Uranium Supply Pt 2

[sch_peakoiler]

And how long would it take to convert one LWR to the thorium cycle?

Uranium price is very inflexible. Example: 2003 - seabed level, 2006 - stratosphere.
Lets say it stays at 100 till 2013 and then a part of secondary supplies dries out and say some projected mines are still not there, plus some new LWRs have been built: the price would be instantly at 1000-2000 USD/lb which would have no meaning because there will be physically no uranium to buy.

Then the question will be "how long it takes, how many years you need before thorium reactors run".

[EnergyUnlimited]

And how long would it take to convert one LWR to the thorium cycle?

Uranium price is very inflexible. Example: 2003 - seabed level, 2006 - stratosphere.
Lets say it stays at 100 till 2013 and then a part of secondary supplies dries out and say some projected mines are still not there, plus some new LWRs have been built: the price would be instantly at 1000-2000 USD/lb which would have no meaning because there will be physically no uranium to buy.

Then the question will be "how long it takes, how many years you need before thorium reactors run".

I think, you should direct this particular question (in form of PM perhaps) to Tanada, who knows some details about experimental conversion run in one of US reactors.

My guess is that conversion of PWR into thorium cycle would take about 1 year of engineering work.
Breeding factor in thorium cycle was experimentally shown to be about 1.01.
It is reasonable to expect that we could increase it to 1.02 perhaps.

1% excess of fissile material over amount of used one would allow you to secure enough of U233 to set up additional reactor working after about 70 years of work of original one.

You could circumvent this difficulty to some extend by "igniting" additional thorium cycle reactors with HEU (weapon grade uranium 235) diluted to about 5% with thorium-232.
Such a fuel would have to be treated with care.
If stolen, it could be converted to weapon material with primitive measures only.

Perhaps better alternative here would be to ignite thorium cycle by mixing thorium with few% of reactor grade plutonium, which is more difficult (but still possible) to divert for weapon use.

I have red few articles suggesting diluting thorium with U238, just to prevent possibility of easy diversion of fissile materials to weapons use.
Anyone who might attempt diversion would end up with necessity of separation of uranium isotopes - difficult process which cannot be concealed easily and requiring reasonably developed technology.
However breeding factor in such a setup is always below 1, so this approach is a dead end in long run.

[sch_peakoiler]

So effectively this means thorium is a no-runner in the next 20 years for sure, if we started yesterday (just because you can not breed enough of it).

[EnergyUnlimited]

So effectively this means thorium is a no-runner in the next 20 years for sure, if we started yesterday (just because you can not breed enough of it).

You are actually breeding U233, not thorium.

You could divert some high grade plutonium or HEU from atomic weapons, just to set up new thorium based reactors.

I am also suspecting that many PWR-s are going to be converted into thorium cycle once uranium is no longer available in required quantities.

[sch_peakoiler]

So effectively this means thorium is a no-runner in the next 20 years for sure, if we started yesterday (just because you can not breed enough of it).

You are actually breeding U233, not thorium.

You could divert some high grade plutonium or HEU from atomic weapons, just to set up new thorium based reactors.

I am also suspecting that many PWR-s are going to be converted into thorium cycle once uranium is no longer available in required quantities.

Yeah I know what you breed.
The question is how much HEU or Weapon-PU one needs convert say 100 PWR reactors? If at some time in the future we do not have enough LEU to run them normally where will we get enough HEU to "ignite" them in thorium cycle?

[EnergyUnlimited]

So effectively this means thorium is a no-runner in the next 20 years for sure, if we started yesterday (just because you can not breed enough of it).

You are actually breeding U233, not thorium.

You could divert some high grade plutonium or HEU from atomic weapons, just to set up new thorium based reactors.

I am also suspecting that many PWR-s are going to be converted into thorium cycle once uranium is no longer available in required quantities.

Yeah I know what you breed.
The question is how much HEU or Weapon-PU one needs convert say 100 PWR reactors? If at some time in the future we do not have enough LEU to run them normally where will we get enough HEU to "ignite" them in thorium cycle?

Assuming that you need annual load 200 tons of 4% uranium 235 for running 1GW PWR, this makes 8 tons of fissile isotope.

My guess with error not exceeding 50% is that you would roughly need 4 tons of HEU, or reactor grade plutonium or weapon grade plutonium for ignition of single thorium breeder.
You could use anyone of these.

