How many Fusion Power Plants to power humanity?

[gmax137]

Roughly 8.2 × 10^13 joules

Yes, if every atom in the kilo of U is fissioned.

Handy thumbrule: fissioning 1 gram releases 1 MW-day (actually it is 1.052 grams, but ...)

 

[Paul Uszak]

but are not required their elements

What are you suggesting my computer could be made of instead (this century)? And my t-shirt for that matter?

 

[mheslep]

What are you suggesting my computer could be made of instead (this century)? And my t-shirt for that matter?

Same elements, carbon and hydrogen, which need not come from oil. Methane for instance is replacing oil in the U.S. as a raw material for plastic. Then there is scrap plastic and eventually synthetics.

 

[mheslep]

Yes, if every atom in the kilo of U is fissioned.

Handy thumbrule: fissioning 1 gram releases 1 MW-day (actually it is 1.052 grams, but ...)

Right, or 1000 GW-day per ton, with actual burn up at 40 GW-day per ton up to 500 GW-day per ton theoretical designs.

 

[Stephanus]

Chernobyl is not uninhabitable by any means, many people still work there and plant and animal life is not significantly affected. The high level radioactive Cs and Sr will be gone in 100-200 years. To answer your question though, a fission power reactor contains vastly more fuel and fission products than a bomb. A bomb contains 50 kg of U while a reactor contains 50 tons. A reactor produces as much energy as a fission bomb every ~6 hours and runs continuously for years.

https://en.wikipedia.org/wiki/TNT_equivalent
1 kg TNT = 4.7MJ or 4.7GJ/ton.
If fission power plant produces 1.5GW (doesn't have to higher than coal power plant, right? The difference is the fuel) so, 6 hours ≈ 32.4 TW,
15K TNT = 4.7GJ * 15000 = 70.5TW, so perhaps power plant output is not 1.5, higher? Comparing with which nuclear bomb? Little Boy? Ivy Mike? Tsar Bomba?

 

[Stephanus]

[..]A bomb contains 50 kg of U while a reactor contains 50 tons.

What??
For 50 Kg Uranium in Little Boy it produces 15KT TNT, but not all reacted only 1 kg from what I read.
https://en.wikipedia.org/wiki/Little_Boy#Project_Ichiban
What if there were a screwed up in the reactor. And those 50 tons reacted at once? Ivy Mike? Tsar Bomba?

 

[Astronuc]

What??
For 50 Kg Uranium in Little Boy it produces 15KT TNT, but not all reacted only 1 kg from what I read.
https://en.wikipedia.org/wiki/Little_Boy#Project_Ichiban
What if there were a screwed up in the reactor. And those 50 tons reacted at once? Ivy Mike? Tsar Bomba?

Two very different situations!

Nuclear plants use low enriched uranium and most, e.g., LWR or graphite reactors, are moderated, and are under strict reactivity control. We don't do prompt supercritical, which is the basis of Little Boy and other systems designed for their purpose.

This discussion has gone way off topic from fusion into fission systems, which do not apply to the original question. If the OP would ask, "How many nuclear plants do we need to supply humanity . . . ?" It depends on how much power, the capacity and the efficiency. Then there are the costs to build, operate and maintain, salvage and/or scrap, and waste disposition - as compared to alternatives.

We could also reduce demand by eliminating advertisements, which are mostly spam IMO.

 

[Stephanus]

Nuclear plants use low enriched uranium and most, e.g., LWR or graphite reactors, are moderated, and are under strict reactivity control. We don't do prompt supercritical, which is the basis of Little Boy and other systems designed for their purpose.

Ahh, I should have remembered Russ_watters answer to my question

[..]Well, what you describe - all of the fuel reacting at once - isn't really possible in a nuclear plant. The fuel is not anywhere close to dense enough to explode like a nuclear bomb.[..]

[..]This discussion has gone way off topic from fusion into fission systems, which do not apply to the original question. If the OP would ask, "How many nuclear plants do we need to supply humanity . . . ?" It depends on how much power, the capacity and the efficiency. Then there are the costs to build, operate and maintain, salvage and/or scrap, and waste disposition - as compared to alternatives.

