Uranium Supply Pt 2

[pstarr]

so if uranium energy is used up mining uranium you would still mine it?

[EnergyUnlimited]

so if uranium energy is used up mining uranium you would still mine it?

There is enough of energy in uranium to mine "replacement", deal with waste and to provide some excess into grid.

[pstarr]

so if uranium energy is used up mining uranium you would still mine it?

There is enough of energy in uranium to mine "replacement", deal with waste and to provide some excess into grid.

what replacement? and how do we know there is enough energy to deal with waste? we haven't done it yet, have we?

[EnergyUnlimited]

so if uranium energy is used up mining uranium you would still mine it?

There is enough of energy in uranium to mine "replacement", deal with waste and to provide some excess into grid.

what replacement? and how do we know there is enough energy to deal with waste? we haven't done it yet, have we?

Replacement means additional mined uranium to replace spent fuel.
You can also mine thorium, which is capable to give ca 100 times more energy, than uranium can (I assume here that FBR had failed, but this is still an open question).

The best approach in dealing with waste is to reprocess it to recover uranium, plutonium and other actinides.
Remainig waste is not such a great problem anymore and all, what you have to do is to burry it in suitable depository area, fingers cross and hope for the best. One or two thousands years and it is gone (with exception of technetium perhaps, but this one is of low radiotoxicity only).
However if you neglect reprocessing, than you are in bigger trouble.
Pu 239 has 24000 years half life and here your trouble begins.

[sch_peakoiler]

pstarr,

it is a very interesting question about the EROI of Uranium mining. Stormsmith report (this is a "codename" for that Van Whatever - sorry cannot memorize the spelling of the name - report) - says that Ores of certain grade have EROI less than 1. Certain grade in this case means under 0.05%, which is about the lowest mark of the grade we mine today. So in Stormsmith's opinion - what we have now explored - are the last tons of uranium we can mine EROI positive.

I am very interested in this subject, because this is the area where opinions of proponents differ from the opinions of the opponents in tens(sic!!!!!) orders of magnitude (sic!!!!!!). Compared to this, other discussions have a 100% consent and agreement!!!!
Opponents say - 40 years supply, current consumption.
Proponents say - billions of years of supply, current consumption.

This means, something is fishy:)

I analyzed Stormsmith's report myself, apart from reading the official rebuttals, and their answer, AND the rebuttal of the answer.

I came to a conclusion that the whole report is built on a specific yield to ore grade function, which was extrapolated from theory. There were no practical data at the moment of writing the report for low quality ores. So Stormsmith report forecasts the yield to behave in a specific way, and thus gets its results.
Should the yield to grade function be proven wrong, the whole report will be proven wrong, disregarding the energy input they estimate for mining and milling.

Their formula looks roughly like this. E is energy consumption

E = Emine/yield(grade) + Emill + Eenrich;

It simple maths than shows us that the last two components are constant and do not play a substantial role. Yield (grade) is, on the other hand, important.

Practical data, obtained after the report was published, showed that this estimated yield (grade) function made a wrong prediction for a Namibia Rossing mine. So far it was the only example, as not so many mines have been explored with a rather low ore quality.

So far, Stormsmith was only wrong. As we see more mines coming online we will see of course more evidence for either part, so just we wait:):)

pstarr,
What is your opinion about the possible EROI of uranium?

[sch_peakoiler]

EnergyUnlimited,

I guess I asked you a question some pages afore, which you did not see yet. It was an answer on your post about uranium EROI, of 20 ppm, whether it is positive or not.

[Ludi]

There is currently no long-term storage for nuke wastes, all current storage is temporary. There are currently no facilities operational for long term storage in the US.

"Current storage methods shield any harmful radiation and are presently safe. However, modern aboveground storage structures are designed for temporary storage only, and will not withstand rain, wind, and other environmental factors for the tens of thousands of years during which the waste will be hazardous."

http://www.ocrwm.doe.gov/factsheets/doeymp0338.shtml

[EnergyUnlimited]

I am very interested in this subject, because this is the area where opinions of proponents differ from the opinions of the opponents in tens(sic!!!!!) orders of magnitude (sic!!!!!!). Compared to this, other discussions have a 100% consent and agreement!!!!
Opponents say - 40 years supply, current consumption.
Proponents say - billions of years of supply, current consumption.

