Why bury nuclear waste, when it could meet the world’s energy needs?

By George Monbiot. Published in the Guardian 6th December 2011

 “These decisions are the result of an almost mediaevel misrepresentation of science and technology. For while the greens are right about most things, our views on nuclear power have been shaped by weapons-grade woo.”

It’s a devastating admission to have to make, especially during the climate talks in Durban. But there would be no point in writing this column if I were not prepared to confront harsh truths. This year the environmental movement to which I belong has done more harm to the planet’s living systems than climate change deniers have ever achieved.

As a result of shutting down its nuclear programme in response to green demands, Germany will produce an extra 300 million tonnes of carbon dioxide between now and 2020(1). That’s almost as much as all the European savings resulting from the energy efficiency directive(2). Other countries are now heading the same way. These decisions are the result of an almost mediaevel misrepresentation of science and technology. For while the greens are right about most things, our views on nuclear power have been shaped by weapons-grade woo.

A fortnight ago, the Guardian examined the work of a Dr Chris Busby(3,4). We found that he has been promoting anti-radiation pills and tests to the people of Japan, which scientists have described as useless and baseless. We also revealed that people were being asked to send donations, ostensibly to help the children of Fukushima, to Busby’s business account in Aberystwyth. We found that scientists at the NHS had examined his claims to have detected a leukaemia cluster in north Wales and discovered that they arose from a series of shocking statistical mistakes. Worse still, the scientists say, “the dataset has been systematically trawled”: they’re accusing him of picking the data that suits his case(5). Yet Busby, until our report was published, advised the Green party on radiation. His “findings” are widely used by anti-nuclear activists.

Last week in the New York Times, the anti-nuclear campaigner Helen Caldicott repeated a claim which has already been comprehensively discredited: that “close to 1 million people have died of causes linked to the Chernobyl disaster”(6). The “study” on which it is based added up the excess deaths from a vast range of conditions, many of which have no known connection to radiation, in the countries affected by Chernobyl – and attributed them to the accident(7,8,8a). Among these conditions was cirrhosis of the liver. Could it have any other possible cause in eastern Europe? Earlier this year, when I asked Caldicott to provide scientific sources for the main claims she was making, she was unable to do so(9,10). None of this has stopped her from repeating them, or has prevented greens from spreading them.

Anti-nuclear campaigners have generated as much mumbo-jumbo as creationists, anti-vaccine scaremongers, homeopaths and climate change deniers. In all cases, the scientific process has been thrown into reverse: people have begun with their conclusions, then frantically sought evidence to support them.

The temptation, when a great mistake has been made, is to seek ever more desperate excuses to sustain the mistake, rather than admit the terrible consequences of what you have done. But now, in the UK at least, we have an opportunity to make amends. Our movement can abandon this drivel with a clear conscience, for the technology I am about to describe ticks all the green boxes: reduce, reuse, recycle.

Let me begin with the context. Like other countries suffering from the idiotic short-termism of the early nuclear power industry, the UK faces a massive bill for the storage and disposal of radioactive waste. The same goes for the waste produced by nuclear weapons manufacturing. But is this really waste, or could we see it another way?

In his book Prescription for the Planet, the environmentalist Tom Blees explains the remarkable potential of integral fast reactors (IFRs)(11). These are nuclear power stations which can run on what old nuclear plants have left behind. Conventional nuclear power uses just 0.6% of the energy contained in the uranium that fuels it. Integral fast reactors can use almost all the rest. There is already enough nuclear waste on earth to meet the world’s energy needs for several hundred years, with scarcely any carbon emissions. IFRs need be loaded with fissile material just once. From then on they can keep recycling it, extracting ever more of its energy, until a small fraction of the waste remains. Its components have half-lives of tens rather than millions of years. This makes them more dangerous, but much easier to manage in the long term. When the hot waste has been used up, the IFRs can be loaded with depleted uranium (U-238), of which the world has a massive stockpile(12).

The material being reprocessed never leaves the site: it remains within a sealed and remotely-operated recycling plant. Anyone trying to remove it would quickly die. By ensuring the fissile products are unusable, the IFR process reduces the risk of weapons proliferation. The plant operates at scarcely more than atmospheric pressure, so it can’t blow its top. Better still, it could melt down only by breaking the laws of physics. If the fuel pins begin to overheat, their expansion stops the fission reaction. If, like the Fukushima plant, an IFR loses its power supply, it simply shuts down, without human agency. Running on waste, with fewer pumps and valves than conventional plants, they are also likely to be a good deal cheaper(13).

So there’s just one remaining question: where are they? In 1994 the Democrats in the US Congress, led by John Kerry, making assertions as misleading as the Swift Boat campaign that was later deployed against him(14), shut down the research programme at Argonne National Laboratories that had been running successfully for 30 years. Even Hazel O’Leary, the former fossil fuel lobbyist charged by the Clinton administration with killing it, admitted that admitted that “no further testing” is required to prove its feasibility(15).

