Congratulations to David LeBlanc (ORNL)

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jaro
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Re: Congratulations to David LeBlanc (ORNL)

Post by jaro » Sep 16, 2016 3:46 pm

Kirk Sorensen wrote:I have been wondering about a purely LEU-fueled MSR for at least ten years now, but I must admit, I have not given it a great deal of thought until recently.
That's excellent news.
At long last, Flibe may be able to compete in the civilian sector, where LEU is a precondition.

There is no shame in abandoning a politically non-viable mantra.

Or even an old concept: For example DL dropped his famous "tube-in-tube" reactor idea, even after applying for a patent, and after a series of promotional presentations in both the US and Canada.

Terrestrial Energy is now developing a much more conventional-style MSR, that replaces a hopelessly unstable configuration derived from a misunderstanding of the applicability of elementary single-point reactor physics to the real world of 3D neutronics (Yes, even faulty concepts can be patented!).

I say that's great ! "Live and learn"

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Tim Meyer
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Re: Congratulations to David LeBlanc (ORNL)

Post by Tim Meyer » Sep 16, 2016 4:44 pm

TerjeP wrote:I'm not a US taxpayer. But I would feel much the same way as Kirk does if I was. The US government already has a tonne of debt . . .
I am a US taxpayer and a voting US citizen. Why do people love to talk about debt without mentioning assets? US assets make the debt look like chump change. How about 1,200 F-35 JSFs for the USAF? That's over a trillion dollars for one defense contractor. One. Guess who. China hacked their system and stole their blueprints, I heard.

This is about US national priorities one of which can become to show the world how to operate on emission-free thorium in the right way. If US leadership prompted by The People want this done, it would get done. For example, Churchill wanted FDR to help. France, too. And Japan wanted to keep going. Now we all have to deal with nuclear technologies and their risks to everyone—a lot of opinions from every direction.
jaro wrote:. . . a hopelessly unstable configuration derived from a misunderstanding of the applicability of elementary single-point reactor physics to the real world of 3D neutronics . . .
Explain, please. Thank you. Jaro, are you Canadian?

Thank you for correcting me, Kirk. Apologize. And if the US nuclear laws allow for your licensing plan, your first site will require public hearings. And licensing, operating, and other fees. But all the R&D comes out of your pocket. Lockheed Martin decided against the thorium MSR. Looks like they're doing well with the Joint Strike Fighter for war—excuse, defense. So. "Crap" was what I was wondering but not qualified to judge. Evidently, Jaro has secret answers beyond the understanding of non-nuclear engineers.

Interesting: you started this forum in the afternoon of November 30, 2006 almost ten years ago, and have at this moment 2882 posts. Jaro joined later that evening and since has accumulated 1949 posts up to now. David LeBlanc joined in March 2007 and has 917 posts. If there is a nuclear engineering prerequisite to participate here, then I'm disqualified. Nuclear reactor sites have public hearings by law probably because privately using radioactive materials for energy production for profit has wide consequences for the nature of these materials and the product. There is a private password-protected section of this forum. Yet this discussion is out in the open.
"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

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Kirk Sorensen
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Re: Congratulations to David LeBlanc (ORNL)

Post by Kirk Sorensen » Sep 16, 2016 4:49 pm

jaro wrote:At long last, Flibe may be able to compete in the civilian sector, where LEU is a precondition.
Sorry to disappoint you Jaro, but we're still working on the U233-fueled LFTR. We listen to what physics tells us here at Flibe Energy, not to what the politicians who can't integrate a constant say.

What I'm saying is that I strongly suspect an LEU-fueled MSR can't outperform a CANDU, or maybe even an LWR.

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Kirk Sorensen
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Re: Congratulations to David LeBlanc (ORNL)

Post by Kirk Sorensen » Sep 16, 2016 4:51 pm

Tim Meyer wrote:And licensing, operating, and other fees. But all the R&D comes out of your pocket.
Yeah, we knew this before we ever started.
Tim Meyer wrote:Lockheed Martin decided against the thorium MSR.
What on earth are you talking about? Are you just inventing things?
Tim Meyer wrote:Interesting: you started this forum in the afternoon of November 30, 2006 almost ten years ago
Yeah, and at the rate it's going I might wrap it up on November 30, 2016. It sure hasn't turned out to be much.