[sch_peakoiler]

And how long should a thorium breeder run on HEU till it has bred enough U233 to start a normal cycle? about 10 years I guess? Lets take 10 years as a base.

so we take 100 PWRs, 400 tons of HEU, a bunch of thorium and start the cycle.
after 10 years we are able to refill them with Th+U233, and then they will breed at optimistic 1.02, so that we have another "fuel refill" after some 35 years. effectively 200 reactors after 35 years.

so we have

X years - conversion of 100 reactors
10 years - ignition of 100 reactors
35 years - 200 reactors
35 years - 400 reactors (close to what we have now)
35 years - 800 reactors...
etcetera

Tanada, Dezakin : where is the error?

you know what: this back of the envelope calculation tells us that we can forget breeders. we need more than 100 years to make them run "in an amount larger than what we have now.
We can only use breeders if the cycle were started as long as we use normal nuclear cycle. But as you say we will first wait for 400 USD/lb, which means another couple years....

Well: forget breeders completely and stick with SWU, old tails, MOX, Mining, PWR :)

[EnergyUnlimited]

And how long should a thorium breeder run on HEU till it has bred enough U233 to start a normal cycle? about 10 years I guess? Lets take 10 years as a base.

This I think is unimportant. After next and next round of reprocessing U233 will be greater and greater part of total fissile isotope at work.

so we take 100 PWRs, 400 tons of HEU, a bunch of thorium and start the cycle.
after 10 years we are able to refill them with Th+U233, and then they will breed at optimistic 1.02, so that we have another "fuel refill" after some 35 years. effectively 200 reactors after 35 years.

so we have

X years - conversion of 100 reactors
10 years - ignition of 100 reactors
35 years - 200 reactors
35 years - 400 reactors (close to what we have now)
35 years - 800 reactors...
etcetera

Tanada, Dezakin : where is the error?

you know what: this back of the envelope calculation tells us that we can forget breeders. we need more than 100 years to make them run "in an amount larger than what we have now.
We can only use breeders if the cycle were started as long as we use normal nuclear cycle. But as you say we will first wait for 400 USD/lb, which means another couple years....

Well: forget breeders completely and stick with SWU, old tails, MOX, Mining, PWR :)

I think, you are still a victim of exponential growth paradigm.

Well, if you wish to plan for a long term future, you should forget about perpetual growth.
So you may have to accept perhaps 800 thorium breeder reactors within 100 or may be even 200 years from now on but yet keep this number working for ever, or close to that.

The only alternative is that you will end up with no reactors at all, once you cannot satisfy U235 demand.

Nuclear energy is not a magic bullet, which allows you to carry on with status quo for ever.
However, if developed in thoughtful fashion, it can provide reliable baseload of electricity supply amounting to about 20-30% of current consumption level for millennia perhaps.

However the sad truth is that we are likely to apply it in a silly, shortsighted fashion, building some more LWR-s and gradually running out of uranium supply within 60 or 100 years from now on.
First substantial shakes within industry are likely to be seen within decade from now on, when excess of HEU runs out.

[sch_peakoiler]

I think, you are still a victim of exponential growth paradigm.

I think you just do not understand what I am doing. But thats Ok. My questions just do not seem to make a system, do they? they do.
I want to quantify the basics of nuclear energy. thats it. Tanada started a FISSION FAQ here. But he explained isotope basics and then had enough of this - the FAQ is unfinished big time. So there are no numbers connecting WHEN with HOW MUCH on nuclear power. Only the assurance of Dezakin that we have enough uranium in the crust and can scale up the mining to any scale needed.
So if anybody says: then we will go thorium and this is an endless supply, I want to know WHEN and HOW MUCH. just for me. To understand the basics.

[Tanada]

And how long should a thorium breeder run on HEU till it has bred enough U233 to start a normal cycle? about 10 years I guess? Lets take 10 years as a base.

so we take 100 PWRs, 400 tons of HEU, a bunch of thorium and start the cycle.
after 10 years we are able to refill them with Th+U233, and then they will breed at optimistic 1.02, so that we have another "fuel refill" after some 35 years. effectively 200 reactors after 35 years.

so we have

X years - conversion of 100 reactors
10 years - ignition of 100 reactors
35 years - 200 reactors
35 years - 400 reactors (close to what we have now)
35 years - 800 reactors...
etcetera

Tanada, Dezakin : where is the error?

you know what: this back of the envelope calculation tells us that we can forget breeders. we need more than 100 years to make them run "in an amount larger than what we have now.
We can only use breeders if the cycle were started as long as we use normal nuclear cycle. But as you say we will first wait for 400 USD/lb, which means another couple years....