I claim ca. 10 000 years of uranium AND thorium supply.
I see thorium to be critical for long term future of nuclear power.
I believe, that something like 1000-2000 (but no more than that) of electricity producing nuclear reactors could be runned on Earth in "sustainable" fashion. They will not replace traditional transport fuel (with exception of rail and large scale sea transport perhaps), but neverthless they can secure "civilization continuity".
They will certainly fail, if applied to keep running American Dream.

It is possible (but by no means certain), that we will at some point learn how to recover EROEI>1 uranium from sea water (~3mg of uranium per cubic metre) and secure by the same virtually unlimited supply of uranium, but I would rather consider this route to be interesting way of tapping wave power.

[EnergyUnlimited]

EnergyUnlimited,

I guess I asked you a question some pages afore, which you did not see yet. It was an answer on your post about uranium EROI, of 20 ppm, whether it is positive or not.

I do not consider 20ppm uranium to be of sufficient EROEI to be worth bothering with, unless it is recovered as by-product from other process like phosphate fertilizer manufacturing.
I consider something like 50ppm to be cut off.
This is all based on premise of FBR failure, but FBR are still an open question.

Those assertions are irrelevant in respect to sea water.
You do not have to mill it after all, and completely different technology (based on ion exchangers) is investigated there.
It may or may not be successful.

[EnergyUnlimited]

There is currently no long-term storage for nuke wastes, all current storage is temporary. There are currently no facilities operational for long term storage in the US.

"Current storage methods shield any harmful radiation and are presently safe. However, modern aboveground storage structures are designed for temporary storage only, and will not withstand rain, wind, and other environmental factors for the tens of thousands of years during which the waste will be hazardous."

http://www.ocrwm.doe.gov/factsheets/doeymp0338.shtml

Long term issues measured in tens of thousands of years are only relevant, if you are refusing to do reprocessing.
United States are in opposition to reprocessing (to help themself with hegemony doctrine, I guess, NK may assist them in abandoning of this doctrine anyway) therefore they are heading for long term problems. Their choice.
Some more clever nations (like Brits ) are happy with reprocessing of spent fuel, therefore waste storage will be far easier to deal with.
Shortly, waste and other safety issues in nuclear sector are rather of political and PR than engineering nature.

[sch_peakoiler]

EnergyUnlimited,

I see your point. So you see, you fall between radical opponents and radical proponents:) Because radical proponents see FBRs as already built and tested at any scale, ready to run tomorrow morning, breeding at 10x, spewing pu239 like crazy and giving out millions of billions of TWh(e) per SECOND in the mean time Ok, that was a really radical one:):)

Jokes apart, I think a very important issue is this OPEN QUESTION issue thing. You mention FBRs as open. I would say Thorium is an open issue as well, as it means breeding, and we have not been really successfull in breeding (except for breeding ourselves or cattle) for some time now. How many operating Thorium nuclear plants you know in the world?

Nuclear opponents, however, use this argumentation: We do not produce electricity with FBRs nor we do it with Thorium. The only technologies which are used and are planned on are LWR+MOX+a little bit of CANDU. So lets only discuss LWRs.
This kind of argumentation is of course not very satisfactory, but in general, the absence of practically employed hi-tech solutions gives the opponents their argument.

I for myself, after analyzing data from the both sides came to the conclusion that we can mine ores with 20 ppm, but if we continue building LWRs, than it would be logistically too difficult to do. And we, which is pity of course, continue to build LWRs

[Dezakin]

so if uranium energy is used up mining uranium you would still mine it?

There is enough of energy in uranium to mine "replacement", deal with waste and to provide some excess into grid.

what replacement? and how do we know there is enough energy to deal with waste? we haven't done it yet, have we?

Replacement means additional mined uranium to replace spent fuel.
You can also mine thorium, which is capable to give ca 100 times more energy, than uranium can (I assume here that FBR had failed, but this is still an open question).

You dont have to use fast reactors to utilize U238. You can do molten salt breeders that combine Th232 and U238. The chemistry is a bit more challenging because of the higher ratio of transuranic actinides, and ideally you probably have a four fluid reactor.

The best approach in dealing with waste is to reprocess it to recover uranium, plutonium and other actinides.

I sort of think the best approach to dealing with waste is to stick it in dry storage casks until demand for spent fuel makes it economically viable to reprocess. Then crack it open and stick it in the reactors. Lots of nice fission platenoids that command high market value also.