But there’s a better demonstration that it’s good to go: last week GE Hitachi (GEH) told the British government that it could build a fast reactor within five years to use up the waste plutonium at Sellafield, and if it doesn’t work, the UK won’t have to pay(16). A fast reactor has been running in Russia for 30 years(17) and similar plants are now being built in China and India(18,19). GEH’s proposed PRISM reactor uses the same generating technology as the IFR, though the current proposal doesn’t include the full reprocessing plant. It should.

If the government does not accept GEH’s offer, it will, as the energy department revealed on Thursday, handle the waste through mixed oxide processing (mox) instead(20). This will produce a fuel hardly anyone wants, while generating more waste plutonium than we possess already. It will raise the total energy the industry harvests from 0.6% to 0.8%(21).

So we environmentalists have a choice. We can’t wish the waste away. Either it is stored and then buried. Or it is turned into mox fuels. Or it is used to power IFRs. The decision is being made at the moment, and we should determine where we stand. I suggest we take the radical step of using science, not superstition, as our guide.

http://www.monbiot.com

References:

1. http://www.newscientist.com/article/mg21128236.300-the-carbon-cost-of-germanys-nuclear-nein-danke.html

2. 335mt.

3. http://www.guardian.co.uk/environment/2011/nov/21/christopher-busby-radiation-pills-fukushima

4. http://www.monbiot.com/2011/11/22/how-the-greens-were-misled/

5. John A Steward, Ceri White and Shelagh Reynolds, 2008. Leukaemia incidence in Welsh children linked with low level radiation—making sense of some erroneous results published in the media. Journal of Radiological Protection 28, 33–43. doi:10.1088/0952-4746/28/1/001

http://iopscience.iop.org/0952-4746/28/1/001/pdf/0952-4746_28_1_001.pdf

6. http://www.nytimes.com/2011/12/02/opinion/magazine-global-agenda-enough-is-enough.html

7. Alexey V. Yablokov, Vassily B. Nesterenko and Alexey V. Nesterenko, 2010. Chernobyl: Consequences of the Catastrophe for People and the Environment. Annals of the New York Academy of Sciences. I have this in pdf form, sent to me by the NYAS.

8. The “study” was published by the New York Academy of Sciences, which has now disowned it. Here’s what it says: “In no sense did Annals of the New York Academy of Sciences or the New York Academy of Sciences commission this work; nor by its publication do we intend to independently validate the claims made in the translation or in the original publications cited in the work. The translated volume has not been peer-reviewed by the New York Academy of Sciences, or by anyone else.” Sent to me by Douglas Braaten, Director and Executive Editor, Annals of the New York Academy of Sciences, 2nd April 2011.

8a. Here’s a devastating review of the “study”: MW Charles, 2010. Review of Chernobyl: consequences of the catastrophe for people and the environment. Radiation Protection Dosimetry (2010) 141(1): 101-104. doi: 10.1093/rpd/ncq185. http://rpd.oxfordjournals.org/content/141/1/101.full

9. http://www.monbiot.com/2011/04/04/evidence-meltdown/

10. http://www.monbiot.com/2011/04/13/why-this-matters/

11. Tom Blees, 2008. Prescription for the Planet: the painless remedy for our energy and environmental crises. ISBN 1-4196-5582-5

12. As above.

13. As above.

14. http://www.gpo.gov/fdsys/pkg/CREC-1994-06-30/html/CREC-1994-06-30-pt1-PgS7.htm

15. Amazingly, Kerry himself quotes this with no sense of the way in which it flatly contradicts everything else he’s been saying: “I quote from her letter of June 27: ‘No further testing of the Integral Fast Reactor concept is required to prove the technical feasibility of actinide recycle and burning in a fast spectrum reactor, such as the Experimental Breeder Reactor in Idaho. The basic physics and chemistry of this technology are established.’”

16. This pledge was made during a meeting between GEH and UK government officials and advisers on 30th November 2011.

17. http://en.wikipedia.org/wiki/BN-600_reactor

18. http://www.world-nuclear.org/info/inf53.html

19. http://bravenewclimate.com/2011/11/27/china-fr-summary/

20. http://www.decc.gov.uk/en/content/cms/consultations/plutonium/plutonium.aspx

21. http://bravenewclimate.com/2011/06/04/uk-pu-cc

28 comments

  1. Apparently Steven Conroy’s uncles work at Sellafield as we heard in his impassioned antinuclear speech. Yet SC can find $36 bn for broadband for yokels (like myself) who have been grateful just for dialup internet. That money would buy at least a couple of AP 1000s and a PRISM to eat the leftovers.

