Evil Big Physics is out to fool and deceive us! They don’t explain everything in ordinary language! If Steve Krivit was Fooled, how about Joe Six-Pack?
Krivit continues to rail at alleged deception.
Nov. 7, 2017 EUROfusion’s Role in the ITER Power Deception
All his fuss about language ignores the really big problem with this kind of hot fusion research: it is extremely expensive, it is not clear that it will ever truly be practical, the claims of being environmentally benign are not actually proven, because there are problems with the generation of radioactive waste from reactor materials exposed to high neutron flux; it is simply not clear that this is the best use of research resources.
That is, in fact, a complex problem, not made easier by Krivit’s raucous noises about fraud. Nevertheless, I want to complete this small study of how he approaches the writing of others, in this case, mostly, public relations people working for ITER or related projects.
Krivit exempts the Japanese from his ire.
The Japanese ITER team is the only participating group to clearly and transparently state the power capability of ITER:
“Will ITER make more energy than it consumes? … ITER is about equivalent to a zero (net) power reactor, when the plasma is burning.” (Archive copy)
The original is here. This is from a FAQ with general-public questions. The expression “make more energy than it consumes” is used in three of the questions. That is not asked in scientific language. Here is one of the questions:
Has fusion ever made more energy than it consumes?
In the H bomb as well as the sun, fusion has been shown to work as a source of energy from matter. To make fusion useful for humans on earth the process has to be controlled, and reduced vastly in scale. Contriving this introduces its own problems, as one tries to design the cheapest smallest system which works.
An H-bomb obviously makes more energy “than it consumes.” The criterion being examined is called “break-even.” It is misleading, because energy is not “consumed.” It is moved from form to form and place to place.
So far, the experimental development programme of man-made fusion has not made more energy than consumed. Nor has it worked to produce more power than consumed at any instant.
Again, “consumed.” There are various meanings for this, and Krivit’s Problem is based on differences in meaning. “Consumed” means power input to the plasma, which heats the plasma. If there is some fusion, there will be additional heating power, so the power “produced” is greater than what was “put in.” So the statement made is literally false. JET, they will describe, generated 16 MW of “fusion power.” That is energy release from fusion. So if the input power (plasma heating) was 24 MW, the output power was not 16 MW, but 40 MW. More power than “consumed.”
But that’s not what “breakeven” means. Breakeven really means that the heating power has been “amplified” (what Krivit called a “myth.). The fact is that the best result so far, in a major power experiment is a COP of less than 2.0, i.e., less than “breakeven.” Breakeven is a misleading term because it implies, if one does not reach breakeven, that one has lost something, and Seife fell into that error (and apparently so does Krivit.)
The experimental programmes on JET and TFTR have come closest to “breakeven” – more power out of the plasma than goes in.
It is misleading because all power that goes into the plasma comes out of the plasma. What they really mean is more “fusion power” than “input power,” and, of course, “input power” means what is actually put into the plasma, not all the accessory power usages involved that do not actually contribute to heating the plasma. It’s an experimental criterion, not a full power-plant-assessment criterion.
The record to date is on JET, where 16 MW of fusion power has been produced for 1-2 s. The injected power from plasma heating at that time was about 24 MW, so the power amplification (Q) of the plasma was 0.6, i.e no net gain.
Again, that usage of “net gain” is misleading. There was a gain of 0.6, i.e., heating was 160% of input power.
Of course, to run the plasma and experimental facility, at that time, the site electric power requirement was ~ 100 MW, so for any successful fusion plant Q has to be much larger than in JET.
This is a much lower figure than Krivit uses, I think it was 700 MW. That, however, would be peak power. ITER, using superconducting magnets, may also have a high peak power requirement, but that is only to set up the magnetic field in the first place. Keeping it going will require much less power.
And then the question Krivit looks at:
Will ITER make more energy than it consumes?
Again, they are talking about breakeven.