[Dezakin]

EnergyUnlimited,
Jokes apart, I think a very important issue is this OPEN QUESTION issue thing. You mention FBRs as open. I would say Thorium is an open issue as well, as it means breeding, and we have not been really successfull in breeding (except for breeding ourselves or cattle) for some time now. How many operating Thorium nuclear plants you know in the world?

Theres no point in running a breeder reactor until the economics are more favorable than LWR reactors. The only breeder reactor that has a hope of being competitive with LWR is the molten salt breeder reactor, because it has a more scalable design (tens of megawatts to gigawatts) and avoids the fuel fabrication logistical problems.

There was a molten salt reactor that ran for several years at ORNL as a successful demonstrator. Current logistical problems include swelling of the moderator do to neutron erosion, so the moderator must be replaced somewhat regularly in the ORNL design, but its not implausible to imagine a MSBR that runs without a moderator in the epithermal spectrum.

Nuclear opponents, however, use this argumentation: We do not produce electricity with FBRs nor we do it with Thorium. The only technologies which are used and are planned on are LWR+MOX+a little bit of CANDU. So lets only discuss LWRs.
This kind of argumentation is of course not very satisfactory, but in general, the absence of practically employed hi-tech solutions gives the opponents their argument.

I'm fine using only those arguments, given the ore yield data. Then we go from several billion years to several thousand, and a lot can happen in several thousand years.

I for myself, after analyzing data from the both sides came to the conclusion that we can mine ores with 20 ppm, but if we continue building LWRs, than it would be logistically too difficult to do. And we, which is pity of course, continue to build LWRs

I dont think its really that big of an issue. It will be hundreds of years before we are forced to use such poor ore grades using only the once through LWR, and by then one might reasonably imagine we'll either use more advanced breeder reactors or actually get some alternative energy technology to the point of economic competitiveness. (solar or fusion really)

[EnergyUnlimited]

Jokes apart, I think a very important issue is this OPEN QUESTION issue thing. You mention FBRs as open. I would say Thorium is an open issue as well, as it means breeding, and we have not been really successfull in breeding (except for breeding ourselves or cattle) for some time now. How many operating Thorium nuclear plants you know in the world?

There is distinct advantage with thorium breeding cycle.
Thorium can be converted into fissile U233 in certain type of conventional reactor subjected to only moderate modifications. This is NOT fast breeder process.
In fact fast neutrons are most unwanted in thorium breeding, as their presence leads to U232 byproduct, which is outright nuisance if present in nuclear fuel. Even if it does not quench fission process, it posess substantial radiological hazard in handling (exceeding plutonium 239 by orders of magnitude) and it is very unwelcomed by civilian engineers not even mentioning our poor weapon designers/manufacturing engineers, who are getting irradiated with high energy gamma radiation for free, if this isotope is present.
Fortunately it is easy to set thorium breeding in fashion preventing production of this nuisance impurity and some conventional reactor designs are well suited for this task.
Breeding factors can be marginally higfer than 1 in this process, which ensures ability of exhaustive thorium use.

Additional opportunity with thorium is particle accelelator assisted fission, which is of great safety advantage and has some perspective for the future (commercial plants applying it had not been built yet, but all necessary technology to do so is in place).

Because we still have plenty of uranium around, as well as nuclear engineers are "used to" it, there is currently not very much work on thorium breeding going on.
However few thorium rich but uranium poor countries (say India) are keenly pursuing this route.

Once uranium gets scarce or nationalised worldwide and not traded freely, than IMO thorium is bound to take over.

Nuclear opponents, however, use this argumentation: We do not produce electricity with FBRs nor we do it with Thorium. The only technologies which are used and are planned on are LWR+MOX+a little bit of CANDU. So lets only discuss LWRs.
This kind of argumentation is of course not very satisfactory, but in general, the absence of practically employed hi-tech solutions gives the opponents their argument.

