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PostPosted: Dec 07, 2012 5:51 pm 
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So David, what argument is there for a DMSR if proliferation is taken out of the equation?


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PostPosted: Dec 07, 2012 5:53 pm 
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Kirk Sorensen wrote:
DMSR is a non-solution.

If it's implemented in a weapons-state (US, Russia, UK, France, China) then it's pointless because they would never be running MSRs to make weapons-grade material anyway. You might as well run an efficient LFTR. Pa-sep or no Pa-sep, they'd never be using such a machine to make stuff for bombs.

If it's "given" to some state with nefarious, weapons-lusting motives (and I wouldn't recommend that) then they can stop denaturing it if they wanted to do something illicit.

It solves no problems at all. It was conceived to appeal to Jimmy Carter who was trying to look super-righteous about proliferation. Except Jimmy didn't even mess around with nuclear, just wanted to burn coal instead.

I respectfully disagree in a world where non-proliferation is real issue AND it's easy issue for NIMBY's and nay-sayers to manipulate that issue into scaring people and galvanizing opposition to nuclear power of any kind. If DMSR allows us to tick all the non-proliferation boxes, I think that we should take advantage of that, even if it lacks the desired fuel cycle efficiency than most of us would aspire to.

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If it's "given" to some state with nefarious, weapons-lusting motives (and I wouldn't recommend that) then they can stop denaturing it if they wanted to do something illicit.
Given that DMSR relies on makeup fuel to continue operations, one simply turns of the fuel tap the moment the host country (or reactor operator) defaults on any aspect of compliance and the DMSR will soon go sub-critical leaving the host with an expensive pile of non-functioning equipment. Any attempts to separate fissile material from the core will result in highly degraded, highly radioactive material that would be very difficult to weaponise.

I agree that MSR technology is a poor pathway to nuclear weapons for nation states, but there always seems to be someone somewhere willing to try something on and so it remains appropriate in my opinion to take reasonable steps to protect against diversion of nuclear materials. Choosing to work with unattractive fissile material that is poisoned or degraded seems like a very sensible systematic response to the risk of diversion.

I think that this post highlights quite nicely two different ideologies, option one try to reeducate large numbers of people and change the public perception and regulatory environment surrounding nuclear power while pursuing efficient designs with lower levels of proliferation resistance. Option two, while reeducating people, work within existing regulatory frameworks and generic public concerns regard proliferation and diversion issues and adopt designs that may be less efficient but can demonstrably meet many or all bona-fide proliferation and diversion concerns, including current regulatory limitations.


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PostPosted: Dec 07, 2012 6:08 pm 
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Kirk Sorensen wrote:
So David, what argument is there for a DMSR if proliferation is taken out of the equation?

DMSR w/o proliferation concerns is about the same as MSBR w/o processing. The biggest benefit is reduced R&D effort to get the first one working. Personally, I'd like to include at least a try at noble metal extraction and distillation.

But regardless of real risks, for most places except Russia and China a design that uses HEU will encounter higher political resistance - and if it is clean HEU for a commercial reactor then the political resistance will be much higher.


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PostPosted: Dec 08, 2012 5:01 am 
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Lars wrote:
Kirk Sorensen wrote:
So David, what argument is there for a DMSR if proliferation is taken out of the equation?

DMSR w/o proliferation concerns is about the same as MSBR w/o processing. The biggest benefit is reduced R&D effort to get the first one working. Personally, I'd like to include at least a try at noble metal extraction and distillation.


Noble metal extraction and distillation can't recover the TRUs, so you'll end up losing a lot of your TRUs in the still bottoms. This is another advantage for DMSR. Without considering proliferation, this opens up new options such as starting on TRUs from LWRs and running an otherwise pure thorium fertile cycle. Very good burnout of TRUs can be achieved with the high burnup a once through converter gets, while lots of new U233 will be produced that can start up LFTRs of the online processing type. It looks like a pretty nifty transition plan.


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PostPosted: Dec 08, 2012 7:15 am 
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The real argument for the DMSR is that it is the Do-able Molten Salt Reactor.

A 2 fluid LFTR requires a barrier material that doesnt exist.

A 1 fluid LFTR requires nearly continuous complex processing
of an extremely hot (both ways) fluid. This processing
has not really been demonstrated even at lab scale.

The DMSR needs no new technology.
It's just a scaled up MSRE.
We could build it tomorrow.

And its the obvious first step toward a thorium breeder.

Jack


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PostPosted: Dec 08, 2012 7:22 am 
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Kirk Sorensen wrote:
So David, what argument is there for a DMSR if proliferation is taken out of the equation?

'D' in the DMSR may be out of concern to proliferation worries but it brings into focus an interesting possibility. Enriched LEU or U-Pu239 nodes could provide neutrons to start a thorium fueled reactor with U-233 taking over the function of fissile part later. One of the two could be in solid phase to avoid mixing (Denaturing) to enable separation of U-233 for a purely thorium fueled reactor later.
The main development will continue to take place in Russia and Asia while the Europe, Japan and N America get their second wind.


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PostPosted: Dec 10, 2012 11:47 am 
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Kirk Sorensen wrote:
So David, what argument is there for a DMSR if proliferation is taken out of the equation?



Surprised you'd have to ask. Others have already responded and summed it up nicely. That beyond the added proliferation resistance benefits, the DMSR in general offers a far simpler route to a practical molten salt reactor that can retain virtually all the advantages of a breeder version (resource sustainability, long lived waste profile and certainly overall and fuel cycle costs). This simplicity over breeder options is most evident in the issues of needed R&D and uncertainty regarding fuel salt processing methods and for barrier materials needed for Two Fluid (or 1 and a half ) options. As well I think removing those issues from the conversation with regulators will simplify the path forward.


David LeBlanc


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