ITER will produce about 500 MW of fusion power in nominal operation, for pulses of 400 seconds and longer. Typical plasma heating levels duriung the pulse are expected to be about 50 MW, so power amplification (Q) is 10. Thus during the pulse the ITER plasma will create more energy than it consumes.
Notice, again, “fusion power.” This is a totally consistent usage that elsewhere Krivit claims is misleading or a “secondary meaning.”
The efficiency of the heating systems is ~40%.
That, is the 50 MW is actual heating power delivered to the plasma. It is that power that is considered in the “breakeven” criterion. However, the full power delivered to the plasma heating system, then, is 120 MW. There are other “during the pulse” power usages on-site, so they express a total site power of 200 MW, which includes that 120 MW (I assume).
Few are really interested in “total site power,” because of ITER not being designed to minimize it and to reclaim as much of the heating as possible for power generation, so the analysis here is incomplete.
Other site power requirements lead to a total steady power consumption af about 200 MW during the pulse. Now the fusion power of ITER is enhanced by about 20% due to exothermic nuclear reactions in the surrounding materials. If this total thermal power were then converted to electricity at 33% (well within reach of commercial steam turbines), about 200 MW of electrical power would be generated.
So total nuclear power is actually 600 MW because of the blanket reactions, thus they figure 200 MW could be generated by turbines.
Thus ITER is about equivalent to a zero (net) power reactor, when the plasma is burning. Not very useful, but the minimum required for a convincing proof of principle.
Right. Now, if one has a market for heat, that is an additional power output….
In ITER the conversion to electricity will not be made: the production of fusion power by the ITER experiment is too spasmodic for commercial use […]
ITER will carry out tests of electricity production from fusion on a small scale. Some test blanket modules being used to develop power reactor blankets will include a complete steam-raising cycle and turbine in the port cell, allowing the generation of some electrical power even on ITER. The electric power delivered from such a small section of the ITER blanket will be ~ 1 MW.
Krivit likes this because it mentions the inefficiency in the plasma heating and the accessory power. What Krivit doesn’t like is that the information is normally not presented and shaped to his ideas of what a “major breakthrough in fusion power” would look like. ITER is still a research reactor, designed to create plasma breakeven and more (ten times more, actually). That is not enough for self-sustaining power generation, they are still a long way from it. (The “zero net power” is during the burn, which is only for “400 seconds or longer.” Some of the system power will continue outside a burn, such as cryogenics to maintain the superconducting magnets, and the coffee-maker in the cafeteria. Gotta have that coffee!)
The three annotated pages, as shown below, reveal EUROfusion’s failure to achieve its own core values and show its complicity with the ITER power deception.
The motive for the unscientific behavior is easily explained. In the 1970s, fusion proponents told the public that, in the 1990s, fusion reactors would provide virtually limitless pollution-free energy.
I’ve been reading about fusion power since the fifties. If someone made that prediction, they were wearing rose-colored glasses. It has always been considered a very difficult problem, and as plasma fusion reactors were studied, more and more problems appeared. I do not remember any such rosy predictions, only that fusion power might be possible. Someday. And that it was worth studying. Krivit, in telling this story, does not connect the dots between the alleged deceptive language and actual funding. It’s very clear that those who understood the issues were not deceived. Was “the public” deceived? I actually can’t think of any member of the “public” who thought we would have “limitless pollution free-energy energy” by the 1990s. The standard joke has been that fusion power is thirty years in the future, and it has always been thirty years in the future and will always be thirty years in the future. Maybe twenty. I doubt it, at least for hot fusion.
As to LENR or cold fusion, I also doubt “twenty years,” but … maybe. And it is well worth investigation as well. The science comes first, almost certainly. With hot fusion, the physics is understood, that’s the advantage.
However, not one Watt of net thermal power, let alone one Watt of electricity, has ever been produced by controlled nuclear fusion on the Earth.
