Energy From Thorium Discussion Forum

It is currently Oct 20, 2018 10:34 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 156 posts ]  Go to page Previous  1 ... 5, 6, 7, 8, 9, 10, 11  Next
Author Message
PostPosted: Feb 20, 2016 7:43 pm 
Offline

Joined: Apr 23, 2011 8:47 pm
Posts: 104
From http://www.transatomicpower.com/the-science/

Given ---- 86 MW th/m3, Thermal Capacity: 1250 MWth

Therefore Volume = Only 14.53 M3

Assume diameter and height of reactor core is 1 to 2
3.14X1.05X1.05X4.2=14.53
pi=3.14, radius=1.05, height=4.2

So diameter = 2.1M and height = 4.2M for reactor core.

This seems like a very small reactor core for a 1250 MWth reactor.


Top
 Profile  
 
PostPosted: Feb 20, 2016 7:51 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3827
Location: Alabama
I've been told by several very believable sources that the DOE has reviewed the Transatomic design and concluded that it will not function as they claim, i.e., it will not be able to consume the spent nuclear fuel in its entirety, even if the severe concerns with the ZrH2 moderator didn't exist.

I suspected this all along since every nuclear engineering text will tell you that the thermal-neutron fission of plutonium-239 does not produce enough net neutrons to continue the breeding reaction. Hence, the need for fast reactors to consume uranium-238, which is the overwhelming majority of spent nuclear fuel.


Top
 Profile  
 
PostPosted: Feb 24, 2016 9:57 pm 
Offline

Joined: May 05, 2010 1:14 am
Posts: 129
Quote:
the Transatomic design... will not function as they claim, i.e., it will not be able to consume the spent nuclear fuel in its entirety

Their paper gives a graph of actinide composition for the reactor over time, but says '.. For clarity, uranium-238 is
not included in this figure, as it is >95% of the mass of fuel at all times.'
I guess they should have called it the ' Transuranic Waste Annihilating Reactor ', but TWAMSR doesn't have quite the same ring to it.


Top
 Profile  
 
PostPosted: Feb 24, 2016 10:51 pm 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5045
Kirk Sorensen wrote:
I've been told by several very believable sources that the DOE has reviewed the Transatomic design and concluded that it will not function as they claim, i.e., it will not be able to consume the spent nuclear fuel in its entirety, even if the severe concerns with the ZrH2 moderator didn't exist.

I suspected this all along since every nuclear engineering text will tell you that the thermal-neutron fission of plutonium-239 does not produce enough net neutrons to continue the breeding reaction. Hence, the need for fast reactors to consume uranium-238, which is the overwhelming majority of spent nuclear fuel.


Likely true. They are sort of claiming to eat cake and have it with their bi-modal spectrum reactor. Its fast, and its thermal.

They could theoretically do some breeding with TRUs, but it won't be very good due to all that hydrogen that takes the kick out of the fast bonus.

They could theoretically do some burning with >95% U238 in the mix.

They cannot do both at the same time. Either its predominantly fast spectrum and they can marginally breed but not use the spent fuel (>95% U238 claim) OR they have a predominantly thermal spectrum and do very poor burning of the >95% U238 mix, but they can't breed - not even close.

Its mostly hypothetical though, as the materials compatibillity problems alone are rather daunting.


Top
 Profile  
 
PostPosted: Apr 20, 2016 3:58 pm 
Offline

Joined: Dec 14, 2006 1:01 pm
Posts: 379
I identified the moderator cladding issue on the first reading, and I took the "--" as "we're not telling you" rather than "this is unobtainium." E.g. my first guess would be 3-d woven graphite-fiber, sealed with infused copper, which is extremely sturdy, resists the salt and temperature and has a lot of development for motor brushes. (We even discussed this in one of the fora here.) If the copper doesn't work, they might have some plan to structure carbon allotropes to get a ductile, sealed, salt-proof structure with good neutronics.

How the bimodal neutron energies interact with the fuel is an interesting issue, and it depends on a high resolution neutronics model of the core, fuel and moderator, which note, they claim to have performed. Twice. And shown to their advisers, who include MIT nuclear engineering faculty.


