons by U the neutrons need to be thermalized. That is best done by a water blanket around the reactor.

But I will grant that a study of fission reactors is in order.
Engineering is the art of making what you want from what you can get at a profit.

KitemanSA
Posts: 6114
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Post by KitemanSA »

MSimon wrote:Still if you used Uranium in the blanket you get Pu. And you know there might be people who are not very nice who might want to do that.

The one thing that would help is that you have to reprocess. And that is dangerous and somewhat detectable.
That is the beauty of the Thorium fueled molten salt reactor. The only Uranium is the fissile U233 or U235 that is the actual fuel and it is in VERY small percentages. Per Wikipedia, the molten salt constituents are as follows: "LiF-BeF2-ThF4-UF4 (72-16-12-0.4)". There is NO fertile U238 to breed Plutonium from. Cool, no? And without the neutron enhancement, the reactor won't breed enough U233 to keep itself going, so its not like there will be any to spare for weapons development.

The other great thing is that "reprocessing" is simply the chemical removal of fission products, not the nuclear enrichment reprocessing one usually thinks of. And the Fission products are back to "background" radiation levels in a few hundred years, not the millenia required for actinides.

drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:

Post by drmike »

Do a web search on "hybrid nuclear reactor". Here's an example:
The Fusion-Fission Hybrid Reactor for Energy Production: A Practical Path to Fusion Application

It's a great idea. I don't think it is economical, otherwise somebody would be doing it.

MSimon
Posts: 14331
Joined: Mon Jul 16, 2007 7:37 pm
Location: Rockford, Illinois
Contact:

Post by MSimon »

Kiteman,

I'm not arguing what should be done to generate power.

I'm suggesting what could be done if some one was bloody minded.
Engineering is the art of making what you want from what you can get at a profit.

icedragonw1
Posts: 10
Joined: Thu Nov 06, 2008 1:49 am

Post by icedragonw1 »

well if any of the neutron club want to try a idea similar to this, it's not hard. Using radium is a aqueous solution as a fine mist in the reactor. The radium will quickly be ionized and go towards the center. This would be another experiment to see what happens. the fusion reactor would make some really weird particles and something unexpected might happen.
but it would be a fun experiment for those who have the know how.

KitemanSA
Posts: 6114
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Post by KitemanSA »

MSimon wrote:Kiteman,

I'm not arguing what should be done to generate power.

I'm suggesting what could be done if some one was bloody minded.
I guess I am not getting your point. If someone were bloody-minded, they wouldn't build a Thorium molten salt reactor. If they build a molten salt reactor, they are probably not bloody-minded. There would be MUCH easier ways to get Pu with a fusor than to mate it with a molten salt reactor!

MSimon
Posts: 14331
Joined: Mon Jul 16, 2007 7:37 pm
Location: Rockford, Illinois
Contact:

Post by MSimon »

KitemanSA wrote:
MSimon wrote:Kiteman,

I'm not arguing what should be done to generate power.

I'm suggesting what could be done if some one was bloody minded.
I guess I am not getting your point. If someone were bloody-minded, they wouldn't build a Thorium molten salt reactor. If they build a molten salt reactor, they are probably not bloody-minded. There would be MUCH easier ways to get Pu with a fusor than to mate it with a molten salt reactor!
Well there is my mistake. I wasn't contemplating a molten salt reactor to make Pu. Sorry I didn't make that clear.
Engineering is the art of making what you want from what you can get at a profit.

jmc
Posts: 427
Joined: Fri Aug 31, 2007 9:16 am
Location: Ireland

Post by jmc »

drmike wrote:Do a web search on "hybrid nuclear reactor". Here's an example:
The Fusion-Fission Hybrid Reactor for Energy Production: A Practical Path to Fusion Application

It's a great idea. I don't think it is economical, otherwise somebody would be doing it.
Yes I too have heard of this idea and wonder where its economic niche is The reactor itself is bound to be more expensive that a PWR. The and waste would just as expensive to store away safely.

The one potential advantage I thought a sub critical fusion fission hybrid might have over a run-of-the-mill fission reactor would be the ability to ramp up and down energy production much faster than a PWR, correct me if I'm wrong but I believe for some reason PWR aren't good at ramping power production up and down rapidly, making them only good for baseload.

The confinement time in a fusion-fission-hybrid grade plasma is about 1 or two seconds so it seems reasionable that power output could be made to fluctuate on that timescale, and ofcourse a fusion reaction is controled magnetically which is less cumbersome than lifting and lowering control rods.

I wonder whether a fusion fission hybrid might take the role of the nuclear version of a gas fired power station ramping up and down production with demand.

Post Reply