YELLOWCAKE: There should be enough uranium to fuel the world's current fleet for more than 200 years.
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Supplemental Material
How long will global uranium deposits fuel the world's nuclear reactors at present consumption rates?
Steve Fetter, dean of the University of Maryland's School of Public Policy, supplies an answer:
If the Nuclear Energy Agency (NEA) has accurately estimated the planet's economically accessible uranium resources, reactors could run more than 200 years at current rates of consumption.
Most of the 2.8 trillion kilowatt-hours of electricity generated worldwide from nuclear power every year is produced in light-water reactors (LWRs) using low-enriched uranium (LEU) fuel. About 10 metric tons of natural uranium go into producing a metric ton of LEU, which can then be used to generate about 400 million kilowatt-hours of electricity, so present-day reactors require about 70,000 metric tons of natural uranium a year.
According to the NEA, identified uranium resources total 5.5 million metric tons, and an additional 10.5 million metric tons remain undiscovered—a roughly 230-year supply at today's consumption rate in total. Further exploration and improvements in extraction technology are likely to at least double this estimate over time.
Using more enrichment work could reduce the uranium needs of LWRs by as much as 30 percent per metric ton of LEU. And separating plutonium and uranium from spent LEU and using them to make fresh fuel could reduce requirements by another 30 percent. Taking both steps would cut the uranium requirements of an LWR in half.
Two technologies could greatly extend the uranium supply itself. Neither is economical now, but both could be in the future if the price of uranium increases substantially. First, the extraction of uranium from seawater would make available 4.5 billion metric tons of uranium—a 60,000-year supply at present rates. Second, fuel-recycling fast-breeder reactors, which generate more fuel than they consume, would use less than 1 percent of the uranium needed for current LWRs. Breeder reactors could match today's nuclear output for 30,000 years using only the NEA-estimated supplies.
Editor's Note: This question was submitted by G. Peck of Seward, Alaska and will be printed in the March 2009 issue of Scientific American.
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28 Comments
Add CommentThis article is woefully inadequate as a response to the question. For starters, it doesn't address proposed increases in nuclear power; "at current rates of consumption" is a meaningless phrase that is often bandied about to give a false impression of resource longevity. The response also doesn't address production rates. We all know that resources tend to be mined from the most abundant and easiest to reach reserves first. Later production is inevitably more difficult and likely to peak at some stage. It's important to have an understanding of when resource extraction will peak and it's likely decline curve. Attempts to extract rate of water processing that would be required to extract enough uranium to power the world's nuclear plants in the future.
Reply | Report Abuse | Link to thisPlease provide thoughtful, practical, answers in future. This one falls far short of that.
Apologies for the odd last sentence of the first paragraph; I'm not sure what happened there. I was attempting to talk about the very high rate of water processing that would be needed to extract uranium from sea water, enough to power even present day needs. The article says that there is enough uranium in seawater to last 60,000 years at current consumption rates but can uranium be produced from seawater at current consumption rates (practically, not theoretically), never mind future anticipated rates?
Reply | Report Abuse | Link to thisAuthor, please expand on the claim that fuel-recycling fast-breeder reactors "generate more fuel than they consume". If this is true, then surely we have an infinite source of nuclear energy!
Reply | Report Abuse | Link to thisFor a more detailed take on uranium fuel supplies see this article: http://www.sciam.com/article.cfm?id=finding-fissile-fuel
Reply | Report Abuse | Link to thisA key point the author failed to mention: uranium is NOT the only fuel available for nuclear plants. Thorium can also be used in existing reactors with little or no modifications, and thorium is three times more abundant than uranium in the earth's crust. Also, while only 0.7% of uranium is fissile, fully 100% of thorium may be "burned" in a reactor. The abundance and availability of thorium increases the available fuel supply to well beyond 1000 years. By then I think we'll have another energy solution!
Reply | Report Abuse | Link to thisJohn Wheeler This Week in Nuclear Podcast
I keep hearing this thing about thorium and yet it just isn't being used. Why not?
Reply | Report Abuse | Link to thisI believe uranium supplies are more than adequate because the current fuel costs are a very small cost of the overall cost for current reactors. Fuels costs could double or triple & not have much impact on the overall cost of producing electricty.
Reply | Report Abuse | Link to thisAt $200 per lb, a lot more sites become economical to mine
Then you add increasing efficiencies through various technologies
Even just the replacement of old reactors with current reactors
There is 50 years supply without trying & in 50 years technology will have moved so far if the uranium starts to get scarce there will be that many alternatives it won't matter. I think for the moment we should make the most of nuclear as one of the solutions to climate change & energy security - Look at Kazazstan it come from nowhere in the last few years and will overtake Canada as the world's biggest producer.