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Tim Meyer
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Re: Congratulations to David LeBlanc (ORNL)

Post by Tim Meyer » Sep 16, 2016 6:05 pm

The comment about Lockheed Martin, Kirk, is that for US national defense, our nation spends a lot—hundreds of billions—of taxpayer money for fighter jets and a lot more. If the US wanted a thorium MSR for, say, national defense, you get the point. Union Carbide and others had the contracts at ORNL during the MSBR, yes? I didn't mean anything idiotic from my comment but I assumed the reason there hasn't been news about LFTR progress is because of insufficient funding that is private information. I apologize.

And your closing this forum down on November 30, 2016, is as good a time as any. Would it remain searchable or would it be available for sale or how would that work? Deleted? You're saying this collection of posts "hasn't turned out to be much" but not from my viewpoint and others might agree. If it goes away, I learned a lot about this issue of energy from thorium on your forum. Thanks for allowing me to engage you and a few folks here.

I never had the talent to do the engineering. But the goal of Flibe Energy seems to be really important not just for our nation but for the world. Unless there is an impenetrable technical barrier to your LFTR working. And I hope it isn't true. If I live long enough to see it working, that will be a happy day for me. Meantime, I'm going to continue to follow the science as much as I can and tell people about it. Politicians have the power to appropriate funds to pay for big energy projects. People vote for our representatives and we can focus on ones that support thorium MSR technology.

Thank you, Kirk.
"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

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jaro
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Re: Congratulations to David LeBlanc (ORNL)

Post by jaro » Sep 16, 2016 6:21 pm

Tim Meyer wrote:Explain, please. Thank you. Jaro, are you Canadian?
Yes indeed. Canadian, just like DL.
The problem with the "tube-in-tube" idea was a very high aspect ratio -- about 8 : 1 as I recall -- which is fine in elementary point reactor theory, but says nothing about the real world.
In the real world, that thing would oscillate like crazy, causing vibrations that would shred it to pieces in a day or two.
Tim Meyer wrote:Evidently, Jaro has secret answers beyond the understanding of non-nuclear engineers.
No secret answers.
But there is a real problem with analyzing and evaluating configurations with extreme geometry.
Generally people don't bother doing it, because it's a dead end: Nothing practical is likely to ever come out of it.

By the way Tim, don't put much faith in those posting statistics: There has been much trimming of old posts, so current numbers are a fraction of actual numbers.

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BSFusion
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Re: Congratulations to David LeBlanc (ORNL)

Post by BSFusion » Sep 16, 2016 11:53 pm

jaro wrote:The problem with the "tube-in-tube" idea was a very high aspect ratio -- about 8 : 1 as I recall -- which is fine in elementary point reactor theory, but says nothing about the real world. In the real world, that thing would oscillate like crazy, causing vibrations that would shred it to pieces in a day or two.
I want to know more about this oscillation problem. Where should I look?

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TerjeP
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Re: Congratulations to David LeBlanc (ORNL)

Post by TerjeP » Sep 17, 2016 12:12 am

What I'm saying is that I strongly suspect an LEU-fueled MSR can't outperform a CANDU, or maybe even an LWR.
If that is true then it suggests Terrestrial Energy have seriously miscalculated. They claim it will use 1/6 the fuel of a LWR.

But even if they used the same amount of fuel as a LWR they would still likely be a worthy improvement. On paper at least the IMSR looks much cheaper to build and safer to operate compared to a LWR like the AP1000. And fuel recycling for an MSR should be simpler.

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jaro
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Re: Congratulations to David LeBlanc (ORNL)