Yes, the number of fusion plant doesn't necesseraly smaller than coal plant, all that should be calculated here is the power output. 1.5GW? And from the previous answer, I also learned that the cost is not much smaller than coal plant. Or let's say conventional plant.
But the benefit of fusion plant is the pollution greatly reduced. And for political reason? I think this greatly affect GEOpolitical situation. In conventional and fission plant, even if the nation has the technology, the fuel is limited to some geographical location. But fusion fuel is everywhere. Isn't necesserally the ocean. Lake water, river, soil water, everything. They have 1 deuterium for every 6500 hydrogen.

 

[QuantumPion]

https://en.wikipedia.org/wiki/TNT_equivalent
1 kg TNT = 4.7MJ or 4.7GJ/ton.
If fission power plant produces 1.5GW (doesn't have to higher than coal power plant, right? The difference is the fuel) so, 6 hours ≈ 32.4 TW,
15K TNT = 4.7GJ * 15000 = 70.5TW, so perhaps power plant output is not 1.5, higher? Comparing with which nuclear bomb? Little Boy? Ivy Mike? Tsar Bomba?

Typical power reactors produce 2500-3500 MWt. The newer fission power plants produce over 4000 MWt. 4000 MW * 6 hours = 20 kilotons TNT.

What??
For 50 Kg Uranium in Little Boy it produces 15KT TNT, but not all reacted only 1 kg from what I read.
https://en.wikipedia.org/wiki/Little_Boy#Project_Ichiban
What if there were a screwed up in the reactor. And those 50 tons reacted at once? Ivy Mike? Tsar Bomba?

A commercial power reactor does not have enough reactivity to release all of its energy quickly as a bomb so it's not physically possible. Chernobyl was pretty much the worst that could possibly happen.

 

[DEvens]

Re: You don't need to mine anything for a fusion reactor.

The usual reaction contemplated for fusion power is D-T. The D comes from water. At this moment we have a significant over-supply of heavy water just sitting around. Ontario alone could probably sell you 100 tonnes of D2O without feeling a pinch. In fact, the heavy water plant used to be at Bruce Nuclear Power Station, and ran off one of the reactors. I forget how much power it required, but it was some 10's of MW. The major issues with a heavy water extraction process are that it requires substantial power input, and it tosses around chemicals that are highly poisonous and highly flammable. But it only needs some tens of tonnes of such chemicals. It is a very easily solved problem. World supply of D could easily be produced from a plant the size of the one that used to be at Bruce.

But the T coms from exposing Lithium to neutrons. Lithium you need to mine. However, we already mine a lot of Lithium. The issue there seems to be it will compete with battery production. But it probably will not hurt fusion power very much. It might even help if Lithium searches are ramped up to help with batteries.

So you need some very small mines. In comparison to the Lithium people will likely already be mining for batteries it will be quite small. Indeed, recycling batteries might be the way to get the lithium for fusion plants.

Re: Rad waste from fusion plants.

The D-T reaction produces a neutron with about 14 MeV. This neutron is troublesome in some ways. It activates nuclei. And it damages the structure of nearly any reactor wall you could imagine. So you wind up producing lots of activated radioactive material. It will not be in a state where a melt down is possible. That is an advantage. But it will be there. And it will be a concern to keep it contained.

As well, you have Tritium. You must have it in order to run the D-T reaction. Which means you expose Lithium to those 14MeV neutrons. Which means you need an extraction plant. Tritium is an isotope of Hydrogen. So you have issues with the stuff leaking. It goes through steel at an annoying rate. And ordinary cement. And a lot of other materials. Some ceramics work ok at retaining it. So a fusion station is going to be a significant source of Tritium as long as it operates, or it is going to be extra expensive because it is built to keep in the Tritium.

 

[Tiger Blood]

Yes tritium is radioactive but it's beta decay. Fortunately, the radioactivity is mild. The electron that is emitted has very low energy, about 19 keV. It cannot penetrate the skin, and even in air can go only 6 mm (1/4 in.) However, it can be harmful if ingested and must be carefully kept out of the water supply. Unlike fission products, tritium has a short half-life of only 12.3 years. This means that 5.47% of it decays into harmless helium each year. Also D-T fusion reactor would generate about 0.1 to 1 percent of the radioactive waste as a nuclear fission reactor producing the same amount of power.

When it comes to lithium if all the world’s energy is generated by fusion, the lithium will last 30 million years.