Mines are coming online in Africa, Cigar Lake will get going with its huge reserves BHP has massive reserves at Olympic Dam - and if supply gets a little tight an increase in price will fix things
I believe uranium supplies are more than adequate because the current fuel costs are a very small cost of the overall cost for current reactors. Fuels costs could double or triple & not have much impact on the overall cost of producing electricty.
Reply | Report Abuse | Link to thisAt $200 per lb, a lot more sites become economical to mine
Then you add increasing efficiencies through various technologies
Even just the replacement of old reactors with current reactors
There is 50 years supply without trying & in 50 years technology will have moved so far if the uranium starts to get scarce there will be that many alternatives it won't matter. I think for the moment we should make the most of nuclear as one of the solutions to climate change & energy security - Look at Kazazstan it come from nowhere in the last few years and will overtake Canada as the world's biggest producer.
Mines are coming online in Africa, Cigar Lake will get going with its huge reserves BHP has massive reserves at Olympic Dam - and if supply gets a little tight an increase in price will fix things
Thorium is not used as commonly as Uranium/Plutonium as a nuclear fuel because it was not as satisfactory for the combined needs of weapons and power generation when the USA and other major nuclear countries chose in the 1950s to standardized on one fuel cycle and infrastructure. Thorium is in many respects better suited to fill the role of power generation but is difficult (but surely possible) to use to make a weapon. Thorium has a clear advantage over Uranium fuel cycle in terms of producing a much reduced amounts of high level nuclear waste. Thorium fuel when "burned" through fission produce a significantly smaller amount (about 1 part in 100) of minor Actinide wastes which typically have to be stored in Yucca Mountain, Nevada for ~25,000 years. Thorium reactors produce a much higher proportion of fission products as their wastes that are easier to manage requiring less than 400 years to fully decay to benign levels. 83% of the fission products produced by Thorium reactors decay to the level of the radioactive background within 10 years. The remaining 17% of the fission products decay to benign levels in less than 400 years.
Reply | Report Abuse | Link to thisNRC regulations would need to be upgraded to allow modern Thorium reactors and there has not as yet been funding to permit this.
Thorium is three times as abundant as natural Uranium and 550 times as abundant as U-235 which in the principal Uranium isotope actually burned in current Light Water Reactors. Thorium is a nuclear fuel of the future that will someday take over from Uranium fuel cycle technology as it becomes more widely realized how much better technology it is from the standpoint of high level waste generation. Every year we delay switching our nuclear fuel over to Thorium adds another 2000 metric tons of Spent Nuclear Fuel waste to Yucca Mountain to remain a long term worry for our Children's Children. Thorium Molten Salt Reactors are one of the nicest implementations of Thorium Fuel Cycle technology and have some of the best intrinsic safety features and the best economics.
Positive Change should include Changing America's Nuclear Fuel Cycle to Thorium.
I agree that present consumption rate can be misleading, particularly if consumption rates have been increasing or decreasing. But the question was framed in terms of present consumption rates: "How long will global uranium deposits fuel the world's nuclear reactors at present consumption rates?" In addition, the production of nuclear electricity (and therefore the consumption of uranium for fuel) has increased slowly over time.
Reply | Report Abuse | Link to thisAny discussion of future changes in the rate of consumption inevitably introduces additional assumptions, many of which are debatable. Some knowledgeable analysts believe nuclear electricity will increase substantially; others that it will increase modestly; others that it will decrease.
Bear in mind that I was asked to provide a 200-word answer. It would have been impossible to address the many possible scenarios for future consumption in this limited space.
Japanese researchers have demonstrated the extraction of uranium from seawater using various adsorbents on floating platforms. The uranium can be recovered and the adsorbent recycled. Natural ocean currents are used to transport seawater; no pumping is required.
Reply | Report Abuse | Link to thisThe word limit forced me to use this often-used short-hand to explain the concept of breeding. Here is a more detailed explanation:
Reply | Report Abuse | Link to thisUranium contains two main isotopes: U-235 and U-238. The rare isotope, U-235, can be far more easily fissioned than the more common isotope, U-238. U-235 is said to be "fissile," because it can be fissioned by neutrons of any energy. U-238, by contrast, can be fissioned only by fast neutrons. When slow neutrons are absorbed by U-238, they are absorbed to produce U-239; after two radioactive decays, an isotope of plutonium--Pu-239--results. Pu-239, like U-235, is fissile.
Virtually all of the fissions that occur in a light-water reactor are the result of slow neutrons--either U-235 or Pu-239. The Pu-239 is said to have been was "bred" from U-238. The number of new fissile atoms produced per fissile atom consumed is the "breeding ratio" or "conversion ratio". In a light-water reactor, the conversion ratio is about 0.6. But in a breeder reactor, the conversion ratio is greater than 1: more plutonium is produced (from neutron absorption by U-238) than is consumed through fission. In theory, all of the U-238 can be consumed by a breeder reactor--either directly through fission, or indirectly through conversion to plutonium.
