Energy From Thorium Discussion Forum

It is currently Feb 20, 2018 12:43 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 48 posts ]  Go to page Previous  1, 2, 3, 4  Next
Author Message
PostPosted: Oct 25, 2014 10:32 am 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5057
The Engineer has an article on the "breakthrough".

new-details-on-compact-fusion-reveal-scale-of-challenge

This does not install confidence. They don't even have a shielding design, even though they are going for a concept that has ~10x the fast neutron flux as ITER, where the neutron damage is currently an intractable engineering problem, even with state of the art materials.

Lockheed is really making a big reputation risk here. There is no evidence that they have solved the intractable engineering problems, only evidence to show they haven't actaully gotten to design key systems yet!


Top
 Profile  
 
PostPosted: Oct 25, 2014 10:38 am 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5057
Another quote from the article:

Quote:
Another area where more work is to be done is on the ‘blanket’ component which lines the reactor vessel. This has two functions: it captures the fast neutrons and transfers their energy to a coolant, which McGuire thinks would probably be a liquid metal

Read more: http://www.theengineer.co.uk/news/news- ... z3HAgngwYC


Uh, "probably"???

If someone comes to you and says he's got a new reactor design, and you ask "what coolant" and he answers "it will probably be...

No way! These guys don't even have a pre-pre-preconceptual design yet.


Top
 Profile  
 
PostPosted: Oct 25, 2014 11:31 am 
Offline

Joined: Jul 07, 2010 4:49 pm
Posts: 122
Location: USA
Cyril R wrote:
The Engineer has an article on the "breakthrough".

new-details-on-compact-fusion-reveal-scale-of-challenge

This does not install confidence. They don't even have a shielding design, even though they are going for a concept that has ~10x the fast neutron flux as ITER, where the neutron damage is currently an intractable engineering problem, even with state of the art materials.

Lockheed is really making a big reputation risk here. There is no evidence that they have solved the intractable engineering problems, only evidence to show they haven't actaully gotten to design key systems yet!

____________________________________________________________________________________________________

“There is not the slightest indication that nuclear energy will ever be obtainable. It would mean that the atom would have to be shattered at will.” — Albert Einstein, 1932


Top
 Profile  
 
PostPosted: Oct 25, 2014 11:41 am 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3423
Location: Alabama
In 1932 the neutron had not yet been discovered. That changed everything.


Top
 Profile  
 
PostPosted: Oct 25, 2014 1:24 pm 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5057
Christopher Calder wrote:
Cyril R wrote:
The Engineer has an article on the "breakthrough".

new-details-on-compact-fusion-reveal-scale-of-challenge

This does not install confidence. They don't even have a shielding design, even though they are going for a concept that has ~10x the fast neutron flux as ITER, where the neutron damage is currently an intractable engineering problem, even with state of the art materials.

Lockheed is really making a big reputation risk here. There is no evidence that they have solved the intractable engineering problems, only evidence to show they haven't actaully gotten to design key systems yet!

____________________________________________________________________________________________________

“There is not the slightest indication that nuclear energy will ever be obtainable. It would mean that the atom would have to be shattered at will.” — Albert Einstein, 1932


As Kirk said, it was the discovery of the neutron, that could pass into uranium nuclei, that changed everything. Lockheed is not counting on a new and amazing particle that somehow acts like a neutron and glues together hydrogen nuclei without being bothered by electric repulsion. If they don't have a new and mysterious particle then they are stuck with the same problems. Einstein had a very good point that nuclear energy doesn't work without an electric repulsion bypassing particle "catalyst". Without a catalyst it is down to brute force, namely crazy crazy temperatures, magnetic confinement fields, etc. Apart from that there are other problems such as the inherent instability of plasma (as opposed to the inherent stability of LWRs or MSRs).

In the case of the Lockheed announcement, there does not appear to be any breakthrough, other than perhaps the amount of press coverage Lockheed has gotten on this one. Lockheed is simply looking at an old concept that no one could make to work, and now they claim they can make it work but don't give us even 1 reason why, and the reasons they do give suggest they have exactly nothing (no coolant, no blanket design, no shielding design, etc). It seems Lockheed has simply made a bold announcement and the media have swalled it like sweet rolls.


Top
 Profile  
 
PostPosted: Oct 25, 2014 5:42 pm 
Offline

Joined: Nov 23, 2010 6:51 pm
Posts: 123
^ The "amazing particle that somehow acts like a neutron and glues together hydrogen nuclei without being bothered by electric repulsion" was discovered shortly after the neutron. Unfortunately muon catalyzed fusion is also nowhere near energy breakeven.


Top
 Profile  
 
PostPosted: Oct 25, 2014 5:58 pm 
Offline

Joined: Dec 01, 2006 7:23 pm
Posts: 139
Cyril R wrote:
The Engineer has an article on the "breakthrough".

new-details-on-compact-fusion-reveal-scale-of-challenge


Thank you for the good reference. One can see from the second and third patents that this is a type of mirror machine. One major problem is for fusion to happen, the ions have to collide many times. One collision could send the particles nearly parallel to the field lines and straight out of the machine. Plus it seems that every time a new fusion machine is built, there is another instability discovered. See https://en.wikipedia.org/wiki/Plasma_stability for a list of instabilities.

_________________
Paul Studier


Top
 Profile  
 
PostPosted: Oct 25, 2014 6:30 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3423
Location: Alabama
Titanium48 wrote:
^ The "amazing particle that somehow acts like a neutron and glues together hydrogen nuclei without being bothered by electric repulsion" was discovered shortly after the neutron. Unfortunately muon catalyzed fusion is also nowhere near energy breakeven.