“Electricity” production has not been the goal of fusion experimentation. Only creating the reaction, which generates heat (and some other effects, and with some forms of fusion, more direct conversion to electrical power may be possible). “Net thermal power” is a misleading concept. JET generated 16 MW of fusion power, so thermal power release in JET was 40 MW. “Not one watt” is, then, very misleading. It’s using the “breakeven” criterion. This is polemic. It’s find a way to state things to make someone look bad.
Fusion advocates have subsequently struggled to keep the public funding flowing for large-scale fusion projects like ITER.
So Krivit imagines that the data is presented this way out of desperation, to make JET and ITER look better than they actually are. Better to whom? No expert has been fooled, and all that Krivit has shown is that some people don’t write with total clarity. … nor does he.
The fact sheet also suggests that the 5,000 Watts of real electrical power can be compared with the 500 MW of thermal power that will be produced by ITER. This, too, is false and misleading because, if thermal output of ITER is converted to electricity with 40% efficiency, the real, usable output is less than zero.
This is s t u p i d. The fact sheet does not “suggest that.” This was, again, a popular explanation. What it actually says:
When will fusion successfully produce useable energy?
The typical U.S. home presently uses about 5,000 watts of electricity on a continuous basis.
That is a simple fact. Why is it stated? Probably to generate a sense of scale. The public has experience with power. Notice “continuous basis.” That’s crucial. Krivit ignores it.
The fusion process has produced more than 10 million watts of fusion energy for about one second in laboratory test reactor experiments from 1994 to 1997. The ITER international fusion project is expected to produce 500 million watts for ~10 minutes by the year 2025. This would establish the scientific basis for a fusion power plant that could be built in the 2040s for the large-scale production of carbon-free electricity.
This is work to establish a “scientific basis.” There is nothing offensive here. Let’s use the 10 MW figure. For one second. How does that compare with 5 KW “on a continuous basis”? 10 MW for one second is about 2.8 KW-hr. So those tests released as much fusion energy as would match the heat released from electrical power in a single ordinary home in a little over a half hour.
And it was a huge accomplishment!
Krivit is probably upset because they are not making it clear that these reactors did not produce electricity and, mostly, ITER won’t. So it is possible to misunderstand. That’s all. Does this actually matter? How?
Krivit goes on with more specific critiques. Those fuzzy-headed physicisits and their overpaid publicists keep getting in WRONG!
He points to the Eurofusion FAQ. and defaces it with his interpretation:
The ITER reactor is actually expected to produce 1.6 times the power consumed. Eurofusion does not show this value anywhere on their web site.
Of course it doesn’t. It’s a bogus figure Krivit invented by using his own vague and unexplained definitions of words (he also plays fast and loose elsewhere with “fusion.”) ITER is a research reactor, and a goal is to reach and exceed “breakeven” — a term that is specially defined and that actually does not mean what an ordinary person might think, it means *more* than that. That slippage of meanings is how Seife could make his mistake in thinking that JET “lost” power. As the Japanese site shows, ITER will actually produce 600 MW thermal — and possibly more than that, perhaps 650 MW; 500 MW is only “fusion power.” Which is what they are studying!
Most descriptions of JET and ITER — and historically, other devices, I think, — use “input power” to refer to plasma heating power, since that is what directly controls fusion rate. It does not refer, for example, to the energy used to keep cool the ITER superconducting magnets. In a mature plant, that cooling might be powered by plant heat, avoiding the inefficiency of electrical conversion. These are engineering considerations. ITER simply is not yet at that stage of research, it is far from what would be needed. The next plant, DEMO, is planned to approach that.
This is what is actually in that FAQ, and it seems accurate, given the standard meanings of the terms. It does not appear to be misleading outside of Krivit’s narrow and personal interpretation:
Since ITER is expected to produce 10 times the power consumed, does this not mean that the substance produced and reused will by further extrapolation reduce the power needed by a reduction of 10? And this reduction lead to a further reduction of 10 and so on until almost no power is used?