Well: forget breeders completely and stick with SWU, old tails, MOX, Mining, PWR :)

Seems how you asked I will answer. You can assemble a LWBR in roughly a year. This is done by rearranging the fuel elements and controll rods. A LWBR along the lines of the Shippingport project consists of positive controll rods as opposed to the regular negative controll rods used in a standard reactor. Where a negative controll rod works by absorbing neutrons and slowing or stopping the reaction a positive controll rod does the exact opposite by inserting moderatly higher enriched fuel (circa 6% fissionable) that add neutrons to the reaction and speed it up. The negative controll rods are still availible for emergency use, but under nearly all scenarioa extracting the positive controll rods causes the reaction to slow down and stop without them.

To convert any regular PWR to LWBR operation you need Thorium plus a fissionable material. The majority of the rods in the core would be 97% to 98.5% Thorium and 2.5% to 3% U-235 and the positive controll rods 94% Thorium and 6% U-235. Note that you can substitute U-233 or Pu-239 or Reactor Grade Plutonium for the U-235 in the first load.

Now once you have your first fuel load in the reactor you start out with the positive controll rods fully extracted. You then extract the negative controll rods. At this point the reactor is still off, there is not enough reactivity present to start and sustain a fission chain reaction. You then very slowly insert some of the positive controll rods until you acheive unity, where each fission of one atom leads to the fission of another atom and the reactor is critical.

For the next 10 years based on the shippingport experimental proof of concept the reactor continues to operate generating heat which is used to produce electricity without stopping to refuel.

After 10 years you withdraw all of the fuel and put it in a cooling pool, replacing it with a fresh load. For the next 10 years the second core will power the reactor without needing to be refueled.

9 years after you extract the first core it is cool enough that you can either reprocess it to recover the Thorium, Uranium and Plutonium or put it in dry cask storage for long term safe storage. If you choose to reprocess the fuel you remove the 7% to 10% of fission products, add 7% to 10% fresh Thorium to replace the fission products and reassemble the fuel into rods with 2.5% U-233/U-235/Plutonium and 97.5% Thorium for most of the core and 6% U-233/U-235/Plutonium and 94% Thorium for the positive controll rods. Because of the near unity breeding ratio all of the fissionable materials in the new fuel are captured during the reprocessing, the tiny amount left over can be used as additional fuel for other reactors or stored for later use.

With a LWBR you only ever need enough fissionable material to manufacture two cores up front, one to operate the reactor for 10 years and one to cool for 9 years before being reprocessed and remanufactured for use while the other core is in the cooling cycle.

LWBR do need Thorium feedstock to replace the fission fragments removed during reprocessing which amount to around 7% to 10% of the total fuel mass for the core. Because Thorium is three times as abundant as Uranium and about 50% better at capturing thermal neutrons than U-238 it will breed U-233 just fast enough in the LWBR configuration to replace used up fissionable materials.

[Tanada]

And how long should a thorium breeder run on HEU till it has bred enough U233 to start a normal cycle? about 10 years I guess? Lets take 10 years as a base.

so we take 100 PWRs, 400 tons of HEU, a bunch of thorium and start the cycle.
after 10 years we are able to refill them with Th+U233, and then they will breed at optimistic 1.02, so that we have another "fuel refill" after some 35 years. effectively 200 reactors after 35 years.

so we have

X years - conversion of 100 reactors
10 years - ignition of 100 reactors
35 years - 200 reactors
35 years - 400 reactors (close to what we have now)
35 years - 800 reactors...
etcetera

Tanada, Dezakin : where is the error?

you know what: this back of the envelope calculation tells us that we can forget breeders. we need more than 100 years to make them run "in an amount larger than what we have now.
We can only use breeders if the cycle were started as long as we use normal nuclear cycle. But as you say we will first wait for 400 USD/lb, which means another couple years....

Well: forget breeders completely and stick with SWU, old tails, MOX, Mining, PWR :)

Oh and one more thing, the initial fuel load of highly enriched U-235 uses up about as much natural Uranium as two regular PWR cores would use, but because of the fertility of Thorium it lasts three times as long in the reactor. It is also the last natural Uranium you need to consume once the LWBR is up and running on its first recycled core. Alternatley you can use reactor grade Plutonium for the first two cores and you can get that plutonium from reprocessing roughly six spent fuel cores for each load. The USA alone has about 700 spent cores in storage that would provide enough reactor grade plutonium to start up 120 LWBR. It would take about a year to convert a PWR to LWBR and the USA has about 68 PWR's in operation today so reprocessing the spent fuel currently in storage would provide the two initial cores of PU/TH for LWBR for 60 of them.