Post by jaro » Sep 17, 2016 8:00 am

BSFusion wrote:I want to know more about this oscillation problem. Where should I look?
The problem arises even with large, ordinary reactors, where the total amount of "lattice units" (fuel + moderator) is many times the minimum for criticality.
But it is much less severe and readily managed, because the solid fuel is segregated from the moderator, which tends to dampen combined flux-thermohydraulic effects -- in contrast to MSRs, where things may be more intimately mixed (especially types without graphite or other solid moderator, or external moderation only).
Also, the risk is magnified with extreme aspect ratio -- both because the total amount of fuel salt is well above minimum for criticality (as compared to low aspect ratio cylinder or sphere), and because such configurations provide a nice resonance chamber for oscillation (think of an organ pipe and acoustic oscillations).
Another way to magnify the risk is by increasing compressibility of the fluid, for example with the presence of bubbles of fission product gases and vapors like Krypton, Xenon and Tritium, as well as Helium introduced on purpose to scavenge the FP gases.
The most extreme case would of course be a gaseous or vapor core reactor with extreme aspect ratio: In the 1950's there was in fact a concept for a strongly oscillating reactor that would extract electric energy by magneto-hydrodynamic means, as a shockwave passed several times per second from one end to the other, while interacting with coils wrapped around the cylinder.
The oscillation was of course driven by compression and fission power bursts at each end of the long cylinder, as the shockwave hit the end wall.

In commercial nuclear power, issues like neutron flux oscillations are generally handled by teams of reactor physics analysts working for the Company that designs and builds the plants.
So most of it is proprietary IP.
Not sure if you could find any textbooks or graduate-level courses that deal with the matter.

On a simpler level, there is much publicly available material on the subject of power-driven acoustic oscillation in fossil fuel burning furnaces, and also in rocket engines (rocket engines designed without careful attention to acoustic oscillation will explode within seconds of ignition...).

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Re: Congratulations to David LeBlanc (ORNL)

Post by E Ireland » Sep 17, 2016 1:04 pm

Im tempted to determine if a SEU fueled load under power reactor cooled with boiling light water and moderated with heavy water would achieve decent economics. Load under power is much more developd than it was when they attempted Gentilly 1 thanks to endless Magnox/ AGR and CANDU experience.

Kurt Sellner
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Re: Congratulations to David LeBlanc (ORNL)

Post by Kurt Sellner » Sep 18, 2016 7:35 pm

Kirk Sorensen wrote:The reason all these companies don't "get together" is because they all see the go-forward strategy differently. That's ok. But that's why they don't "join forces" and that's why there are so many disparate concepts.
I would not want all these companies to join forces either. LFTR, IMSR, and WAMSR all solve different problems. Or, perhaps, they all solve the same problem of energy production but with different compromises. I can see a future where all of these technologies, and more, coexist because different parts of the world have different compromises to make.

I like Dr. LeBlanc's IMSR as it solves a problem of providing energy to remote locations in a way that has low risk of weapon proliferation and environmental impact. In this case a loss of performance over more complex LWRs may be acceptable. Even if used in a large power plant closer to "civilization" this may be acceptable because of the inherent safety of the design. I believe I understand Mr. Sorensen's concerns of enriching the fuel and only have it diluted again when used to "top off" an IMSR. The waste produced may be a problem but, again, this may be acceptable because of other concerns. IMSR and LFTR do have an overlapping market but the market is not completely coincident.

Some concern was mentioned on the absence of Dr. LeBlanc and Dr. Dewan from this forum and I have my own theory. The IMSR is primarily a uranium burner, while thorium has been mentioned as a potential fuel I get the feeling from recent interviews with Dr. LeBlanc that this is not a primary selling point for the design. While I miss reading Dr. LeBlanc's posts here I cannot blame him for not coming here more often. This site is dedicated to thorium as fuel but Dr. LeBlanc wants to sell uranium burners, he may simply feel this site is a poor fit to discuss his designs. It's also quite possible he's just busy.

I also believe much of the same applies to Dr. Dewan. She's likely quite busy. The WAMSR does not use thorium as its primary fuel. I do believe she would be welcome here but this is a site dedicated to discussing energy from thorium, while WAMSR is dedicated to deriving energy from nuclear waste. She may have a lot to discuss on this forum but it may not be a good fit for her time and effort.

I've seen pictures of Mr. Sorensen, Dr. LeBlanc, and Dr. Dewan all together and not biting at each other and gouging out eyeballs so it seems they can get along just fine, at least when the cameras are around. There's room to collaborate and it seems that to some extent that they do by appearing at the same conferences and I'm sure more. In another way they do compete and I prefer it that way, may the best design win. Assuming there is a way to "win" in this competition.
Disclaimer: I am an engineer but not a nuclear engineer, mechanical engineer, chemical engineer, or industrial engineer. My education included electrical, computer, and software engineering.