It’s a weirdly worded question. It uses vague concepts of “consumed” — as is common — and “used,” and “substance produced.” However, it is talking about becoming self-powered, and that’s the question they answer.
ITER will generate fusion power that is ten times more than the power used to directly heat the plasma. Additional power is required for the magnetic field coils, although this will be much reduced at ITER as they will be superconducting. Nonetheless, as you suggest, in the fusion process there will be more power produced than is consumed – as indeed there is in any power plant.
They start off with the correct explanation of the 50 MW “input power,” it is called elsewhere. The power used to directly heat the plasma. They do not explain that this is not “plasma heating system power input,” it is only the energy that is actually dumped into the plasma, and it neglects the inefficiencies of the conversion system, from electrical power to plasma heating power. But … at ignition, the plasma heating becomes unnecessary, and at ignition, the Q goes to infinity. ITER is designed to test ignition, among other things. “Ignition” does not eliminate all system electrical inputs, so the power plant question would be the generation of electrical power from the fusion energy. That is not an ITER issue, there is no attempt to become independent of grid power. However, Krivit probably is overstating the electrical power requirements. As he did with JET, he may have used peak available power (which was 700 MW for JET, as I recall) as if it were consumed during the burn.
The energy produced by the fusion reaction is mostly carried by the neutrons, which, because they are neutral in charge, are not affected by the magnetic field that confines the plasma. Instead they stream out of the plasma into the walls of the vessel where their energy can be collected and used to heat water, as in a conventional power plant.
Right. Additional power, the Japanese estimate 100 MW, is released by other nuclear reactions in the blanket. So total nuclear energy is 600 MW.
The other product, the helium nucleus, carries only 20% of the energy, but because it is charged, it stays within the plasma. So you are correct, this energetic “substance” contributes to the heating of the plasma, and replaces the need for extermal heating. At a certain point the heating caused by the helium production will be enough to turn off the external heating systems completely – this point is known as ignition – and as you point out, no further input power would be required at that stage.
Again, “input power” here means plasma heating only. The Japanese estimate total input system power of 200 MW. Where Krivit gets his ratio of “1.6” from, I don’t know. At ignition, this could be reduced by 50 MW, perhaps. So system power would be 150 MW. At an efficiency of 33%, the heat could generate 200 MW, so net *electrical power* could be 50 MW.
For how many minutes? But all this is purely theoretical, because ITER will only have a small steam generator to test the concept.
However, for the sake of controlling the plasma, future power plants will probably operate slightly below the ignition point (although this still will produce significantly more energy output than is put in.)
I would think that with 500 MW power, and 20% of that being energetic helium, they would have 100 MW of plasma heating and it would be ignition. So they are not being clear about this, but this is only a brief, non-technical discussion for a FAQ, not a complete exposition.
It is not misleading.
Krivit also complains that “the additional power required for the reactor to operate” mentioned by the FAQ is “not a trivial amount.” They did not state that it was. Krivit has:
In fact, it’s six times more than the power used to heat the plasma.
Apparently not. What Krivit has done is to ask a lot of questions of people with varying degrees of knowledge, some of whom gave him estimates, but Krivit is never clear about the distinction between peak power and average power or power during the burn, so he doesn’t actually know what questions to ask and how to interpret the answers.
He does not do a careful analysis with clearly confirmed figures. He is probably using a figure of 300 MW as total system power input, and that may be peak power, much more than used during the burn. The Japanese, who probably know a lot more than Krivit, as ITER participants, use 200 MW, and that apparently includes plasma input power, with the plasma system having electrical power consumption of about 125 MW. As ignition is approached, that plasma input power would decline. The overhead power (mostly refrigeration, I think), could then be about 75 MW. If they can, with DEMO, obtain the same fusion power (500 MW, leading to 600 MW heating of the blanket), they could generate 200 MW. Power available to “sell” would then be about 125 MW.