The BWR reactors are not well suited for conversion to LWBR due to the differences in their core design, they would need to keep operating on enriched Uranium or MOX. Alternatively the BWR's can be operated on TMOX-RG (Thorium Mixed Oxide Reactor Grade Plutonium fuel) or Thorium/Uranium fuel, however because of the core design they will not be able to acheive breeding, instead they would be high efficiency convertor reactors operating in the .9 region instead of 1.01 like the LWBR's would.

[Dezakin]

And how long should a thorium breeder run on HEU till it has bred enough U233 to start a normal cycle? about 10 years I guess? Lets take 10 years as a base.

This I think is unimportant. After next and next round of reprocessing U233 will be greater and greater part of total fissile isotope at work.

so we take 100 PWRs, 400 tons of HEU, a bunch of thorium and start the cycle.
after 10 years we are able to refill them with Th+U233, and then they will breed at optimistic 1.02, so that we have another "fuel refill" after some 35 years. effectively 200 reactors after 35 years.

so we have

X years - conversion of 100 reactors
10 years - ignition of 100 reactors
35 years - 200 reactors
35 years - 400 reactors (close to what we have now)
35 years - 800 reactors...
etcetera

Tanada, Dezakin : where is the error?

you know what: this back of the envelope calculation tells us that we can forget breeders. we need more than 100 years to make them run "in an amount larger than what we have now.
We can only use breeders if the cycle were started as long as we use normal nuclear cycle. But as you say we will first wait for 400 USD/lb, which means another couple years....

Well: forget breeders completely and stick with SWU, old tails, MOX, Mining, PWR :)

I think, you are still a victim of exponential growth paradigm.

Well, if you wish to plan for a long term future, you should forget about perpetual growth.
So you may have to accept perhaps 800 thorium breeder reactors within 100 or may be even 200 years from now on but yet keep this number working for ever, or close to that.

The only alternative is that you will end up with no reactors at all, once you cannot satisfy U235 demand.

Nuclear energy is not a magic bullet, which allows you to carry on with status quo for ever.

Well, it sort of is... just not growth forever. With thorium breeders you can utilize a fuel 3 times as plentiful 200 times more efficiently (in addition to uranium) multiplying your base reserves by 800 and opening up the lowest grade resources... basic crust has an energy density 30 times that of coal burned in thorium breeders.

Now the problem with burning the 160 trillion tons of uranium and thorium in the crust in growth isn't running out of fuel, with a 1GW reactor demanding some 1 ton per year... its running out of heat dissipation capacity of the earth. If you make as much energy as the sun (say 10^16 watts?) you become dangerously close to altering the global climate without doing anything to the atmosphere at all, and your fuel resource will only last 16 million years.

I dont think we're going to do that with nuclear reactors, partially because I expect solar will eventually become more economical and much of human industry will be space based, but its an interesting exercise.

[EnergyUnlimited]

Now the problem with burning the 160 trillion tons of uranium and thorium in the crust in growth isn't running out of fuel, with a 1GW reactor demanding some 1 ton per year... its running out of heat dissipation capacity of the earth. If you make as much energy as the sun (say 10^16 watts?) you become dangerously close to altering the global climate without doing anything to the atmosphere at all, and your fuel resource will only last 16 million years.

You don't have to worry about these.
You will not be able to construct necessary infrastructure to utilize even small proportion of available total.

I dont think we're going to do that with nuclear reactors, partially because I expect solar will eventually become more economical and much of human industry will be space based, but its an interesting exercise.

I don't think we are going to develop solar sufficiently to cover even current level of use but there is a small chance that few percent of current consumption will be covered by that.

Nuclear will in all probabilities be used for several decades more, then uranium 235 will no longer be economical to use, MOX will run out and reactors will shut down.
Maybe several thorium breeders will be built to carry on here and there, but this is still open question.

At this time we are unlikely to see much industry left, either on Earth or in space.
Perhaps there will be some industry somewhere in space, as long as it is run by Aliens.

[Dezakin]

And how long should a thorium breeder run on HEU till it has bred enough U233 to start a normal cycle? about 10 years I guess? Lets take 10 years as a base.

so we take 100 PWRs, 400 tons of HEU, a bunch of thorium and start the cycle.
after 10 years we are able to refill them with Th+U233, and then they will breed at optimistic 1.02, so that we have another "fuel refill" after some 35 years. effectively 200 reactors after 35 years.