FUTURE
Like I said earler the deuterium–tritium reaction is a terrible fusion reaction, but we have to start with it because it is easy to ignite. It generates power in neutrons, which make everything radioactive so you cannot go near the reactor. The neutrons are hard to capture and also damage the whole structure of the machine. And you have to breed the tritium and keep it out of the environment. There are much cleaner fusion fuels that we can use in next-generation magnetic bottles.

There are some other reaction like D-He3 has sizeable reactivity at low temperature and produces no neutrons. Unfortunately, you cannot keep deuterium from fusing with itself, so there are DD reactions going on at the same time. But the energy in neutrons is reduced by a factor of 20 relative to DT, and this is an almost clean reaction. The problem is that He3 does not occur naturally. It can, however, be mined on the moon. It is estimated that there are a billion tons of He3 just under the surface of the Moon. Mining machines have been designed which could dig 1 km2 of the moon’s soil, down to 3 m depth, to get 33 kg of He3 a year.
Burning D–He3 on Earth will have to wait until space shuttles can reach the Moon. Nonetheless, the simplicity of the engineering is so attractive that a D–He3 reactor has been designed.

The p-B11 reaction is the most attractive one at present. The reactants are not radioactive, and only helium is produced. Without neutrons, all the shielding and blankets of DT reactors are unnecessary. Fusion power plants can dispense with the tritium recovery and processing plant, as well as with remote handling equipment.
Only hydrogen and boron are used. Boron is plentiful on earth, and B11 is its main isotope. We commonly use 20 Mule Team Borax, a cheap cleanser. All the energy comes out as fast alpha particles. Since these are charged particles, there may be a possibility of direct conversion of the energy into electricity without going through boilers and turbines.

CONVERSION FROM FISSION TO FUSION
Eventually, fission plants will have to be replaced by fusion plants, but only the power core, not the BOP (balance of plant) has to be changed.
Fusion reactors may be expensive, but we will have to pay for them. We can't continue to burn coal or bury nuclear wastes. But building thousands of fusion plants is not as hard as you think. The power core is only a "small" part of the while plant.

 

[DEvens]

The problem with Tritium, as I mentioned, is that it is tough to contain. You need some very special equipment to keep it from leaking right through the container walls. If you try analyzing the naïve "throw the pipes together" sort of model, you will leak just unacceptable amounts of Tritium. "Look at the pretty glow."

Quoting the relative amounts of radioactive waste produced is troublesome since we don't yet have a working design for a fusion power plant.

I don't plan to hold my breath for D-He3 fusion. It would be at least as hard to produce as D-T, maybe harder. And we have not worked out D-T yet.

People talk about p-B11, but I have yet to see a prototype. The people working on this pattern are experiencing exactly the same thing as other fusion researchers: fusion is difficult.

I seriously doubt very many fission plants will be retrofitted with fusion cores. In most cases, the expense of getting the reactor vault to the point where you could do the kind of construction required would exceed any possible savings. By the time you are there you might as well do the full decommission on the site. Also, at least for D-T fusion, the primary-secondary join in the typical fission plant is not going to be acceptable. Among other reasons, because of Tritium. Fission reactors sometimes have difficulty making the limits on Tritium release because of this. Also, it's not clear yet what the final design for a fusion plant will be, so we don't really know if the fusion core will fit. Certainly the core from ITER, with the extra stuff required to operate, get new fuel in, and get heat out, would not fit in the space most reactors are allotted.

 

[Hercuflea]

From wikipedia, the world energy consumption in 2014 was about 100,000 TW*hours = 10^5 * 10^12 = 10^17 Watt*hours .

10^17 W*hours (1 year / 8765.81 hours) * (1 / (1 year)) ~= 10^(-4) * 10^(17) Watts ~= 10^(13) Watts ~= 10 Terawatts of power at any instant.

DEMO is designed to output about 3 GW of combined neutron and alpha particle power, but you can only realistically expect to get maybe 500 MW = 5*10^8 Watts out of that.

So 10^13 Watts / 5x10^8 Watts per reactor means you would need about 20,000 DEMO sized fusion reactors to power the Earth currently. DEMO is only currently in the design stages and is likely to change significantly before it begins construction.