The question concerned the availability of uranium, which was difficult enough to answer in 200 words. Although only 0.7% of uranium is the fissile isotope U-235, this is sufficient to sustain a chain reaction in a graphite or heavy-water-moderated reactor. Enrichment can be used to increase the concentration of U-235 to 3-5% for use in a light-water-moderated reactor. In all of these cases, some of the neutrons resulting from the U-235 fissions will be absorbed by the non-fissile isotope U-238, producing Pu-239, which is fissile. In these reactors, a significant fraction of the fissions are from plutonium isotopes.
Reply | Report Abuse | Link to thisWorld thorium resources are several times larger than world uranium resources, but the only thorium isotope that exists in nature is Th-232, which is not fissile and cannot sustain a chain reaction. Thorium, unlike uranium, cannot be used directly as nuclear fuel. But Th-232 can absorb a neutron and decay to U-233, which is fissile. Thus, Th-232 can play the role of U-238 in current reactors: a fertile material that is used to produce additional fissile material. But you still have to have to create a chain reaction as a source of neutrons to convert Th-232 to U-233. This could be done initially with fuels that contain U-235 (or Pu-239 bred from U-238). The use of thorium can greatly decrease the use of uranium, but cannot eliminate it entirely.
I addressed the same subject a few months ago (Fueling our Nuclear Future at: http://newpapyrusmagazine.blogspot.com/2008/10/fueling-our-nuclear-future.html).
Reply | Report Abuse | Link to thisCANDU heavy water reactors could stretch current terrestrial uranium supplies at least 5 times if fertile thorium 232 were used with fissile nuclear material.
Marcel F. Williams
http://newpapyrusmagazine.blogspot.com/
I addressed the same subject a few months ago (Fueling our Nuclear Future at: http://newpapyrusmagazine.blogspot.com/2008/10/fueling-our-nuclear-future.html).
Reply | Report Abuse | Link to thisCANDU heavy water reactors could stretch current terrestrial uranium supplies at least 5 times if fertile thorium 232 were used with fissile nuclear material.
Marcel F. Williams
http://newpapyrusmagazine.blogspot.com/
Like most commodities there can be local shortages like India has not yet got out of and reactors being short of fuel. The solution also is there-fast reactors. No attempt must be made to hinder the program of those who dare to attempt it (In spite of risky sodium fuel) under Fissile material considerations or by misplaced interpretation of NPT.
Reply | Report Abuse | Link to thisAs someone has pointed out the modern nuclear industry is wedded to the weapons making use of U235. It's time to destroy that link and start developing natural uranium and thorium using fuel-cycles - make enrichment illegal everywhere (after a change over to better fuel cycles) not just in countries we don't trust with bombs (like N.Korea and Iran.) That's my idealism speaking, but a bit of governmental will would be nice to see.
Reply | Report Abuse | Link to thisAccording to the International Atomic Energy Agency, there is only enough uranium at current rates of consumption to last 30 years, or 70 years if we consider probable ore deposits yet to be prospected. Who is right?
Reply | Report Abuse | Link to thiseco-steve: I would take the numbers in this article over the IAEA numbers. They are making very conservative/pessimistic predictions.
Reply | Report Abuse | Link to thisThere are some good comments here, from some people who have clearly done some study on the topic. I think all would agree that with a little creativity in new reactor designs, making decissions on issues like extraction and reprocessing on technical rather than political merit, and the advances that will almost certainly occur, fuel is not going to be the limiting factor.
Mike B I have done quite a bit of checking of largely differing sources, and there is general agreement that 70 years is an accurate estimate taking into consideration the current state of technology. As for other possible technological progress, there is no concensus that such techniques are as yet viable. If Nuclear technology was applied worldwide, greenhouse gases would only be reduced by 7%, and ores would last but a few years!
Reply | Report Abuse | Link to thiseco-steve;
Reply | Report Abuse | Link to thisI assume that if you believe that 70 years is not enough for something to last, you aren't intending to have any children. After all, they probably won't average lasting 70, and there's no consensus that they would be able to replace themselves, so what's the point?
If you want to do some checking, take a look at how long the known sources of the rare-earth metals needed for the super strong magnets that make wind turbines viable will last at the current and/or projected usage rates.
I assume that you support the use of used fryer oil to power some biodiesel vehicles, even though it is obvious that there will never be enough used oil to make a noticeable decrease in the production of greenhouse gasses.