Theres no way PWRs are going to breed at 1.02. The core geometry is wrong, LWR eats too many neutrons and isn't an optimal moderator. There was a light water breeder reactor designed but IIRC it wasn't like the PWRs on the market.

If I had access to say 400 billion dollars instead of invading some country I'd probably spend say 10 on the development of a molten chloride fast reactor for incinerating the plutonium and other actinides in spent fuel, and another 10 on the development of a molten fluoride reactor for meeting the global energy demands, and then spend I'd guess 2 billion each on the chloride fast reactors and about 1.5 billion on the fluoride thermal reactors.

The molten chloride incinerator reactors could run entirely on spent fuel plutonium, and we've got some 50 years of that stuff stockpiled up that we can send the uranium back to the enrichment plants for reintroduction into the market of PWRs (just basic fluoride volitility or using ANL pyroprocessing, so should be cheaper than the aqueous reprocessing methods for MOX fuel. No fuel fabrication requirement makes this cheaper also) The chloride reactors have a breeding ratio of over 1.4 IIRC (better than even LMFBR because of the xenon purging) and all the extra neutrons can go to the thorium blanket which continually strips out the U233 for marketing for the liquid flouride reactors.

The liquid flouride reactors have a breeding ratio of about 1.05, and as such really are converter reactors. They would cost less after development than a comperable PWR because of lower capital costs (running at atmospheric pressure negates the need of massive pressure vessels that can only be built by two steel foundries on the planet for a start, as well as having higher power density, smaller cores and higher thermodynamic efficiency) lower operating costs (no fuel fabrication requirement, much cheaper fuel costs, continuous revenue stream from marketable fission products like platinum metals, xenon, and radioisotopes.)

Also this would finally get people to shut up about the whole running out of energy meme when they realize how much energy is recoverable just by digging up some dirt in the backyard. (Cue in next doomy topic about overpopulation, ecological collapse, whatever. Theres allways some pessimistic horizon)

Strictly speaking, the chloride fast reactor is unnecissary. Fluoride thermal breeders can be started on enriched uranium, and the only industry demand would be for the initial fuel load. The chloride reactors are only aesthetically desirable for incineration of the spent fuel stockpile and optimal production of U233 for the market.

The fluoride reactors would consume 1/200th of a fuel thats 3 times as plentiful, produce 1/1000th of the waste that would have an average of a 30 year half life so that in 300 years the stuff is less radioactive than the ore it came from.

Well: forget breeders completely and stick with SWU, old tails, MOX, Mining, PWR :)

That, IMHO, is sufficient for the fuel cycle and energy demands of civilization, though not aesthetically pleasing or optimally efficient. I doubt things will play out with any breeder reactors in the future because of the initial startup risk, unless some government decides they're making a strategic decision for energy security.

[EnergyUnlimited]

If I had access to say 400 billion dollars instead of invading some country I'd probably spend say 10 on the development of a molten chloride fast reactor for incinerating the plutonium and other actinides in spent fuel, and another 10 on the development of a molten fluoride reactor for meeting the global energy demands, and then spend I'd guess 2 billion each on the chloride fast reactors and about 1.5 billion on the fluoride thermal reactors.

If one take into account current FED monetary policy, there is a good chance that within next several years $ 400 billion will buy you a box of matches

Anyway, $10 billion for existing business or governments is not very much.
My suspicion is that no significant work is done on molten salt breeders, because it is already concluded that these will not work economically if applied in power plants.

[Dezakin]

I think, you are still a victim of exponential growth paradigm.

I think you just do not understand what I am doing. But thats Ok. My questions just do not seem to make a system, do they? they do.
I want to quantify the basics of nuclear energy. thats it. Tanada started a FISSION FAQ here. But he explained isotope basics and then had enough of this - the FAQ is unfinished big time. So there are no numbers connecting WHEN with HOW MUCH on nuclear power. Only the assurance of Dezakin that we have enough uranium in the crust and can scale up the mining to any scale needed.
So if anybody says: then we will go thorium and this is an endless supply, I want to know WHEN and HOW MUCH. just for me. To understand the basics.

