Fusion fuel -got any in multi-gigawatt amounts!!

Reflections on fusion history, current events, and predictions for the 'fusion powered future.
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Richard Hull
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Fusion fuel -got any in multi-gigawatt amounts!!

Post by Richard Hull » Wed Sep 17, 2008 8:05 pm

Since this is about the future of fusion, we need to talk about the fuel.

Right now 100% of the effort and 100% of the dollars are in D-T fusion with little hope of success or real power from a winning system from this fuel for another 30++ years.

So, let us say the real soon now becomes right now and D-T is perfected. Any one figure out how much T needs to be on hand and in the gas lines of the multigigawatt fusion power stations? It is very calculable. We don't have it and can't get it in the quantity needed, of course. How many nuclear fission plants will be needed to make it?

OK, OK, so we really use another fuel. Among the easys are D-D and D-He3. There is even less He3 than T! The mining of the moon is way off. Thus, D-D is the optimum available fusion fuel inspite of its neutronic nature and lousy energy return per fusion compared to D-T. D-D is a doable thing with enough water to D extraction plants working off fission power. That is still a lot of D that is going to be needed.

Some will say well once we tackle fusion, regardless of the fuel, we will be able to burn anything and P-B11 is just all over the place. B-11 ain't a gas and not much has been done in the way of securing the methodology of handling gigawatt yielding amounts of hazardous Borane or BF3.

Yes, this is just engineering, but still, will the fusion fuel be ready for a winning fusion system or will we be another 10 years after fusion success just breeding and stockpiling fuel?

We just will not be using D-T at the giga or terawatt level if the current fusion effort ever goes as the stary-eyed proponents plan.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Chris Bradley
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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by Chris Bradley » Wed Sep 17, 2008 10:00 pm

This was the point I was banging on about in;

viewtopic.php?f=15&t=7165#p49037

You point is right and which is where I am fundamentally confused over ITER. Is it an experiment, a proof-of-concept, or is it a piece of engineering?

It is possible to produce tritium by breeding it in the lithium jackets of a neutron emitting fusion reactor. Doing so also produces a good supply of energy in itself. Of course, you need one-to-one correspondence of a tritium nucleus synthesised for each neutron coming out to maintain enough fuel for tritium 'self-sufficiency' and for sure a goodly percentage will be lost, so the idea is to bung in some beryllium aswell which produces a shower of *extra* neutrons (if there aren't already enough flying around) through an endothermic reaction to keep the whole chain going.

Now, you'd think that if this were really the plan that somewhere along the line someone would want to prove that this process of tritium breeding is viable. And there are a couple - I believe the Russians and the Japanese want to see an ITER vessel tritium-breeding test jacket included. But it has never 'formally' been part of ITER and has not been accepted yet as part of the programme.

So ITER is still *just* testing out plasma control and still hasn't even reached the baseline of proof-of-concept because it's got no fuel supply! Some seem to think that this is actually a piece of 'test engineering' for the DEMO power-producing reactor to follow - but it clearly isn't.

best regards,

Chris MB.

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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by Starfire » Wed Sep 17, 2008 10:10 pm

The holy grail ITER concept is to achieve a temperature high enough for a fusion reaction - squeeze more into a smaller space - faster.

Perhaps you should attend a plasma physics summer school Chris

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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by DaveC » Wed Sep 17, 2008 10:46 pm

I thought ITER was actually a Weapons Test Device, cloaked as a fusion development system. It was never intended to be a practical prototype for a true steady state Fusion reactor.


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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by Chris Bradley » Thu Sep 18, 2008 10:48 am

But this is my point – getting a fusion reaction going ISN’T what ITER’s mission is. ITER is trying to improve what is considered ‘known’ (which is unity power output as shown by JET) to the point where there is power amplification.

This is just jumping the gun and it seems to me there is a whole lot more that can be done with existing tokamaks, particularly JET, to get more knowledge of plasma stability BEFORE committing the ITER design.

For example, the design for ITER has been kicking around for decades, but it’s only in the last year or two that it’s been decided edge-instability-disrupting antennas are required (from the research in other tokamaks), hence a modified design has been recently submitted. How many more such realisations might occur if the effort is put into those projects?

ITER’s original principal purpose was to get an experiment going to test out materials. At its inception it was presumed that actual fusion plasmas were going to be a done-deal so the issue was more to do with researching and proving the materials to a standard to resist a constant neutron flux and to engineer the size required as demonstrated by extrapolation of existing tokamaks.

Tritium breeding is also meant to be a technical objective, but it has never been planned for in the project excepting leaving it to national participants to propose their own vessel-wall module projects, and as far as I am told this remains undecided. So – no tritium synthesis means it is no proof-of-concept. This is covering Richard’s point.

So with the design evolving as we speak, and with some technical objectives being missed off, it seems to me that ITER is now an experiment that has lost its way but has so much inertia towards an unclear set of goals that no-one can stop it. The experimenters are now under the control of the experiment and no-one involved in it seems able to recognise this.

I do not know if ‘Spiderman 2’ was intentionally meant to be such a direct critique of experiments like ITER [in the film, the ‘intelligent fusion arms’ take over the experimenter, then together they run amok], but it is said that fact often follows fiction!