Top
 Profile  
 
PostPosted: Apr 24, 2016 6:08 am 
Offline

Joined: Apr 19, 2008 1:06 am
Posts: 2251
With all my reservations about the Transatomic design, I admire the idea of processing the used LWR fuel to concentrate the fissiles to a fissionable fuel. Carbon. suspended in hydrocarbons in a bitumen like consistency may be a longer lating moderator.


Top
 Profile  
 
PostPosted: Apr 25, 2016 5:11 am 
Offline

Joined: Jun 05, 2011 6:59 pm
Posts: 1335
Location: NoOPWA
Kirk Sorensen wrote:
I suspected this all along since every nuclear engineering text will tell you that the thermal-neutron fission of plutonium-239 does not produce enough net neutrons to continue the breeding reaction. Hence, the need for fast reactors to consume uranium-238, which is the overwhelming majority of spent nuclear fuel.
Except that if a thermal reactor can be made to breed with thorium, it can also be made to sustain with thorium and consume the U238 in Lightly Used Fission Fuel (LUFF) with those spare neutrons.

_________________
DRJ : Engineer - NAVSEA : (Retired)


Top
 Profile  
 
PostPosted: Apr 28, 2016 4:12 am 
Offline

Joined: Apr 19, 2008 1:06 am
Posts: 2251
Extract of wikipedia article on MSR.


Quote:
Transatomic TAP Transatomic Power Corp is a new US company partly funded by Founders Fund and aiming to develop a single-fluid MSR using very low-enriched uranium fuel (1.8%) or the entire actinide component of used LWR fuel. The TAP reactor has an efficient zirconium hydride* moderator and a LiF-based fuel salt bearing the UF4 and actinides, hence a very compact core. The secondary coolant is FLiNaK salt (LiF-KF-NaF) to a steam generator. * as used in TRIGA research reactors and TOPAZ and SNAP reactors for space programme. Owing to the ZrH moderator, there are significantly more neutrons in the thermal region (less than 1 eV) compared with a graphite moderator, thereby enabling the reactor to generate power from very low-enriched uranium or used LWR fuel. The epithermal (1 eV - 1 MeV) spectrum is lower than that with graphite, but in the fast spectrum (over 1 MeV) the neutron flux is greater than with graphite moderator, and therefore contributes strongly to actinide burning. It would give up to 96% actinide burn-up. Fission products are mostly removed batch-wise and fresh fuel added. In addition to negative void and thermal coefficients, the moderator starts to fail at higher temperatures due to hydrogen loss. Decay heat removal can be by convection. After a 20 MWt demonstration reactor, the envisaged first commercial plant will be 1250 MWt/550 MWe running at 44% thermal efficiency with 650°C in primary loop, using steam cycle. The overnight cost for an nth-of-a-kind 550 MWe plant, including lithium-7 inventory and on-line fission product removal and storage, is estimated at $2 billion with a three-year construction schedule. A version of the reactor may utilize thorium fuel.

A thermal uranium fueled reactor, even an MSR, will not be a breeder. It may, however, have a higher conversion ratio and burn more fertile with the same fissile. It could cosume some used fuel till fast MSR is developed and introduced.
A blanket could help things further.


Top
 Profile  
 
PostPosted: Jul 03, 2016 7:01 pm 
Offline

Joined: Jun 05, 2011 6:59 pm
Posts: 1335
Location: NoOPWA
But a 2.2+ fluid Liquid Fluoride Thorium Reactor (LFTR) could use thorium to assure that uranium is completely consumed in a thermal spectrum reactor.

_________________
DRJ : Engineer - NAVSEA : (Retired)


Top
 Profile  
 
PostPosted: Jul 04, 2016 9:32 am 
Offline

Joined: Apr 19, 2008 1:06 am
Posts: 2251
A thermal spectrum LFTR could not produce spare neutrons to be a uranium or even TRU incinerator.
A fast spectrum Th-U233 reactor could.