No, muons act like electrons.


Top
 Profile  
 
PostPosted: Oct 25, 2014 6:45 pm 
Offline

Joined: Dec 01, 2006 7:23 pm
Posts: 139
Muons are like electrons but are 207 times heavier. So the nuclei are much closer to each other. Seehttps://en.wikipedia.org/wiki/Muon-catalyzed_fusion

_________________
Paul Studier


Top
 Profile  
 
PostPosted: Oct 25, 2014 6:58 pm 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5057
Titanium48 wrote:
^ The "amazing particle that somehow acts like a neutron and glues together hydrogen nuclei without being bothered by electric repulsion" was discovered shortly after the neutron. Unfortunately muon catalyzed fusion is also nowhere near energy breakeven.


Muons have a charge and moreover are not used in the Lockheed concept.


Top
 Profile  
 
PostPosted: Oct 25, 2014 7:06 pm 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5057
pstudier wrote:
Cyril R wrote:
The Engineer has an article on the "breakthrough".

new-details-on-compact-fusion-reveal-scale-of-challenge


Thank you for the good reference. One can see from the second and third patents that this is a type of mirror machine. One major problem is for fusion to happen, the ions have to collide many times. One collision could send the particles nearly parallel to the field lines and straight out of the machine. Plus it seems that every time a new fusion machine is built, there is another instability discovered. See https://en.wikipedia.org/wiki/Plasma_stability for a list of instabilities.


And even if they manage the plasma instability problem they are still exaggerating other problems. First thing to worry about in terms of materials is the first wall. ITER is already showing this to be an intractable engineering problem even with state of the art materials and technology, billion dollar funding and the best scientists and engineers of our time. Lockheed's concept would increase the neutron flux on the first wall by a factor of perhaps 10. This is the flip side of their high plasma density that Lockheed doesn't mention. Why make an intractable problem ten times worse?

Similarly the neutron flux problem extends downstream all the way to the cryostat, superconductors and electrics, exhaust and intake systems, etc. Which are all also enormous problems for ITER, and ten times worse for Lockheed.

Lockheed's statements on this matter aren't installing any confidence at all. They haven't designed any of this stuff it appears...


Top
 Profile  
 
PostPosted: Oct 25, 2014 8:42 pm 
Offline

Joined: Nov 23, 2010 6:51 pm
Posts: 123
Kirk Sorensen wrote:
No, muons act like electrons.

Cyril R wrote:
Muons have a charge and moreover are not used in the Lockheed concept.

Yes, as negatively charged leptons muons have a lot more in common with electrons than with neutrons, but as a way to initiate nuclear reactions muons are to fusion what neutrons are to fission. The big difference is that fusion reactions do not produce new muons so a self-sustaining chain reaction is impossible. The problem isn't that the fusion catalyst is waiting to be discovered, it is that it doesn't work well enough to be useful.


Top
 Profile  
 
PostPosted: Oct 26, 2014 2:52 am 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5057
Titanium48 wrote:
Kirk Sorensen wrote:
No, muons act like electrons.

Cyril R wrote:
Muons have a charge and moreover are not used in the Lockheed concept.

Yes, as negatively charged leptons muons have a lot more in common with electrons than with neutrons, but as a way to initiate nuclear reactions muons are to fusion what neutrons are to fission. The big difference is that fusion reactions do not produce new muons so a self-sustaining chain reaction is impossible. The problem isn't that the fusion catalyst is waiting to be discovered, it is that it doesn't work well enough to be useful.


It isn't a catalyst if it isn't self sustaining. Neutrons and nuclear fission needed a LOT of coincidences to work at all. The fission needed to produce more than 2 neutrons on average, and it did. There needed to be sponteneous neutron emitters for reactors to be started, and there were. There needed to be delayed neutron emitters in the fission products for reactors to be controllable, and there were. There needed to be materials that strongly absorb neutrons (poisons) to control the reactor, and there were. There needed to be negative feedbacks such as doppler and void to make reactors stable, and there were.

A lot of coincidences that just don't exist with muons in fusion.

But Lockheed, to their credit, doesn't attempt to make muons so this is all off topic and not relevant to the Lockheed system discussion.


Top
 Profile  
 
PostPosted: Oct 26, 2014 11:17 pm 
Offline

Joined: Apr 19, 2008 1:06 am
Posts: 2239
Natural fusion reactors (stars/sun) hold the plasma in a critical condition by gravity, which is large enough. The weapon designers achieved it momentarily by a nuclear fission device. I am not sure what ingenuity it will take to hold it in place for extraction of energy, in spite of Lockheed claims.
In the next decade or two, the priority should be on fission of U-238 and thorium-232 which can meet the world's energy demand for centuries. MSR/LFTR are useful ideas but fast controlled fission of Pu-239 or U-233 should not be given up. It could, in addition to power reactors, be the door to fusion, as in the case of weapons.


Top
 Profile  
 
PostPosted: Oct 27, 2014 2:41 pm 
Offline

Joined: Jun 05, 2011 6:59 pm
Posts: 1330
Location: NoOPWA
Kirk Sorensen wrote:
Titanium48 wrote:
^ The "amazing particle that somehow acts like a neutron and glues together hydrogen nuclei without being bothered by electric repulsion" was discovered shortly after the neutron. Unfortunately muon catalyzed fusion is also nowhere near energy breakeven.


No, muons act like electrons.
Muons make protons act more like neutrons. As it turns out, so might quasi-particles like exciton polaritons or surface plasmon polaritons.

_________________
DRJ : Engineer - NAVSEA : (Retired)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 48 posts ]  Go to page Previous  1, 2, 3, 4  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group