 

[Tiger Blood]

The problem with Tritium, as I mentioned, is that it is tough to contain. You need some very special equipment to keep it from leaking right through the container walls. If you try analyzing the naïve "throw the pipes together" sort of model, you will leak just unacceptable amounts of Tritium. "Look at the pretty glow."

It will have walls around and since tritium is is just another form of hydrogen and can be captured by the carbon to form hydrocarbons. And yeah although techniques for tritium containment are well established in the fission industry, the amount of tritium in fusion is orders of magnitude larger. There has been no experience so far on such a large scale.
But even then do you think that fusion power plants will be more radioactive then oil and coal plants? And we know coal releases fairly large amounts of radioactive thorium and uranium and cause cancer and other problems with coal dust.

<Text removed>

Quoting the relative amounts of radioactive waste produced is troublesome since we don't yet have a working design for a fusion power plant.

Well we know we don't have to rely on splitting the uranium atom, thereby creating energy and a large amount of nuclear waste. Fusion is nature’s way of energizing the universe. We know what by-products of fusion will be: one is helium gas; another is the radioactive steel of the fusion chamber, which eventually has to be buried. It is mildly dangerous only for a few decades.

I don't plan to hold my breath for D-He3 fusion. It would be at least as hard to produce as D-T, maybe harder. And we have not worked out D-T yet.

People talk about p-B11, but I have yet to see a prototype. The people working on this pattern are experiencing exactly the same thing as other fusion researchers: fusion is difficult.

Like you said "fusion is difficult". Many scientists today consider any fusion reaction to be a pipe-dream. If you ask Dr. Pamela Gay she'll tell you it's impossible and if we want cooler planet then we better hope for some strong volcano to spew lots of dust into atmosphere. On the contrast Dr. Brian Cox believes fusion is just around the block and there is nothing scientifically here to stop us from getting it. Now whom to trust? Considering that Dr. Cox is a particle physicist I gather he knows more then Dr. Gay who is only vaguely familiar with nuclear fusion.
Maybe all the people need is serious devotion to the cause. For instance if you watch those movies about Manhattan project you'll see scientists saying "Only few months ago I thought this was impossible." Maybe we need something of what Freddy de Hoffmann said in '50s: "Give me a room full of theoretical physicists and I'll conquer the world."

 

[mheslep]

<text removed>...

http://webcache.googleusercontent.com/search?q=cache:Hi2LP-bwbK8J:www.tricare.mil/tma/congressionalinformation/downloads/Radiation%2520Exposure.pdf+&cd=1&hl=en&ct=clnk&gl=us .

"This letter provides a final report (enclosed), as requested in the Joint Explanatory
Statement accompanying the Consolidated Appropriations Act, 2014, page 90, "Radiation
Exposure," to the congressional defense committees on the number of sailors serving on the
USS RONALD REAGAN during Operation Tomodachi who were potentially exposed to
increased levels of radiation during the humanitarian mission. Our interim report, submitted on
March 27,2014, promised a final report by June 30, 2014.
Some sailors who developed cancer and other serious health conditions allege radiation
exposures while serving on the USS RONALD REAGAN during Operation Tomodachi may be
the cause. There is no objective evidence that the sailors on the USS RONALD REAGAN
during Operation Tomodachi experienced radiation exposures that would result in an increase in
the expected number of radiogenic diseases over time. The estimated radiation doses for all
individuals in the Operation Tomodachi registry, including sailors on the USS RONALD
REAGAN, were very small and well below levels associated with adverse medical conditions. A
detailed explanation of the data collection, methodologies, analyses, and conclusions are
included in the enclosed report"

Please see Non-mainstream theories.
https://www.physicsforums.com/threads/physics-forums-global-guidelines.414380/

 

[Tiger Blood]

OK I really see that people are angry with me because of mentioning USS RONALD REAGAN but I didn't know it was not main-stream for you since I saw those people talking on TV and read it in the places like "The Guardian" who won the Pulitzer prize last year, so why is that non mainstream and in the same bucket with UFOs I don't know.

And also let me just comment some more on this:

I don't plan to hold my breath for D-He3 fusion. It would be at least as hard to produce as D-T, maybe harder. And we have not worked out D-T yet.

People talk about p-B11, but I have yet to see a prototype. The people working on this pattern are experiencing exactly the same thing as other fusion researchers: fusion is difficult.

