What is the scientific objective of ITER?

[cmb]

I have some problems comprehending what the objective of ITER is.

I'll explain:

The stated objective is "a large-scale scientific experiment that aims to demonstrate that it is possible to produce commercial energy from fusion".

However;
1) ITER will never produce any usable energy, so will not have demonstrated that,
2) ITER is build from 'scratch' materials, from which commercial costings into the future would be just guess-work (the budget seems to keep going up by multi%age annually due to rising material costs - if they've got the materials budget wrong already, how can they predict commercially viable into the future?)
3) ITER is not designed to run continuously, and is, therefore, unlikely to provide any demonstration of a continuous operation which is generally considered necessary for commercial viability
4) According to the ITER press office [I did ask!], it does not yet have any programmed-in testing for tritium breeding. There are modules that have been proposed by the partners (particularly the Russian and Japanese module proposals are strong) which may well be expected to find their way into the programme, but it strikes me as amazing that there is as yet no firm commitment that there will be tritium breeding demonstrated in ITER, and without it then it has not 'closed the loop' on its commercial viability.
5) With a sample of one and operating hours being very 'intermittent', no significant demonstration of meeting a commercial reliability target will have been accomplished.


The stated objective seems to be yet further confused when we consider 'other' tokamak experiments:
A) If ITER is going to demonstrate commercially useful energy, then the next step would be commercially useful energy? NOPE! It is already planned to build a bigger device called DEMO. OK, so if ITER demonstrates commercially useful energy then DEMO will get built... and DEMO's purpose will be... to demonstrate commercially useful energy (?) So what was ITER for again?
B) If ITER fails to demonstrate commercially useful energy, this would only be one experiment on a line of correlation showing 'bigger is better'. So if ITER fails to demonstrate commercial energy, does this mean DEMO won't get built? It would seem unlikely, because that'd mean giving up on the future power source because one experiment out of dozens didn't sit on the line of correlation of all the rest... errr... that's not 'scientific'.
C) If the statement of the objective on the website is wrong and actually ITER is only to 'get some practice in' at running a working tokamak, then why are tokamak experiments being run down now when there are still things that can be learned from them and they'd do OK for such work for some time to come, maybe enabling going straight on to 'DEMO'?

Corollary: DEMO will be built whether ITER does or does not demonstrate commercially useful power. A power station will not be built after ITER, whether it 'works' or not, a power station will only come after DEMO. Many other tokamak experiments still have learning to be gotten out of them, but are being closed down to focus on one experiment, ITER, so ITER does not appear to be a very efficient route to learning how to build DEMO - which is going to be built anyway.

 

[Joseph Chikva]

Yes, scaling or "bigger is better".
But also for proving of so called "Advanced TOKAMAK" concept by which toroidal current after some time of cycle beginning is driven not by induced electric field but by gradient caused with externally injected neutral particles. This concept is proposed for a long time but does not proved yet that might produce current enough for confinement.
Also many engineering challenges should be solved in the frame of program.
As very big first wall structure weighing not less than 5000 t never built before, very large cryostat, mentioned by you breeding modules (as I know not only Russian and Japanese but Korean as well), various testing equipments, etc.
I would agree with you about expediency of funding and its adequacy to the planned purposes.
But financing has been already proved and program is underway.

I would say more: from engineering side of view the very clumsy way of creation of beam of neutrals may be useful for experiments for demonstration of something but never for commercial reactors.

I also do not believe that reactor producing net power after only 600 s (10 minutes) of operation ever can be interesting for commercial usage. As feasible confinement time in TOKAMAKs depends on scaling but that is not infinite at any dimensions.

 

[cmb]

Yes, scaling or "bigger is better".
But also for proving of so called "Advanced TOKAMAK" concept by which toroidal current after some time of cycle beginning is driven not by induced electric field but by gradient caused with externally injected neutral particles. This concept is proposed for a long time but does not proved yet that might produce current enough for confinement.