So whatever we have heard from those involved and running the project, you get a different perspective if you stand back from it and are not ‘under its control’. It seems evident to me that those involved in it may not be the ones best placed to comment on the ‘bigger picture’ of what its historical/unique technical contribution to the evolution of fusion power is intended to be.

I do not question the science and experiment of ITER itself, I am questioning its very purpose. It is not currently planning to prove tritium breeding is viable, and everything else it aims to do appears possible with existing experiments. For a project of this scale, I see no point at all in aiming for power amplification (its only real objective) if there is no proof-of-concept for energy extraction of that power and fuel synthesis shown to be viable at the same time.

best regards,

Chris MB.

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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by Richard Hull » Thu Sep 18, 2008 2:13 pm

ITER was never a weapons test system........That is NIF (National Ignition Facility) It was created as part of the "Stockpile Stewardship" effort. A side arm that helped it get funded was "Hey!... We can also use the big numerous terawatt laser bank to investigate controlled power fusion!" "please boost our budget!"

NIF is rarely heard about now after a horrid debacle in mid course showed just how mismanagement can be found in the science Biz as well as big biz.

viewtopic.php?f=22&t=8174&hilit=NIF#p57846

NIF will do what it will to test more efficient nuke weapons ideas and, as time permits, will put on a show about laser confinement fusion complete with all the usual hype and promise in the media.

ITER 'is engineering' only in the sense that they have to physically assemble something that they hope functions as advertised. It is 'a proof of concept' only in that D-T is absolutely the easiest form of hot fusion in the universe and we can't seem to do it to any power ready advantage. They pray that if it goes, then they can lean back in their chairs, fold their hands and say that fusion of scrap meat and vegatables can be reduced to mere engineering challenges. (I don't think so Tim).

Alas, as always, we peer through the fusion store's window, expectant, with our noses pressed against the glass in wonderment.

D-D fusion is the winner. If we can get D-D to go (vastly more difficult) we will be really making tritium fuel to spike the reaction in a multi-megawatt fusion reactor.

There will always be the P-B11 hangers on.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by mheslep » Sun Sep 21, 2008 11:22 pm

One of ITER's goals is to test the effectiveness of producing tritium from a lithium blanket:
Li + n → He ( 2.05 MeV ) + T ( 2.75 MeV )
Most of ITER's actual power testing will apparently be done with externally produced tritium, I believe its coming from Canada.
http://www.iter.org/fuel.htm
http://www.fusion.ucla.edu/abdou/abdou% ... 20al_1.pdf

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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by Chris Bradley » Sun Sep 21, 2008 11:51 pm

A couple of points:

ITER will have no 'power testing', it'll just have 'testing'. It can't make any power.

ALL of ITER's testing will be done by externally produced tritium. It will never make a single atom of tritium that it reburns for itself. (You'd imagine that if you were trying to show a proof-of-concept for a power supply that re-generates one of its fuel components that it'd be important to show that works, but this is not the case with ITER.)

This is an old report and it says "A decision on the types of TBMs allowed in ITER is scheduled in 2005." ...and that decision point has come and gone with no conclusion...

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Chris MB.

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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by mheslep » Mon Sep 22, 2008 12:19 am

The ITER website itself is fairly current if you want more information.

Yes by 'power' there I meant ITER maximum output, and not just the odd neutron fired into the Li blanket to test tritium production. Also, it is likely that ITER will indeed produce 10X more heat energy (not electric energy) out than is fed into the plasma for some minutes. The problem is more in the practicality of ITER. Q=10X, with ITER's great size, is not enough to compete with the alternatives including the most expensive fission plants, waste included.

Anyway, to stay on topic, I don't believe the fuel stock is a problem as Lithium is abundant. Storing kilotons of the stuff will be the trouble. Tritium storage is not mentioned now because there's just so little of it. Scaling up a million fold will change that.

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Re: Fusion fuel -got any in multi-gigawatt amounts!!

Post by Chris Bradley » Mon Sep 22, 2008 8:53 am

I would like to clarify my position, as I have what may appear a mixed view on ITER:

If ITER were really a 5 billion science experiment, I'd be all for it and a strong advocate. Likely success or failure - irrelevant. Just get on and do it!

But ITER has followed a political trajectory for many years now and I do not think it will break away from that. It has promised much yet could deliver nothing. It is a lurching mongrel of a machine that has yawed off the launch pad and is following a trajectory that looks like it will end up in a crash landing over the horizon somewhere.

I feel tritium breeding is the proof, if proof were needed. The timetable I have reads '2021: Short term tritium breeding'. So far so good. Then you read a little further and realise that there is no actual plan yet. There are a pile of proposals from partner countries, as attached, all of which are good ideas, none of which have ever been assembled as a 'thing' to see if it works.

When the first 35 billion of funding dries up after running 10 years late having never got that far in the programme, the tritum breeding will be a long lost hoped-for abandoned memory.

It's a bit like me saying "right, here's my programme to make fusors self-sufficient: here's the build plan..... good, got the funding and we've got that going..... oh yes, incidentally, whilst we're building this thing maybe we should decide which is the best proposal to get net-neutron break-even".

I recognise that tritium breeding is somewhat already a 'known science' but I think it is currently made by endothermic deuterium irradiation at CANDU rather than by exothermic lithium, and also NOT in the quantities required. Richard's original post is essentially correct and I feel is a critique that should have been closed down long before they started clearing the Cadarache site.

best regards,

Chris MB.
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