This is a very rough estimate based on figures that were not collected and reported for the purpose. Krivit, however, has apparently exaggerated the information, skewing it the Krivit Way, turning it all into his long-term Favorite Story: Deception! Fraud!
His next example of “deception” is a rant on “fusion power.” It is apparent that Krivit thinks that this term should refer to “generated and usable electricity,” which is actually a secondary meaning, derived from the primary meaning, which would be the ordinary linguistic meaning: fusion power would be power released by fusion, a form of nuclear power. That power may then be used, under some conditions, to generate electrical power. There were proposals, many years ago, to detonate thermonuclear devices underground and then pump water into the cavity, converting the generated steam to electricity. This would be fusion power in the primary meaning (the power released in the explosion) and in the secondary meaning (which Krivit thinks, apparently, is the primary meaning, hence all his fuss, even though ITER and other sources never actually say that; but there are certainly ideas that eventually fusion will be used for electrical power generation).
There is nothing seriously wrong with what ITER actually wrote. There is the usual confusion about breakeven, breakeven being a rather artificial boundary of not much significance. Breakeven is equivalent to a COP of 2.0. And then there are many details which could be highly confusing, such as duration, repetition rate, overhead power, etc.
ITER, the world’s largest and most advanced fusion experiment, will be the first magnetic confinement device to produce a net surplus of fusion energy.
“Net surplus” comes from the breakeven criterion. Any fusion device produces a “surplus” of energy. “Net surplus” is misleading language which became common. If I have a store and I invest money in inventory and sell the inventory for more than I paid for it, the excess is called “net profit,” but the actual income is the full amount of the sales. However, net profit will be separated out in a tax return (and then inventory adjustments will also be considered). That I have “net profit from sales” does not mean that the business has a profit. There are overhead and other costs to consider, some of which will vary with sales, some not.
The breakeven criterion seems to treat a 50% margin as the minimum to have an “energy profit.” That is preposterous! If the energy generation system were cheap, that might be well worth operating. (If Rossi’s devices had actually worked at a COP of 2.0, and if they were cheap to operate, which seemed possible, absent his fraud, power could have been sold at a profit to heating co-ops. Heating power. No conversion to electricity needed.)
The breakeven criterion only applies to the plasma itself, and is actually significant for ignition, the state where the plasma self-heats. But because 80% of the fusion power escapes the plasma as neutrons, breakeven is not enough for ignition, instead of the artificial 1:1 of breakeven, 5:1 is needed for enough power to remain in the plasma to keep it hot enough for significant fusion rate. ITER is designed to reach 10:1 (though many details are missing), so then the next steps become reasonably possible. This is what they are talking about.
It is designed to generate 500 MW fusion power which is equivalent to the capacity of a medium size power plant. As the injected power will be 50 MW, this corresponds to a fusion gain Q=10. ITER will also demonstrate the main technologies for a fusion power plant. ITER is currently being built in southern France in the framework of a collaboration between China, Europe, India, Japan, Korea, Russia and the USA.
The mention of a “medium size power plant” is apparently only to put the number in perspective. However, that “medium size power plant” is designed to run continuously, whereas ITER might burn for 400 seconds or so. ITER is nowhere close to the “operating capacity” of a “medium size power plant.” I see no intention to deceive here, to Krivit, intentional deception is his bread and butter.
Krivit is focusing on secondary meanings, ignoring the primary purpose of each of these statements, which is simply to explain, using accessible comparisons. The core meaning is that ITER will “demonstrate the main technologies for a fusion power plant.” Not all of them.
The realisation of fusion energy depends fully on ITER’s success. ITER is the central facility of the Fusion Roadmap and therefore the EUROfusion research programme is dedicated to ITER and its accompanying experiments.
It’s a research program, not an electric power generation plant.
“Fusion power” in this instance, is deceptive. That 500 MW value is not usable power. It is only the power of the plasma, not of the reactor.