No, that's not right.

Neutral injection into tokamaks is now well-proven. That is a 'done-that'. And the more power being pumped in the more confinement (to a point), which NBI is good at doing. This is already known.

At JET, they say most fusion work is done with NBI only now. So testing 'NBI' is not the objective of ITER, and even if it were it could be tested in DEMO just as effectively, or more so.

 

[Joseph Chikva]

No, that's not right.

Neutral injection into tokamaks is now well-proven. That is a 'done-that'. And the more power being pumped in the more confinement (to a point), which NBI is good at doing. This is already known.

At JET, they say most fusion work is done with NBI only now. So testing 'NBI' is not the objective of ITER, and even if it were it could be tested in DEMO just as effectively, or more so.

Neutral injection is well-proven for heating.
But not for conversion conventional TOKAMAK into Advanced TOKAMAK by mean creation of so called "bootstrap current" instead of induced current.
As without mega-amperes order current confinement in TOKAMAKs is impossible. But induction is limited in time (e.g. seconds maximum). And as mentioned TOKAMAKs need more than 600s confinement time.
http://w3.pppl.gov/~budny/PDF/PHPAEN174042506_1.pdf

Steady state plasmas are desirable for fusion reactors since the cycling of transient plasmas appears impractical for power generation. DEMO _Ref. 1_ plans to rely on steady state plasmas. ITER _Ref. 2_ plans to explore steady state scenarios having minimal inductive _Ohmic_ current, since inductive currents cannot be sustained for long durations.
One of the goals of ITER experiments will be to produce quasisteady state plasmas with a fusion gain QDT _defined as the ratio of the DT fusion and the external heating powers PDTPext_ _5 for durations of up to 3000 s.

I said "clumsy" because I do not like the solution of joining of TOKAMAK's vacuum chamber with so called atom-conductor (if I am translating correctly) in which is impossible to sustain the same vacuum and vacuum absorbers on the walls are used. This solution may be useful for one shot per day. But not for commercial use.

 

[cmb]

So, what are you trying to say is the objective of ITER that needs to be reached that DEMO won't demonstrate?

 

[Joseph Chikva]

So, what are you trying to say is the objective of ITER that needs to be reached that DEMO won't demonstrate?

Nobody knows anything on DEMO except some projected data.
Unlike ITER that is really funded program being underway.
But it is not self-evident that ITER program participants will achieve the claimed confinement time 3000s (50min).
For note: today's really achieved confinement time has only a fractions of second/seconds order.
And, so, I do not believe in viability of TOKAMAK concept at all.
See also this link: http://iter.rma.ac.be/Stufftodownload/Texts/BurnCriteria.pdf
page 8 LAWSON CRITERION AND REACTOR EFFICIENCY CRITERION:

...tau(b)=560s... In that case a burning cycle would have to last for about 2 h in order to sum up to a life time of 25 years.

 

[cmb]

Your opinion, on tokamak viablilty, is immaterial to whether it has a clear scientific objective that means ITER is a necessary experimental step.

I don't understand its purpose as a useful step in determining if tokamak can provide commercial power.

 

[D H]

I have some problems comprehending what the objective of ITER is.

I'll explain:

The stated objective is "a large-scale scientific experiment that aims to demonstrate that it is possible to produce commercial energy from fusion".