I cant quantify what economics will do, or weather people will all decide that investing in panda fur purses are a better bet than uranium mines in a tight market. All we can really point to here is production numbers of mines open today, previous growth rates during demand acceleration (which I believe was substantial based on the growth of the nuclear power industry) and the energy requirements of mining. We can easily state that uranium is very energy positive in any time regime in the next several millinia because the Rossing mine data is very clear.

1 unit of energy in mining 300ppm ore from Rossing mine yields enough uranium to make 500 units of electric energy in light water reactors. With the rather crude, but reasonable estimate that energy demands of mining are inversely proportional to the ore grade, we can exploit some 1 trillion tons of uranium at an energy gain of 15-30, more than some large petrochemical projects, and thats enough to last 20000 light water reactors 250000 years. This is simple arithmetic and I have very high confidence in this.

The mine production numbers for this year, next year, next decade, I couldn't say. I'd guess that the market should respond, but maybe it wont and capital will flow towards something else, or some other political problem will get in the way, and we can argue all day about weather mines will produce x% more uranium to meet market demand. I think they will because people stand to make a lot of money if they do, but sure, they might not for a host of above ground issues seperate from engineering and energy.

But this doesnt detract from uranium having the capacity to be a resource into the distant future.

[Dezakin]

If I had access to say 400 billion dollars instead of invading some country I'd probably spend say 10 on the development of a molten chloride fast reactor for incinerating the plutonium and other actinides in spent fuel, and another 10 on the development of a molten fluoride reactor for meeting the global energy demands, and then spend I'd guess 2 billion each on the chloride fast reactors and about 1.5 billion on the fluoride thermal reactors.

If one take into account current FED monetary policy, there is a good chance that within next several years $ 400 billion will buy you a box of matches

Take it to economics forum, I dont care to argue religeon.

Anyway, $10 billion for existing business or governments is not very much.
My suspicion is that no significant work is done on molten salt breeders, because it is already concluded that these will not work economically if applied in power plants.

Nope. The reason the plug was pulled in the early 70's was because molten salts had a poor breeding ratio compared to liquid metal reactors were much more amenable to breeding plutonium.

Molten salt reactors have a much better chance of economic power production than any other breeding regime simply because it internalizes the reprocessing cost and gets rid of fuel fabrication regimes. I've seen economic analysis on molten salt reactors that show them to produce power at a lower cost than PWRs or even coal.

http://thoriumenergy.blogspot.com/

[sch_peakoiler]

Theres no way PWRs are going to breed at 1.02.

the number 1.01 comes from Tanada, the number 1.02 from EnergyUnlimited. Can you please agree with them on anything?
because it is difficult to discuss if the proponents do not agree on one number.

Also this would finally get people to shut up about the whole running out of energy meme when they realize how much energy is recoverable just by digging up some dirt in the backyard. (Cue in next doomy topic about overpopulation, ecological collapse, whatever. Theres allways some pessimistic horizon)

Yeah you have drawn a techno paradise. Looks nice. Pity that in the capitalism technolgy is suppressed by big financial interests "intertwined" with politics I would also support a world with large scale nuclear research and development. Because now it is stagnating... One working Fast Breeder and one being built. and this not even in a country calling itself GREAT 7. anyway.

as you correctly point out, as things are now - people tend NOT to shut up about the whole energy thing. They want facts and dont let anybody feed them with expectations.

Strictly speaking, the chloride fast reactor is unnecissary. Fluoride thermal breeders can be started on enriched uranium, and the only industry demand would be for the initial fuel load. The chloride reactors are only aesthetically desirable for incineration of the spent fuel stockpile and optimal production of U233 for the market.

As far as I get the situation, if we manage to breed and burn U238 and Th232 we will get a pretty long term supply, which would surpass thousands of years. If. We. Manage.

That, IMHO, is sufficient for the fuel cycle and energy demands of civilization

MHO is slightly different on this. I think that we still have to see some more progress on mining U from leaner ores.

, though not aesthetically pleasing or optimally efficient. I doubt things will play out with any breeder reactors in the future

I agree...

[sch_peakoiler]

energy positive in any time regime in the next several millinia because the Rossing mine data is very clear.

I understand this. Things I do not understand completely are:

how much discovered (not estimated) uranium do we have at 300 ppm?

would we possibly get a problem of scale trying to replace high grade mines which are bound to run out with low grade mines and trying to expand production at the same time?

The mine production numbers for this year, next year, next decade, I couldn't say.

you cannot. but the industry can do that,does that and fails. Thats the problem. you are not responsible for what is being said. Dont feel like I am attacking you.

[sch_peakoiler]

double post, deleted.