Well if ITER and DEMO work and we start having nuclear fusion reactors there certainly will be more jobs in the nuclear sector and not to mention new branch of nuclear physics, so more and more people will decide to study nuclear physics then today. Today people are really declining to study natural sciences but rather choose to study economy and management, science is fun to see on internet, but not something serious. So if there are more and more people pursuing careers in nuclear physics there will be more and more people working on it's development. I mean today shows like "The Big Bang Theory" are responsible for slight rise in people pursuing science careers and it's sad that in this day of age people are not interested more, but if there is to be proliferation of nuclear fusion plants all around then it's going to be very motivational for people.

 

[Ryan_m_b]

OK I really see that people are angry with me because of mentioning USS RONALD REAGAN but I didn't know it was not main-stream for you since I saw those people talking on TV and read it in the places like "The Guardian" who won the Pulitzer prize last year, so why is that non mainstream and in the same bucket with UFOs I don't know.

While it's not the same level of nonsense as UFOs news papers exist to sell stories, they have a low credibility in all things science.

Well if ITER and DEMO work and we start having nuclear fusion reactors there certainly will be more jobs in the nuclear sector and not to mention new branch of nuclear physics, so more and more people will decide to study nuclear physics then today.

You seem to have glossed over some of the biggest criticisms in the thread; that these technologies are a long way off. The current timeline for DEMO puts it at generating power in the late 30s/40s. That's a long way away to plan national policy on. In that time we could start significantly rolling out Generation 3+ or even Generation 4 fission stations which produce far less waste and are much safer.

Today people are really declining to study natural sciences but rather choose to study economy and management, science is fun to see on internet, but not something serious.

Which country are you talking about? In the United States adoption of Science and Engineering has risen in recent times. Just look at this graph from the National Student Clearinghouse Research Centre

So if there are more and more people pursuing careers in nuclear physics there will be more and more people working on it's development. I mean today shows like "The Big Bang Theory" are responsible for slight rise in people pursuing science careers and it's sad that in this day of age people are not interested more, but if there is to be proliferation of nuclear fusion plants all around then it's going to be very motivational for people.

I really doubt that show has had more than a negligible effect. Do you know of any studies that have reported it as a determinator for degree choice? Also whilst it's logical that more fusion reactors would create more fusion jobs and could encourage more people to take up the degree we've still got to actually get the fusion research done. That's no guarantee. We could equally invest in fission research which we know could work now.

 

[Stephanus]

CONVERSION FROM FISSION TO FUSION
Eventually, fission plants will have to be replaced by fusion plants, but only the power core, not the BOP (balance of plant) has to be changed.
Fusion reactors may be expensive, but we will have to pay for them. We can't continue to burn coal or bury nuclear wastes. But building thousands of fusion plants is not as hard as you think. The power core is only a "small" part of the while plant.

Yes, a very bright future, I like it. When?

 

[rootone]

We still have not yet produced a fusion reactor that generates more electricity than it consumes ( for more than a few seconds at best).
However, scaled up versions of the almost working designs which exist, MIGHT tip the balance.
Hence the huge immense international effort being invested into the ITER project.
https://en.wikipedia.org/wiki/ITER

If that succeeds in producing an economically useful amount of energy then there will be real incentive to construct similar power plants which could be even more efficient.
It's experimental, though the tokamak design is not new.
We just won't know if it actually will work well enough to seriously compete with fission plants until it's up and running.

 

[nikkkom]

OK I get it. I did a little research and the answer is that there should also be lots of fusion power-plants made but they will be cheap and electricity will be cheap considering that today you don't just pay for electricity bill and pump bill but also devastation of environment, medical bills because they pollute your body and of course war for oil that is costing trillions of dollars. All fusion needs is some sea water which is free and always will be free.

And then the next generation of nuclear fusion reactors will be even more stable and productive.

Even more stable than *what*?

We don't have even one functioning fusion reactor which broke even, *thermal energy wise*, in steady-state operation.

We are even longer way off from a reactor which would produce more *electricity* than it consumes.

We are far, far away from having a fusion reactor which generates electricity anywhere near current electricity prices.

Fusion reactors are not a surefire way forward. Yes, the fuel is plentiful. But fuel is not the only variable at play. Like fission, plant's machinery cost and maintenance costs are likely to dwarf fuel cost.