I for myself, after analyzing data from the both sides came to the conclusion that we can mine ores with 20 ppm, but if we continue building LWRs, than it would be logistically too difficult to do. And we, which is pity of course, continue to build LWRs

If we stay with LWR + some MOX only, than within about sixty - hundred years we may switch off light and close the shop.
Low grade mineral uranium ores, even if of satisfactory EROEI - but I doubt it - are tedious to work with, and due to unsatisfactory production rates are likely to fail to provide sufficient supply to global nuclear sector.
Our only hope to keep LWR for long term future would be in successful large scale uranium recovery from sea water, but we do not have working technology yet, albeit there are some interesting initial results obtained.
It may be possible to convert some LWR into thorium breeders if need arise, but this is only my speculation (someone help here?).
I know no documented precedence of that.

[EnergyUnlimited]

I sort of think the best approach to dealing with waste is to stick it in dry storage casks until demand for spent fuel makes it economically viable to reprocess. Then crack it open and stick it in the reactors. Lots of nice fission platenoids that command high market value also.

I rather believe, that it is good idea to deal with waste as soon as it is reasonably possible.
It is not good idea to store more and more of it in stainless (but yet rusting casks) without clear idea, what to with it in the future.
You may also note, that after few thousands years of storage current "reactor grade" plutonium will transform itself into "weapon grade" without any external help due to half life differences of Pu238/239/240/241.
One could argue, that few thousands years is long enough not to bother about and some others would not see anything wrong with "selfenrichment". Neverthless it is good idea to remember about it.
And please note that plutonium "left alone" will be a perfect weapon material after few thousands years, but a reasonably good one only after few decades.

[EnergyUnlimited]

EnergyUnlimited,

I see your point. So you see, you fall between radical opponents and radical proponents:) Because radical proponents see FBRs as already built and tested at any scale, ready to run tomorrow morning, breeding at 10x, spewing pu239 like crazy and giving out millions of billions of TWh(e) per SECOND in the mean time Ok, that was a really radical one:):)

I had replied to your main question/enquiry in my previous post , as good as I can at the moment.
Now I reply to your joke part:
Yes, we already have devices capable to deliver TWhr per second (or even milisecond).
However those are not of use in electricity production.

[Tanada]

It may be possible to convert some LWR into thorium breeders if need arise, but this is only my speculation (someone help here?).
I know no documented precedence of that.

Look up the 'LWBR Shippingport' keywords on Google for confirmation that what I am telling you is true. In the mid 1975 the AEC (predecessor of the DOE) designed an experimental Light Water Breeder Reactor using the Shippingport facillity. The redesigned the core of the reactor so that in addition to regular shutdown negative controll rod (neutron absorbers) it also had positive controll rod (neutron emmiters). The bulk of the core was made up of 97% Thorium-232 with 3% HEU, the positive controll rods were made up of 94% Thorium and 6% HEU. With the positive controll rods and the negative controll rods all extracted from the reactor it would not run, the enrichment of the bulk of the fuel was designed to be too low for it to generate power in this condition. The positive controll rods were very slowly inserted until the reactor core acheived criticallity and began generating power in 1977. From then until 1982 with the expection of maintenance shutdowns the plant operated without refueling and without showing the gross signs of fuel depletion. After 5 years of operation they dissassembled and assayed the core at which time they determined that it had been breeding at a rate of 1.01. There was slightly more fissionable material in the core after the power run than before it.

Two things to keep in mind, the initial fissionable mass was HEU, 94% U-235. While U-235 is a good fission fuel it is not the best, for thermal neutrons U-233 is much better and for fast neutrons Pu-239 and Pu-241 are both superior. We use U-235 because we can get it from nature, which saves a lot of effort on our part, not because it is best. The LWBR breeds U-233 and as a result over time the U-233 came to dominate the fissionable fuel load in the reactor. When the reactor was started up it was probably breeding in the .92 range simply because it was fueled with U-235. The longer it ran the higher the ratio of U-233/U-235 became and the higher the breeding ratio as a result.

The other thing to keep in mind, though the reactor did not show any gross signs of fuel depletion even after 5 years, at some point the neutron absorbing effects of the fission fragments will become high enough to prevent breeding. After that threshold the reactor can still produce power for quite a while, probably another 5 years from that point. The Shippingport experiment was almost down to that point when the system was shut down for dissasembly and assay, it was estimated the plant could have run another 5 years, possibly longer, without refueling.

Using a Shippingport design LWBR with the same fuel design they used would allow you to operate a reactor for 10 or more years between refuelings. Current best use LWR are running on a 6 years cycle with refueling every 24 months. The economic difference between refuling every 120 months vs every 24 months should be obvious!