However;
1) ITER will never produce any usable energy, so will not have demonstrated that,
2) ITER is build from 'scratch' materials, from which commercial costings into the future would be just guess-work (the budget seems to keep going up by multi%age annually due to rising material costs - if they've got the materials budget wrong already, how can they predict commercially viable into the future?)
3) ITER is not designed to run continuously, and is, therefore, unlikely to provide any demonstration of a continuous operation which is generally considered necessary for commercial viability
4) According to the ITER press office [I did ask!], it does not yet have any programmed-in testing for tritium breeding. There are modules that have been proposed by the partners (particularly the Russian and Japanese module proposals are strong) which may well be expected to find their way into the programme, but it strikes me as amazing that there is as yet no firm commitment that there will be tritium breeding demonstrated in ITER, and without it then it has not 'closed the loop' on its commercial viability.
5) With a sample of one and operating hours being very 'intermittent', no significant demonstration of meeting a commercial reliability target will have been accomplished.The stated objective seems to be yet further confused when we consider 'other' tokamak experiments:
A) If ITER is going to demonstrate commercially useful energy, then the next step would be commercially useful energy? NOPE! It is already planned to build a bigger device called DEMO. OK, so if ITER demonstrates commercially useful energy then DEMO will get built... and DEMO's purpose will be... to demonstrate commercially useful energy (?) So what was ITER for again?
B) If ITER fails to demonstrate commercially useful energy, this would only be one experiment on a line of correlation showing 'bigger is better'. So if ITER fails to demonstrate commercial energy, does this mean DEMO won't get built? It would seem unlikely, because that'd mean giving up on the future power source because one experiment out of dozens didn't sit on the line of correlation of all the rest... errr... that's not 'scientific'.
C) If the statement of the objective on the website is wrong and actually ITER is only to 'get some practice in' at running a working tokamak, then why are tokamak experiments being run down now when there are still things that can be learned from them and they'd do OK for such work for some time to come, maybe enabling going straight on to 'DEMO'?

Corollary: DEMO will be built whether ITER does or does not demonstrate commercially useful power. A power station will not be built after ITER, whether it 'works' or not, a power station will only come after DEMO. Many other tokamak experiments still have learning to be gotten out of them, but are being closed down to focus on one experiment, ITER, so ITER does not appear to be a very efficient route to learning how to build DEMO - which is going to be built anyway.

This is disingenuous and borders on disinformation.

Your corollary is most likely false. If ITER fails miserably, I strongly that there will be no DEMO. If ITER runs into some markedly tough snags, those aggressive plans for a conceptual design will not be complete by 2017. It is very important to remember that in engineering problems, a conceptual design is a starting point. The conceptual design for ITER was completed in December 1990. The first detailed design took another eight years, and the design was modified significantly after that.

The end goal here is very clear: Commercial fusion power. That would be one heck of a killer app. There's only one problem getting in the way: We are still pretty much clueless on how to accomplish that goal. The science is now fairly well understood; this has become a problem of engineering research rather than scientific research. In engineering, just because you know how to do X doesn't mean you know anything about how to do 10*X. The solution is to take smaller steps and from those smaller steps learn how to get to the end goal.

And that is what ITER is all about. Taking the big huge step at once would result in one thing: Failure. Well, one more thing: An immense amount of money wasted in accomplishing that failure. In fact, even the follow-on DEMO project is not the end goal. It is, as the name suggests, a demonstration. It will inevitably run into some interesting scientific and engineering problems, and solving those problems will help with the next step along the line.

This is how big science / big engineering projects are done. Think back to the Apollo program. The US barely knew how to put a person in space (and hadn't quite accomplished this task) when the project began. As soon as the program was announced (in fact, before the program was announced), a small number of people began working on the Apollo mission itself. They were confronted with a lot of known unknowns, plus some unknown unknowns that they knew were lurking out there somewhere. The project went in stages that ran both serially and in parallel. You can't simply wait for one stage to finish before you start the next. Doing that would result in a project that never went anywhere.

 

[Joseph Chikva]

Your opinion, on tokamak viablilty, is immaterial to whether it has a clear scientific objective that means ITER is a necessary experimental step.

I don't understand its purpose as a useful step in determining if tokamak can provide commercial power.

Objective/objectives?
Very difficult to fix threshold between scientific and engineering objectives but:
• achievement of 3000s of confinement time while previous experiments provide only about 1 second
• beryllium plated first wall.
• testing of various breeding concepts by changing of breeding modules.
• etc
In any case some technologies developing in ITER program's frame may be very useful for another programs.
I have another question: how cost effective ITER program is?