Some day the inhabitants of this planet will look back at the clumsy magnetic bottle, the D–T tokamak, which will seem like an old IBM Selectric typewriter with font balls compared to Microsoft Word on a 3-GHz notebook computer. The deuterium–tritium reaction is a terrible fusion reaction, but we have to start with it because it is easy to ignite. I mean look how far we made from Wright Brothers to Space Shuttle in just one century or from the first computers till ipads.

Space Shuttle was a failure, BTW. It promised economical access to space. It provided the most expensive one.

Future is notoriously difficult to predict. What you *think* is a best way forward is often not what really turns out to be a best way forward.

At the moment, more solar power gets installed every year than nuclear. And it gets 20% cheaper every 2.5 years.

 

[nikkkom]

Yes, that's true. If I'm not mistaken about 1 in 6500 part of hydrogen in sea water is deuterium. But if somehow we can build a very efficient enrichment deuterium factory, mostly automaton, powered by electricity (which comes from fusion for example) The cost still would not be zero, but it is very low I think.

Re "very low" cost of deuterium. CANDU reactors use heavy water. Each reactor's heavy water inventory costs about one billion dollars.

 

[nikkkom]

Pollution, by definition, is the introduction of a harmful substance into the environment. A properly functioning nuclear plant does not release its waste into the environment and therefore really is zero pollution.

This is not true. Nuclear plants do release radioactivity into environment: seals are not perfect, some fuel pins leak fission gas, etc. Yes, it is negligible compared to natural background, but it's not zero.

And during reprocessing as it is currently done, some tritium and most of Kr-85 are vented to atmosphere.

 

[mheslep]

We don't have even one functioning fusion reactor which broke even, *thermal energy wise*, in steady-state operation.

So far, I'm unaware of any man-made fusion reaction ever producing more energy than induced for *any* amount of time, aside from the explosion of thermo-nuclear weapons. If you know of such a project that has already accomplished even pulsed break-even please share. NIF has not, not counting total energy input.

 

[mheslep]

At the moment, more solar power gets installed every year than nuclear.

I'm skeptical. Apparently the annual installed capacity for solar, at average power (39/6), is almost 7 GW/year, with lifetime ~20 years. I won't attempt here to ascertain how many reactors per year come online, but there are at this moment http://www.world-nuclear.org/info/Facts-and-Figures/World-Nuclear-Power-Reactors-and-Uranium-Requirements/, with lifetime of 40-60 years. And we've not made any calculation of the storage installed to along with the solar, which nuclear does not need.

 

[Tiger Blood]

Which country are you talking about? In the United States adoption of Science and Engineering has risen in recent times. Just look at this graph from the National Student Clearinghouse Research Centre

Yeah I'm talking about US (and other countries are not far). What you didn't watch "Capitalism: A Love Story"?! Here you have to scroll to 1h.02m.30s so that Professor William Black explains it to you

Yes, a very bright future, I like it. When?

Well like I quoted Dr. Francis Chen on page 1 of this topic and he is one of the biggest experts in plasma physics today

"The path is clear, but the rate of progress is limited by financial resources. In the USA, fusion has been ignored by both the public and Congress, mainly because of the lack of information about this highly technical subject. People just do not understand what fusion is and how important it is. Books have been written light-heartedly dismissing fusion as pure fantasy. The fact is that progress on fusion reactors has been steady and spectacular. The 50-year time scale presently planned for the development of fusion power can be shortened by a concerted international effort at a level justified by the magnitude of the problem. It is time to stop spinning our wheels with temporary solutions."

Even more stable than *what*?

That's answered in post #46

And yeah guys you really convinced me that we should all just surrender because fusion is just "too hard" and let us all burn in global warming and pollution. Who knows, as Dr. Pamela Gay said, maybe there will be some volcano spewing lots of dust into atmosphere to shield us (but then once the dust dissipate the sun is back again). We're just too stupid as a species. Let's face it we're just stupid apes who until like yesterday threw each-other feces in faces for fun, maybe we should go back at that!

And for let me end this with quote by Dr. Francis Chen who although is a plasma physicist is obviously too stupid for you:
"Most legislators and journalists have regarded fusion as a pipe dream with very little chance of success. They are misinformed, because times have changed. Achieving fusion energy is difficult, but the progress made in the past two decades has been remarkable. Mother Nature has actually been kind to us, giving us beneficial effects that were totally unexpected. The physics issues are now understood well enough that serious engineering can begin. An Apollo 11-type program can bring fusion online in time to stabilize climate change before it is too late."