LWBR review

[sch_peakoiler]

EnergyUnlimited,

I see your point. So you see, you fall between radical opponents and radical proponents:) Because radical proponents see FBRs as already built and tested at any scale, ready to run tomorrow morning, breeding at 10x, spewing pu239 like crazy and giving out millions of billions of TWh(e) per SECOND in the mean time Ok, that was a really radical one:):)

I had replied to your main question/enquiry in my previous post , as good as I can at the moment.
Now I reply to your joke part:
Yes, we already have devices capable to deliver TWhr per second (or even milisecond).
However those are not of use in electricity production.

Cool!!! I give up! Your joke is truly superior to mine:) I would say more, those devices have a negative influence on all electricity production in approx. 100 miles around the place they are used

[J_S_Bokchoy]

Google search on "CANDU thorium" yielded a 2005 symposium stating that CANDU reactors, like the Bruce Power station providing most of Ontario's electricity, will run on thorium, virtually without modifications. Hard for me to understand what the disadvantages of deuterium moderated systems are compared to LWR's, when they eliminate the need for enrichment. d2o isn't cheap but the Girdler sulfide process sure looks a lot more like 1930s style low-tech than centrifuge systems, why aren't more orders for CANDU systems being placed? It's not for a lack of Canadians trying to export, they've been promoting this all along, and in fact the South Koreans use CANDU in tandem with LWR's to enable DUPIC recycling of spent fuel. There must be some strong political or technical objections for some reason or CANDU choice would seem a no-brainer. Oh well, guess the Canadians will just have to emerge as the world leaders in thorium usage.

[Dezakin]

Jokes apart, I think a very important issue is this OPEN QUESTION issue thing. You mention FBRs as open. I would say Thorium is an open issue as well, as it means breeding, and we have not been really successfull in breeding (except for breeding ourselves or cattle) for some time now. How many operating Thorium nuclear plants you know in the world?

There is distinct advantage with thorium breeding cycle.
Thorium can be converted into fissile U233 in certain type of conventional reactor subjected to only moderate modifications. This is NOT fast breeder process.
In fact fast neutrons are most unwanted in thorium breeding, as their presence leads to U232 byproduct, which is outright nuisance if present in nuclear fuel. Even if it does not quench fission process, it posess substantial radiological hazard in handling (exceeding plutonium 239 by orders of magnitude) and it is very unwelcomed by civilian engineers not even mentioning our poor weapon designers/manufacturing engineers, who are getting irradiated with high energy gamma radiation for free, if this isotope is present.

Actually U232 is highly desirable for thorium fuel cycles as a proliferation deterant.

Fortunately it is easy to set thorium breeding in fashion preventing production of this nuisance impurity and some conventional reactor designs are well suited for this task.
Breeding factors can be marginally higfer than 1 in this process, which ensures ability of exhaustive thorium use.

If you're breeding U233 free of U232, you have a fissile material that has most of the same nuclear weapons properties of plutonium minus the spontaneous fission, a highly desirable weapons material. Just use molten salt reactors or the once through fuel cycle. If you must breed U233 in LWRs or CANDU's, then make sure the process spikes it.

Additional opportunity with thorium is particle accelelator assisted fission, which is of great safety advantage and has some perspective for the future (commercial plants applying it had not been built yet, but all necessary technology to do so is in place).

I can say with total confidence that we will never have significant power supplemented with ADS. Its a cute design with massive costs, but ultimately a rube-goldberg machine. I have more confidence in fisson-fusion plants coming online before ADS gets any attention at all. Its a great political distraction that reduces energy efficiency by answering a question that can be better answered with safer critical reactors.

Because we still have plenty of uranium around, as well as nuclear engineers are "used to" it, there is currently not very much work on thorium breeding going on.
However few thorium rich but uranium poor countries (say India) are keenly pursuing this route.

Consider that U233 is good weapons material so long as its not spiked with U232, which probably has some impact on indias policy.

If we stay with LWR + some MOX only, than within about sixty - hundred years we may switch off light and close the shop.
Low grade mineral uranium ores, even if of satisfactory EROEI - but I doubt it - are tedious to work with, and due to unsatisfactory production rates are likely to fail to provide sufficient supply to global nuclear sector.

Say what? On what do you base that?

I like the thorium breeder concept as much as anyone, but this is being willfully ignorant of the production capacity of medium grade ores.