 

[Joseph Chikva]

In engineering, just because you know how to do X doesn't mean you know anything about how to do 10*X. The solution is to take smaller steps and from those smaller steps learn how to get to the end goal.

ITER program has a goal to do 3000*X and some other accompanying things as well.

 

[cmb]

This is disingenuous and borders on disinformation.

Your corollary is most likely false. If ITER fails miserably, I strongly that there will be no DEMO.

Then it sounds like it is not a 'scientific' endeavour, because the science already says that the many existing tokamaks all sit on a well-correlated performance line. All that the event of a failure of ITER should do is to say that it was not built right. You'd not give up on an experiment if step 201 of 200 didn't work right (no matter how big step 200 was), would you? You'd try 200 again, possibly differently, but you'd not throw the whole thing away.

The science is now fairly well understood; this has become a problem of engineering research rather than scientific research. In engineering, just because you know how to do X doesn't mean you know anything about how to do 10*X. The solution is to take smaller steps and from those smaller steps learn how to get to the end goal.

Hence my question; the question is what the relevance is for THIS STEP. How does this fit into the larger scheme? Your argument cannot be 'it is better to break down a problem into the largest number of smallest steps', so I am asking the relevance of ITER as a step by asking what its unique objectives are, or whether it is an unnecessary step arising from political machinations.

As stated, ITER's claimed objective is 'to demonstrate commercial power', which makes no sense because it also states that it will produce no power, no continuous operation nor reliability performance figures, and it has no agreed plans for the evaluation of the required step of tritium breeding. If it's claim was 'to evaluate optimum geometry/plasma control/tritium breeding', whatever, then I'd like to work with that and examine how the proposals/scientific method is approaching whatever objectives are set.

But it isn't. As far as I know, and as far as is in the press, the objective is stated as 'to demonstrate commercial power'.

Hence my question; what is the scientific objective?

If there is no scientific objective, if it is only an engineering matter, then why do we not simply get on and build DEMO, if it is going to be built anyway. Remember, ITER, in its inception, was originally what DEMO was supposed to be but it has gone 'lite' to fit in with objecting political processes. Don't forget this struggled through many years to get any acceptance, and as a result it looks plain to me that the objectives have come out of that mangling process pretty badly altered, to the point of being rather useless.

I'm just looking for an answer to a straight question, the above was just my own personal thinking that has lead me to ask the question; what are the scientific objectives of ITER?

I just think the inertia for ITER is too great (has been for a long time now) for anyone to stop and consider that 'simple' question.

 

[Joseph Chikva]

If there is no scientific objective, if it is only an engineering matter, then why do we not simply get on and build DEMO, if it is going to be built anyway.

The best is the enemy of the good.
If you working on current program will think on more advanced, you will never complete the job.
Financing of ITER is already approved.
Unlike DEMO financing of which will be highly dependent on ITER's success. And about last (ITER's success) I have big doubts.

 

[D H]

Hence my question; the question is what the relevance is for THIS STEP. How does this fit into the larger scheme? Your argument cannot be 'it is better to break down a problem into the largest number of smallest steps', so I am asking the relevance of ITER as a step by asking what its unique objectives are, or whether it is an unnecessary step arising from political machinations.

I never said anything about the largest number of smallest steps. You are once again being disingenuous and disinformative. Stop that!

Ideally you break a large scale science / engineering problem down into the number of steps that maximizes your chances of attaining, minimizes the costs, and minimizes the time needed to reach the end goal. In reality, those conflicting goals. Like the silly better/smarter/cheaper/faster mantra of the 90s and 00s, pick two, maybe three. You can't have all of them.

If anything, given the recent press releases about costs and technical challenges at ITER, this step may well be too large. The reason they aren't building DEMO right now is because that would be far too huge a step right now.