The we shouldnt build new reactors because the uranium will run out argument is the latest red herring by the anti-nuke club, and it is no more evidence based than there is no way to deal with radioactive waste ploy.
There are vast quantities of uranium that is obtainable with the technologies we already have. Some are more expensive than others to obtain. Kind of like the materials to build wind systems, or solar power systems, or tidal power systems, or, well, everything. But if the price of the alternatives goes up high enough, or new technology drives extraction costs low enough, the uranium is there to be had.
Hi! Mike B : No, I am an advocate of biochar technology. The future will be hydrogen-based energy instead of carbon-based. The hydrogen comes from pyrolysing biomass, the residue being charcoal, which can be added to soil as an enhancer. The biomass captures atmospheric CO2 which is therefore no longer a GHG pollutant. I have grandchildren and I do everything I can to help the environment. I am quite optimistic. See www. eprida.com
Reply | Report Abuse | Link to thiswith all the data in, the future is still "debatable".
Reply | Report Abuse | Link to thisI don't know whether to scream or yawn.
Anyway, isn't this our vacation?
I'm a great fan of Sciam and am usually content with the content.
Reply | Report Abuse | Link to thisHowever, having done a bit of research on nuclear power myself, I
found this months Ask the Experts article on global uranium deposits
anything but expert. This answer lacks integrity at best and is
otherwise simply misleading. First of all an expert would have pointed
out that consumption of uranium deposits is rising, so while valid as
an exercise, calculating future reserves at current consumption will
overestimate reserves.
From: http://www.rcresearch.com.au/documents/uranium/reports/0/australia/
"There are 376 new nuclear reactors planned or proposed globally as of
Dec 08, up from 318 Aug 08 (+58 units, +18%). The main increases are
UAE (11), Italy (10), UK (6), Vietnam (6), and Poland (5). ...
Currently there are 439 nuclear power reactors in operation and 39
under construction. A total of 61 new reactors are expected to be
commissioned by 2014."
Secondly Steve Fetter uses the NEA as his single source of
information. This would be fine if the source were an independent
organisation with balanced information. However, the NEA is an
organisation which is focused on the expansion of nuclear power as an
energy source. Deposits as reported by the NEA are presumed to be of
equal quality, however the quality of deposits are known to vary and
the highest quality deposits are consumed first and will finish in
decades. This means counting tonnes of uranium left is not to count
energy equivalent tonnes of uranium. The last paragraph of the article
is simply unworthy of Sciam. Price is far from the only problem with
these technologies. Fastbreeders are not technologically feasible now
and safety concerns mean they might never become feasible. As for
extracting uranium from sea water, this is a fallacy. The energy
required is simply more than will be produced from the collected
uranium.
See the following for an example of a more complete analysis of
uranium deposits:
http://www.stormsmith.nl/publications/Energy%20from%20Uranium%20-%20July%202006.pdf
For the love of Sciam, please make sure your experts have spent more than 15 minutes researching their topic of expertise next time.
Reply | Report Abuse | Link to thisThis is a comment on the answer to the question "How long will the world's uranium supplies last?
It's interesting that you didn't try to combine the two technologies that are briefly described near the end of the response. I haven't tried to work out the math, but it would seem the two technologies, used together, could extend supplies out to the range of millions of years.
On some time scale, the uranium in seawater is, in effect, a renewable resource. This is because the source of that uranium is material eroded from the land and transported to the ocean. I seem to recall reading an article many years ago by Bernard L. Cohen that addressed this topic. I couldn't find the article in my personal library, but (based on reviewing a list of titles on his web site) it MIGHT have been: "Breeder Reactors - A Renewable Energy Source," Am. Jour. Phys, 51, 75 (1983).
Really, you thought they would have learned a lesson with oil to be more informed and hopefully have bit more foresight.
Reply | Report Abuse | Link to thisProf. Hans Peter Duerr, Director Emeritus Max Planck Institute for Physics, Munich, Germany said, when agitations against the Plant in Tirunelveli was brought out to his notice :Duerr observed that the one way of disposing the waste from nuclear energy is blowing off bombs. So many countries, which have reactors, dont know where to put it, he added. However, he claimed that he had invented a technology that could be the solution for sustainable energy needs and an alternate for the nuclear energy.He also has an opinion the uranium reserves in the world will only last for 100 years.who is telling the truth?
Reply | Report Abuse | Link to thisI'm not sure what is meant by "sustainable energy needs". There are "energy needs" and there are sustainable ways of producing energy. The former may not be satisfied by the latter. Ultimately, the only sustainable (in terms of the habitable lifetime of the planet) energy source is the sun (primarily) but the sustainable rate of harvest isn't necessarily more than a tiny fraction of solar irradiation - that science has yet to be done.
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