 

[Ryan_m_b]

Yeah I'm talking about US (and other countries are not far). What you didn't watch "Capitalism: A Love Story"?! Here you have to scroll to 1h.02m.30s so that Professor William Black explains it to you

I'm actually well aware of the phenomenon of students getting careers outside of STEM, I'm halfway through my PhD and whilst I'm interested in continuing many of my friends just want to get a more stable job with better pay. I'm unaware of any hard statistics though, I just tried looking up some from plenty of sources but mostly it's just anecdotal or news reports. Can you find any stats on this issue? As it's your thread and your point.

Well like I quoted Dr. Francis Chen on page 1 of this topic and he is one of the biggest experts in plasma physics today

"The path is clear, but the rate of progress is limited by financial resources. In the USA, fusion has been ignored by both the public and Congress, mainly because of the lack of information about this highly technical subject. People just do not understand what fusion is and how important it is. Books have been written light-heartedly dismissing fusion as pure fantasy. The fact is that progress on fusion reactors has been steady and spectacular. The 50-year time scale presently planned for the development of fusion power can be shortened by a concerted international effort at a level justified by the magnitude of the problem. It is time to stop spinning our wheels with temporary solutions."

Billions upon billions have been spent on fusion research, it's not exactly poorly funded. The fact that large international projects like ITER exist show that governments are serious about it. The argument of "more can be done" can be applied to any field of science. This isn't really an argument unless there are some detailed experimental proposals that didn't get funded that scientific consensus is would have helped.

That's answered in post #46

And yeah guys you really convinced me that we should all just surrender because fusion is just "too hard" and let us all burn in global warming and pollution. Who knows, as Dr. Pamela Gay said, maybe there will be some volcano spewing lots of dust into atmosphere to shield us (but then once the dust dissipate the sun is back again). We're just too stupid as a species. Let's face it we're just stupid apes who until like yesterday threw each-other feces in faces for fun, maybe we should go back at that!

And for let me end this with quote by Dr. Francis Chen who although is a plasma physicist is obviously too stupid for you:
"Most legislators and journalists have regarded fusion as a pipe dream with very little chance of success. They are misinformed, because times have changed. Achieving fusion energy is difficult, but the progress made in the past two decades has been remarkable. Mother Nature has actually been kind to us, giving us beneficial effects that were totally unexpected. The physics issues are now understood well enough that serious engineering can begin. An Apollo 11-type program can bring fusion online in time to stabilize climate change before it is too late."

Absolutely no one said it was too hard so it's not worth doing. You're lying to yourself if that's what you're taking away from this thread, either that or you enjoy the idea of being the lone dreamer arguing against orthodoxy. An attractive myth but a myth nonetheless. What people have pointed out consistently is that despite billions of dollars in funding and decades of research worldwide viable commercial fusion is still no where in sight. For all we know ITER will reveal new problems that take further decades to solve (it's an experiment after all).

Given that it's much more sensible to continue funding but don't plan on it. Instead we should be lowering our carbon emissions by proven or imminent methods such as: latest generation fission reactors, renewable energy sources and technologies that in conjunction can reduce fossil fuel dependence such as electric transportation.

 

[russ_watters]

Well like I quoted Dr. Francis Chen on page 1 of this topic and he is one of the biggest experts in plasma physics today

"The path is clear, but the rate of progress is limited by financial resources. In the USA, fusion has been ignored by both the public and Congress, mainly because of the lack of information about this highly technical subject. People just do not understand what fusion is and how important it is. Books have been written light-heartedly dismissing fusion as pure fantasy. The fact is that progress on fusion reactors has been steady and spectacular. The 50-year time scale presently planned for the development of fusion power can be shortened by a concerted international effort at a level justified by the magnitude of the problem.

Steady and spectacular compared to what? And isn't that a self-contradiction? Fission research's early progress was spectacular, but way too rapid to be considered "steady". It became technically and commercially nearly instantaneously. In this context, I'd call the "steady" progress of fusion research to be the equivalent of failure.

And yeah guys you really convinced me that we should all just surrender because fusion is just "too hard" and let us all burn in global warming and pollution.

