Energy From Thorium Discussion Forum

It is currently Jun 19, 2018 7:38 am

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 8 posts ] 
Author Message
PostPosted: Feb 11, 2014 10:55 pm 
Offline

Joined: Dec 13, 2011 9:57 pm
Posts: 33
I have an idea for a graphite core in where the fuel (40UF4-60LiF) and coolant (63LiF-30.5BeF2-6.5ThF4) runs in parallel channels through a machined graphite core.

Metalic gaskets can be developed to joint by continuous compression force the different stages of the reactor structure (core, reflectors, absorbers, manifold and thermal isolator layers) in a pancake structure.

Small quantities of fuel are continuously cycled to remove gas and moble metals.

Protactinium is separated from coolant.

What could be the limiting factors on this concept?


Top
 Profile  
 
PostPosted: Feb 12, 2014 7:16 am 
Offline
User avatar

Joined: Nov 14, 2013 10:31 pm
Posts: 27
Location: Amsterdam, the Netherlands
Quote:
What could be the limiting factors on this concept?


Your wallet, mainly.


Top
 Profile  
 
PostPosted: Feb 12, 2014 12:06 pm 
Offline

Joined: Oct 28, 2013 12:24 am
Posts: 258
I am not an expert but perhaps you may have challenges with 2 things :

- avoiding positive void with your coolant salt
- transfering heat from the fuel salt to your coolant salt (but with tube within tube or other close configuration it may be easy but you need a barrier which resists to the neutron flux and doesn't eat too much neutrons)


Top
 Profile  
 
PostPosted: Feb 12, 2014 12:39 pm 
Offline

Joined: Jul 28, 2008 10:44 pm
Posts: 3066
This is pretty close to ORNL's initial breeder design. They found the challenge of the plumbing and sealing it as the graphite changes dimensions from neutron flux to be too hard. They shifted to a single fluid reactor with very impressive chemical processing plans to achieve much of the same goals.


Top
 Profile  
 
PostPosted: Feb 12, 2014 8:28 pm 
Offline

Joined: Dec 13, 2011 9:57 pm
Posts: 33
It looks that the heat transfer of the core and the plumbing problem can be big issues on this concept.

The reason for the monolitic core structure design, with metal gaskets and preloaded are for three reasons, the first is to address the issue of the graphite change of dimensions with the neutron flux with a constant preload, the second is to investigate if the stressed graphite change its stucture to a metastable diamond configuration with time and thus providing a more sound elemental cubic structure, and third is that the disassembly of the reactor can be performed in an automated way. This concept has to be proven experimentally.
This is a reference about graphite:
https://web.up.ac.za/sitefiles/file/44/ ... acture.pdf

Somebody know where to find a reference literature for how much power per liter of fuel a molten salt reactor produce?

Included are two netron velocity spectrum graphs showing the fuel and coolant neutronic characteristics. It looks like an excellent neutron economy can be obtained from this reactor configuration.


Attachments:
File comment: A fraction of the neutrons will be leaked out of the fuel before being absorbed by the fuel.
N Graph FisionU235-Li7-F-U238-U235 II.jpg
N Graph FisionU235-Li7-F-U238-U235 II.jpg [ 121.52 KiB | Viewed 3871 times ]
File comment: The resonance spectrum of Thorium can be used to maximise neutron absorption.
N Graph C-Li-F-Th II.jpg
N Graph C-Li-F-Th II.jpg [ 97.38 KiB | Viewed 3871 times ]
Top
 Profile  
 
PostPosted: Feb 14, 2014 7:16 pm 
Offline

Joined: Dec 13, 2011 9:57 pm
Posts: 33
There is a positive reactivity isuue on this concept. The concept reactor will rely on emergency stop bars that fall into the reactor core by gravity in case of power loss.


Top
 Profile  
 
PostPosted: May 20, 2014 7:18 am 
Offline

Joined: Dec 13, 2011 9:57 pm
Posts: 33
Related to graphite propierties there is a good document to read about it:
http://zb0035.zb.kfa-juelich.de/record/ ... 3_Haag.pdf
This document relates the effect of isotropy with irradiation stability and crack propagation.
Some authors suggest that high temperature conditions helps to release stresses produced by void on graphite
It will be interesting how a beta type isotropic graphite behaves into a continuously loaded and high temperature conditions under neutron irradiation.


Top
 Profile  
 
PostPosted: May 30, 2014 4:09 pm 
Offline

Joined: Dec 13, 2011 9:57 pm
Posts: 33
I find this document on the internet related to propierties of graphite:
http://web.ornl.gov/sci/physical_scienc ... _Young.pdf


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

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