As stated, ITER's claimed objective is 'to demonstrate commercial power', which makes no sense because it also states that it will produce no power, no continuous operation nor reliability performance figures, and it has no agreed plans for the evaluation of the required step of tritium breeding. If it's claim was 'to evaluate optimum geometry/plasma control/tritium breeding', whatever, then I'd like to work with that and examine how the proposals/scientific method is approaching whatever objectives are set.

But it isn't. As far as I know, and as far as is in the press, the objective is stated as 'to demonstrate commercial power'.

Oh please. If you are here to preach, this is not the site for you.

Scientists don't know how to do tritium breeding, at least not anything close to the scale needed by the proposed DEMO project. They have some solid ideas, though. ITER is explicitly serving as a test bed for at least one of those ideas. How is this not meeting your objective for exploring these concepts? This is science at work. If researchers knew what they were doing they wouldn't call it research.

Hence my question; what is the scientific objective?

Stop the disingenuous arguments. Now.

ITER is not CERN. ITER's goal is not to delve into the inner workings of the universe. Its goals are rather explicit. You can find them on many websites. And those goals are scientific. They are goals of applied science and engineering. The borderline between applied science research and engineering research is very fuzzy, perhaps nonexistent. Engineering is applied science, after all.

 

[cmb]

Scientists don't know how to do tritium breeding, at least not anything close to the scale needed by the proposed DEMO project. They have some solid ideas, though. ITER is explicitly serving as a test bed for at least one of those ideas.

Which one? The last time I asked the ITER press office, they said there were no extant plans for tritium breeding. There was the opportunity to include them, I was told, and I have read through some of the proposals made for tritium breeding blanket modules, but that made it implicit that it is a test bed for breeding, at that time of me asking. There may well have been an update in the meantime - do you have a link to the accepted proposal?

I don't understand the objection to asking for clarification on ITER objectives. Getting objectives right should be at the heart of The Scientific Method.

Is there anyone from ITER on the forum that can link to/say what these are?

 

[Joseph Chikva]

Which one? The last time I asked the ITER press office, they said there were no extant plans for tritium breeding. There was the opportunity to include them, I was told, and I have read through some of the proposals made for tritium breeding blanket modules, but that made it implicit that it is a test bed for breeding, at that time of me asking. There may well have been an update in the meantime - do you have a link to the accepted proposal?

As I know there in ITER for checking of various breeding approaches are something like slots in which various types of breeding modules can be inserted.

 

[cmb]

OK, so finally finding an answer to my own question I have come across http://fire.pppl.gov/iter_summary_FDR2001.pdf , page 10 of 80 of which says;

Guidelines and Objectives
The revised performance specifications adopted by the ITER Council in June 1998 are set
out in full in Table 1.3-1; in summary they require ITER:
· to achieve extended burn in inductively-driven deuterium-tritium plasma operation with Q
>= 10 (Q is the ratio of fusion power to auxiliary power injected into the plasma), not
precluding ignition, with an inductive burn duration between 300 and 500 s;
· to aim at demonstrating steady state operation using non-inductive current drive with
Q>=5;
In terms of engineering performance and testing, the design should
· demonstrate availability and integration of essential fusion technologies,
· test components for a future reactor, and
· test tritium breeding module concepts; with a 14 MeV-neutron power load on the first
wall >= 0.5 MW/m2 and fluence >= 0.3 MWa/m2.
In addition, the device should:
· use as far as possible technical solutions and concepts developed and qualified during the
previous period of the EDA, and
· cost about 50% of the direct capital cost of the 1998 ITER Design.

Assuming this is still current; so it appears to have no stated scientific objectives, but rather 'engineering' ones (along the lines of DH's reply).

Does that last line mean it is to be half price of what was originally planned, or that it means the running costs will account for half of the budget?

 

[D H]

Engineering is applied science, cmb.

This thread has gone far enough.