ITER is designed to test the plasma, not an entire power plant system. “Fusion power” is indeed the “power of the plasma,” but that is not the entire plasma heating power. The 500 MW is additive to whatever power is used to heat the plasma to operating temperature. As well, only some of the 500 MW appears in the plasma, most (about 80%) escapes the plasma as neutrons and heats the blanket, as well as causing an additional 100 MW worth of other nuclear reactions there. Krivit has only a very primitive idea of what ITER will actually. But he is certain they are deceptive! That’s the theme, it’s core for him.
EUROfusion does not define the secondary meaning of the term “fusion power” anywhere on its Web site.
Krivit also never defines the “primary meaning.” What he calls “the secondary meaning” is the ordinary, common, linguistic meaning. “Nuclear power” has an ordinary meaning. But then, because this ordinary “nuclear power” is used to generate electricity, a secondary meaning can be “electrical power generated from nuclear power.” So if we say that X% of U.S. electrical power generation is “nuclear power,” we would be referring to the secondary meaning.
There is no electrical power that has been generated from “fusion power.” Nobody has claimed it. There is only a release of “fusion power” as heat (and then secondary reactions, neglected in the reaction Q).
It’s not defined the way that Krivit wants it to be defined, out of his own yellow-journalist fanaticism.
The reactor will actually consume 300 MW of electricity.
That figure appears to be incorrect. And Krivit is imprecise about what “the reactor” means. “Reactor” can be used imprecisely, and has been. If there is a cost in the preparation of fuel, if it takes energy to find and create usable fuel (as it does with fossil fuels in general), that is not included in a basic budget for a generator boiler. Electrical power cannot just be fed directly into the plasma, it must be converted, perhaps to radio-frequency oscillations, which is not necessarily efficient (though this is a matter of engineering, and ITER would not necessarily be designed to maximize efficiency, that would be a premature cost, not necessary for ITER purposes. Still, that preparation cost or inefficiency in what is actually delivered to the plasma is not part of considering what actually happens in the reactor, and if ignition is reached, this extra cost would disappear (except for start-up, and, then, the significance of that cost would depend on duration of burn and repetition rate, all complexities that Krivit totally ignores.)
The Japanese said “200 MW,” not “300 MW,” and that was considering full input power, not reduced to back away from ignition. Krivit then seems to imagine that this 300 MW vanishes. In fact, some of it is stored and recovered, and most of it ends up as heating power. Krivit makes quite the same mistake as Seife.
If the net 200 W thermal power that will be produced by ITER is converted to electricity (conversion is not part of the ITER design), the reactor would undergo a net loss of 100 MW.
Krivit is thinking of “net thermal power,” which is meaningless, it is only a calculated figure used in the breakeven criterion. It is not at all a practical figure. In fact, the heating power of the ITER reactor would include all heat dissipation that does not escape the recovery system. As Krivit knows, ITER is not designed to recover the thermal power and convert it to heat, though there will apparently be a pilot project working with a about a megawatt.
I do not know if the ITER people have been asked the necessary questions to be able to estimiate what would be actual power generation figures, but Krivit is definitely and obviously incorrect.
The reactor will heat its heat recovery system, when such is in place, with a full heating power of about 650 MW during a burn, being 500 MW of fusion power, 100 MW of secondary reaction power (this appears in the blanket, not in the plasma), and 50 MW of plasma heating, power actually delivered to the plasma. A sophisticated system would also recover heat from the plasma heating system inefficiency. It’s all heat, but neglect that.
The site power consumption during a burn is not 300 MW. Where did Krivit get this number? His original story makes what may be a similar error with JET, confusing peak power with burn power, 700 MW apparently being the peak available power (which was also supplemented with flywheel accumulators to provide peak power even higher than 700 MW — but I’m not completely clear on that) — this was all considered unimportant with JET, because most of that power was used to create and maintain the very strong magnetic fields needed for confinement, but that is not a power that appears in the plasma, and superconducting magnets would radically change this; JET was purely to research the plasma itself.