[Mod hat] Please dial back the rhetoric/hyperbole. You are getting dangerously close to putting words in people's mouths they didn't say. Most here have been quite clear that the alternative being advocated is fission, not fossil fuels.

An Apollo 11-type program can bring fusion online in time to stabilize climate change before it is too late."

Maybe - if it works and doesn't take too long. But one thing that is absolutely certain is that any solution to global warming relying on fusion could be implemented faster, cheaper and with a guarantee of success (of getting the plants to function). So we should keep our eye on the ball and attack the problem with the tool that is best for the job.

 

[nikkkom]

And yeah guys you really convinced me that we should all just surrender because fusion is just "too hard" and let us all burn in global warming and pollution.

Acid rains used to destroy entire forests where I live. This no longer happens.

The famous smog of Tokyo is far lass famous now - because it is much better now.

The most noticeable effect of "global warming" to date is not the not-materialized catastrophic sea level rise and resulting flooding, but 30% increase in plant growth.

So there goes "global warming and pollution" bogeyman.

Aside from that, how on Earth do you still manage to ignore the fact that both US and Europe have enough deserts in or nearby them that they can run entirely on photovoltaics, if they'd want to?

 

[Ryan_m_b]

Mod note: this isn't the global warming thread. There is a well established consensus that climate change is a fact and it is a danger. This isn't the site to debate that. This thread is for the discussion of fusion power as a viable means of energy production.

 

[nikkkom]

Mod note: this isn't the global warming thread.

Duly noted. In which case perhaps mods themselves should refrain from discussing it like below?

There is a well established consensus that climate change is a fact and it is a danger.

Interesting that in order to get a consensus, it had to be renamed from "global warming" to "climate change". Anyone with a shred of mathematical education would instantly notice that those aren't the same thing.

Of course "climate change" is real and can be dangerous. Only an idiot who haven't heard about dinosaurs would say that climate never changes, or that it is never dangerous.

 

[Ryan_m_b]

Don't play a semantic game here, I'm sure you're well aware of what I meant. Last polite warning to bring the thread back on topic.

 

[PeterDonis]

The default state of an operational reactor is to continue with fission until positive controlled external action is taken.

Not with the newer designs; those will passively shut down with no issues even with no operator intervention. The Fukushima reactor was designed several decades ago; it is not a good benchmark for evaluating the safety of current designs.

 

[PeterDonis]

how can we speculate about the capacity of a power source that doesn't exist?

I think that's a bit strong. We have built fusion reactors (though we call them "experiments"); we know the reactions involved, we know their rates, we know the general size that a commercial reactor using those reactions would be and how much power it would output. We have plenty of information to make reasonable estimates. In fact we have a lot more information about fusion reactions than scientists had about fission reactions in the 1940's, yet they were able to estimate the capacity of the first generation of controlled fission plants pretty well.

 

[Astronuc]

how can we speculate about the capacity of a power source that doesn't exist?

I think that's a bit strong. We have built fusion reactors (though we call them "experiments"); we know the reactions involved, we know their rates, we know the general size that a commercial reactor using those reactions would be and how much power it would output. We have plenty of information to make reasonable estimates. In fact we have a lot more information about fusion reactions than scientists had about fission reactions in the 1940's, yet they were able to estimate the capacity of the first generation of controlled fission plants pretty well.

From personal experience, I believe Russ's comment is spot on. The first nuclear units were rather small compared to the last completed LWRs, and the current generation being constructed.

Controlled fusion systems for energy generation has proved elusive. Ideally, one could produce substantial energy and use direct energy conversion to obtain about 80% conversion efficiency (minus various radiative losses). In actuality, the thermal efficiency could be much less if a Brayton or Rankine thermodynamic cycle is used - and therein lies the challenge. Can we achieve something like 70-80% conversion, or is it more like 35-42% efficiency.

It all depends on the plant capacity and thermal efficiency as compared to demand.

 

[PeterDonis]

Controlled fusion systems for energy generation has proved elusive.

True, but the reasons have little to do with uncertainty about what the capacity of such systems would be if we could get them to work.

Can we achieve something like 70-80% conversion, or is it more like 35-42% efficiency.

Which means we can estimate capacity within roughly a factor of 2. That's a far cry from not being able to estimate it at all, which was what russ's comment implied.