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Re: Congratulations to David LeBlanc (ORNL)

Post by TerjeP » Sep 19, 2016 9:57 pm

The following document from 1980 has some interesting information on the DMSR design and make up fuel. In particular table 17 on page 31. It shows that the fuel is originally LEU at 20% U235. In years 1, 2 and 3 all that is added is U238 to ensure that the fuel mix does not become too fissile (ie denaturing). It's not until year 4 that they add more fissile. The figures on page 30 are also worth looking at as they show that the power output of the DMSR would vary over the life of the plant based on the changing fuel mix.

http://moltensalt.org/references/static ... M-7207.pdf

It's worth stating that the DMSR and the IMSR are not the same beast. The DMSR described in this document has a 30 year life whilst the IMSR has a 7 year life.

The paper does also somewhat confirm one suspicion that I had. Which is that both the IMSR and the DMSR can probably operate beyond their nominal life if operated at lower average power levels. This could be useful if you buy and IMSR600 but only ever need 400MWth.

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Re: Congratulations to David LeBlanc (ORNL)

Post by Amur_Tiger » Nov 25, 2016 5:18 pm

macpacheco wrote:
Kirk Sorensen wrote:I don't think the IMSR can outperform a CANDU in terms of energy extracted from a unit of natural uranium. Refueling of the IMSR will inevitably lead to a large loss of separative work, and extraction of equilibrium fuel will also result in a loss of separative work.

Solid fueled reactors can remove uranium fuel at enrichments below the average enrichment level of the core. Molten salt reactors, at least those with a single fluid, do not appear to be able to do this. Thus a lot of uranium will be wasted in an IMSR.

Molten-salt reactors offer much more potential when the fissile and fertile materials are chemically distinct. When they are the same (such as in the LEU case) they appear to run into real problems with their fuel cycle.
1 - The most critical aspect with new nuclear is cost / MWe until the revenue starts coming and and time until the revenue starts coming in. If IMSR costs 1/2 of an LWR and 1/3 of a CANDU, most of your arguments are quite mute from a real world business perspective, and we all know, fuel costs are tiny compared to initial investment.
2 - How much make up fuel will be added / year vs startup fuel ? Depending on how much / how little, that loss of separative work could be quite acceptable
3 - How about all of those neutron efficiency gains with having far less neutron poisons in the reactor core, the advantage of having a fairly homogeneous fissile to fertile ratio throughout the operational life of the reactor ? Those advantages help all MSRs. Why wouldn't those advantages offset the disadvantages you claim would be show stoppers ?

PS: I'm not claiming an IMSR will actually cost 1/3 of a CANDU and/or 1/2 of an LWR, but since you took the job to attacking Terrestrial by questioning the data they can't publish since they feel its valuable, I think somebody should suggest some data point at some more optimistic to balance the argument.
My understanding is that fuel makes up a relatively small amount of even operational costs, nevermind the cost of initial investment ( and insurance based on long build times ).

From what I've heard and read about IMSR it should have a fairly easy time getting less cost per MWe in generation, especially if we're limiting scope to Western designs. It would actually be interesting to know just how much money would have to be spent on fuel and waste management to neutralize the advantage of halving the capital costs and workforce ( simpler passive safety suggests that staff on site should go down as well after all).

Edit:

Just to quantify this a bit more the AP-1000s in the US seem to be coming in at around 7 billion each. You'd need the largest IMSR to come in at less then 1.75 billion to beat capital costs at which point it starts to become economically attractive. How realisitc or not is that?

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Re: Congratulations to David LeBlanc (ORNL)

Post by jagdish » Nov 27, 2016 12:13 am

The Canadians wisely went ahead for hundreds of pressure tubes when there was a problem of heavy engineering for reactor vessels. Now that they have more uranium than they can sell, it is quite logical to go for lower capital cost reactors. They may not be interested in breeders.
IMSR may be a good choice for them.

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Re: Congratulations to David LeBlanc (ORNL)

Post by E Ireland » Nov 27, 2016 12:55 am

It appears that new build CANDUs may be back on the agenda - Ontario Hydro has recently increased its estimate of its required quantity of reactor grade heavy water to allow for two new units, and with all but two of its reactors operating it appears the nuclear output drought is over. [The two that are still shut down are Pickering A units that were written off before the other units were overhauled and returned to service]

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