Top
 Profile  
 
PostPosted: Jul 04, 2016 12:15 pm 
Offline

Joined: Jun 19, 2013 11:49 am
Posts: 1553
If you are going fast spectrum there is little reason to go for a thorium cycle.
You can get very very high breeding ratios in a U-Pu cycle fast reactor.


Top
 Profile  
 
PostPosted: Jul 04, 2016 12:52 pm 
Offline
User avatar

Joined: Dec 22, 2015 8:40 pm
Posts: 359
Location: Florida
KitemanSA wrote:
But a 2.2+ fluid Liquid Fluoride Thorium Reactor (LFTR) . . .
What is a "2.2+" fluid system?

_________________
"Those who say it can’t be done are usually interrupted by others doing it."

—James Arthur Baldwin, American novelist, essayist, playwright, poet, and social critic


Top
 Profile  
 
PostPosted: Jul 04, 2016 6:07 pm 
Offline
User avatar

Joined: Nov 30, 2006 3:30 pm
Posts: 3827
Location: Alabama
Who knows. People on here yap and yap but no one wants to do any hard work. Just act like armchair engineers and demand entertainment.


Top
 Profile  
 
PostPosted: Jul 04, 2016 10:10 pm 
Offline
User avatar

Joined: Dec 22, 2015 8:40 pm
Posts: 359
Location: Florida
So the "2.2+" is troll dung. Great. I thought I had missed something important. Nice.

Hard work. Like what you do, Kirk, and you have a huge number of people who are very grateful for your hard work. Praise for your efforts ought not be in the yapping category. Also, Jim Kennedy and John Kutsch are working hard. (I guess John is working for TE.)

I wish I had the KSAs to qualify for being a part of that hard work. I am 100% in favor of the FE goals. I'm not a good candidate for direct work so I have to settle for the indirect work unpaid. I don't care about the pay. I care about the principle. Kirk, you keep the money.

I figure since ionic liquids techniques are an emerging separations science technology, I can focus on that chem-e course ($200 out of my pocket so far). The Chinese research using them for isotopic separation is still not on the radar. That puzzles me. Jim L was kind enough to post the one paper. Jim L, Kurt Sellner, and most here have good manners that should be followed.

Since the TAP white paper states:
2.6.1 REACTOR NEUTRONICS wrote:
"Although Transatomic Power’s approach could potentially be used with thorium, we are initially focused on the uranium cycle."
This is the energy from thorium (fluoride) forum not the energy from uranium and spent U/Pu solid oxide fuel forum. So far this archive shows ThO2 in MOX solid fuel is NOT the way to go as Dr. Weinburg (inventor of the LWR) and his boss, Dr. Seaborg, surmised in the 1950s or earlier. They were correct then and their view stands the test of time. Time. Time is money. Time for the nuclear industry to show some respect for Dr. Weinburg's judgement--fluid is superior to solid.

TE, TAP, Martingale, who else? Do not agree with the FE goals. All take partial advantage of the fluid phase. But only FE's design takes full advantage of the best salt for fluid-fueled reactors for the best method for utilization of the best fuel for the best direction for the future of nuclear fission energy.

TAP chooses to avoid U-233 because the authorities rule that it is a very serious proliferation risk. Rather than fight that bad rule, TAP abandons thorium at the outset. How brave! No guts, no glory. And presently the highest proliferation risk besides Iran is North Korea. Has Kim Jong Un selected U/Pu or Th/U-233? Any bets? I can do $10 by PayPal.

_________________
"Those who say it can’t be done are usually interrupted by others doing it."

—James Arthur Baldwin, American novelist, essayist, playwright, poet, and social critic


Top
 Profile  
 
PostPosted: Jul 06, 2016 1:11 pm 
Offline

Joined: Jun 12, 2011 2:24 pm
Posts: 92
Location: Taunusstein, Germany
They just updated their white papers:
http://www.transatomicpower.com/wp-cont ... r-v2.0.pdf
http://www.transatomicpower.com/wp-cont ... r-v1.0.pdf


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 156 posts ]  Go to page Previous  1 ... 5, 6, 7, 8, 9, 10, 11  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