Reviewing his older “supplement,” it’s clear that Krivit thinks that “power” should mean “electricity,” that this is the “primary meaning.” Thus is created the alleged deception. But was there any actual deception? Did anyone actually think that JET generated 16 MW of electricity? Does anyone actually think that ITER is supposed to generate 500 MW of electricity? If anyone thinks that, they have not been paying attention! Krivit had formed knee-jerk ideas, apparently years earlier, and was horrified to find that these were wrong. And his predilection is to blame others for his own errors, so that’s what he’s doing. In his enthusiasm for identifying the errors of others, he doesn’t notice his own, or minimizes them. Too common. We all need to watch out for this one!
But where does his figure of 300 MW come from. Apparently it is from a EUROfusion document (his archive, from the original) that explains 700 MW for JET. This is not a definitive source, necessarily the exact meanings are not clear, but it has this:
How much power is needed to start the reactor and to keep it working?
JET consumes large amounts of power – for fusion to occur we need to create and maintain plasma at extremely high temperatures. Additionally we need to contain the plasma by energising large magnetic coils. In total, when JET runs, it consumes 700 – 800 MW of electrical power (the equivalent of 1-2% of the UK’s total electricity usage!).
This is what I had always understood. JET required a very special connection to the UK grid, and operated off-peak to avoid causing major problems. They are hardly concealing this!
Future reactors will use superconducting magnetic coils, which are much more efficient, so they will not expect to use so much power – maybe 200-300 MW of electrical power. They will produce 1-2GW (1000 – 2000 MW) of electricity, whereas JET does not have the set up to harvest any energy produced, as it is not a power reactor, but an experiment.
This is not talking about ITER, but it does refer to 300 MW (as the upper end of a range) and it is not carefully worded. It is also referring to electrical power and ITER, like JET, is not “set up” to harvest any energy produced, but is “an experiment.”
The power required to keep a reactor working is an interesting question. Energy input is required to keep the plasma hot, because most of the energy produced by fusion is carried away by the neutrons. However 20% is carried by the helium nuclei, which remain within the plasma, so it is possible to reach a point called ignition, at which the production of hot helium is enough to sustain the plasma and the external energy sources can be turned off. It is not clear yet however whether that will be the optimum operating regime in a power plant – being slightly below ignition may give better control of the reactor (while still producing plenty of hot neutrons).
Again, not very carefully worded, but not deceptive. At a Q of 5, ignition may be possible. A Q of 10 is the figure that is most often mentioned for ITER, and it is specifically the ratio between plasma heating power and fusion power.
As many experts attempted to explain to Krivit (see his early posts on this), the so-called “net power” is not only not important, but could be quite misleading. Is the above his only source?
This document mentions “a plasma shot will require an input of 300 MW.” However, the significance is unclear. It is not the purpose of this document to show the power balance, and it is not specified whether or not that power is required instantaneously, i.e., peak power, or must be continuous, during the shot, or is outside of shot power.
I find other documents that gave 300 MW as “input power to the plasma” for ITER. And an indication that this power is or includes the “alpha heating power.” That would actually be fusion power, i.e., fusion produces hot alphas, which will heat the plasma. I don’t know that anyone has yet asked the questions to be able to address what Krivit addresses.
This source casts everything into doubt. It gives the total planned power of ITER as 1.5 GW, and then 300 MW as “alpha heating power.” (That would be 20% of the total fusion power). I now know enough about this to be thoroughly confused. (Remember, the saying, “if you are not confused, you are not paying attention.”)
This fairly recent document on the ITR Cooling WaterSystem gives “the heat generated in the Tokamak” as 847 MW. There would be additional heat generated in the blanket. It also gives “incoming heat during “short duration pulses” as 1.15 GW (and then the sustained input as a “small fraction of that.”)
I am guessing that the sustained input is about 50 MW, which then would explain the other claims.