  2. A powerful article. I like it – and I agree Germany has made a BIG mistake. I agree too about the terrible anti-science denialism practiced by the greens that are a barrier to real solutions

    But then like all such claims I read of a possible wonderful nuclear solution I am skeptical. Open minded, but skeptical. Most of the references are to newspapers and blogs. I don’t doubt the reporting of the politics – but what I would like to see is a lot more solid technical analysis of the feasibility of the proposed solution from well credentialed people that is also open to and subject to critical review (not uninfomred attack by ideologues – genuine scientific and technical critical review)

    But perhaps the GEH offer is an interesting one? It is certainly putting their money where their mouth is. Nuclear (perhaps for all the wrong reasons) is political poison in the west at the moment. If the UK goveernment rejects the offer I wonder if it will be made elsewhere?

    1. Great Britain has a major problem.with a large.plutonium stockpile they don’t want. Actual poison may trump political poison, and nuclear does not seem to have been marginalized in the UK as much.as elsewhere.

      It is necessary to get the more technical references out there. Suggest you speed some time at Brave New Climate where a whole page is devoted to IFR articles.and discussion.

      1. Thanks Ben, I did a while ago (where I studied critiques of BZE and Jacobson & Delucchi whilst reading same) and am doing so again.

        Blog sites are great, and as much as I respect the scientific expertise there I do prefer peer reviewed literature. Still have an open mind though and it’s interesting to see which way the developing world (India and China) is going

        http://www.smartplanet.com/blog/intelligent-energy/meet-the-future-of-nuclear-power-8-guys-in-china/11120

        https://theconversation.edu.au/how-do-you-power-a-billion-lives-4596

        Indicating India and China (more than 1/3 of the world’s population) are moving ahead on nuclear.

        http://www.bloomberg.com/news/2011-12-07/buffett-gets-u-s-incentive-high-power-rates-in-2-billion-solar-farm-bet.html
        http://www.bloomberg.com/news/2011-12-02/india-s-solar-power-bid-prices-sink-to-record-consultant-says.html
        http://iopscience.iop.org/1748-9326/6/4/045102
        But there’s a fair bit of movement on Solar and Wind too.
        Will be interesting to see what the future holds – but It’s pretty clear to me that both nuclear and solar/wind are going to have important roles to play. As to which does more? Hard to say – and I really don’t care – as long as we continue to replace fossil fuel based generation it’s a step forward.

        1. Sorry that took a while to approve. Limit on links.

          More and more, it sounds like our positions converge… how dull. You will read on my “Welcome to Decarbonise SA” page that I too am basically happy to see anything do the job, but see nuclear as the missing component of an effective overall strategy.

          Perhaps the outstanding issue is whether Australia is the “special case” that does not need to pursue nuclear with vigour. I say certainly it is not.

  3. > In his book Prescription for the Planet, the environmentalist Tom Blees explains the remarkable potential of integral fast reactors (IFRs). These are nuclear power stations which can run on what old nuclear plants have left behind.

    Not really. Making IFR run on spent fuel is perhaps possible, but most likely uneconomic: the problems and corresponding costs of loading HIGHLY radioactive fuel into reactor will be large. Also, spent fuel is not uniform in its composition (more problems with making IFR run stably). IFR will most likely be fueled with ordinary (fresh, non-spent) nuclear fuel.

    > Conventional nuclear power uses just 0.6% of the energy contained in the uranium that fuels it.

    Not really, currently almost additional 1% is produced from Pu which is bred in-situ from U-238. But it’s a minor detail

    > IFRs need be loaded with fissile material just once. From then on they can keep recycling it, extracting ever more of its energy, until a small fraction of the waste remains.

    Not really. IFRs can run for about ~30 years between refueling, yes, but resulting waste is ANYTHING but “small fraction”. In fact, by necessity it has much higher fraction of fission products, with more varied composition. And it still would contain a lot of transuranics. It will still need to be cooled and reprocessed, just as light water reactor’s waste. But because of 30 year refueling cycle, there will be less waste, yes.

    > Its components have half-lives of tens rather than millions of years.

    No. There still _will be_ transuranics in the waste.

    > If the fuel pins begin to overheat, their expansion stops the fission reaction. If, like the Fukushima plant, an IFR loses its power supply, it simply shuts down, without human agency.

    Wrong. Yes, fission will stop. But Fuku’s problem wasn’t fission either, it was decay heat. IFR also generates decay heat (in fact, somewhat more of it than light water reactors). If you don’t cool IFR after shutdown, you can end up with meltdown too. No difference here.

    I agree on the point that burying nuclear waste without reprocessing is STUPID. The best thing to do is to store it in dry casks for 30-100 years (long cool-down period dramatically reduces radioactive releases during reprocessing – think about where Kr-85 (half-life: 10 years) goes today during reprocessing), then reprocess, then bury fission products, and recycle uranium and transuranics.

    1. “Not really. Making IFR run on spent fuel is perhaps possible, but most likely uneconomic”: I would require reasons beyond your generalised experience and knowledge to think you know better than Blees on the economics of IFR, who has worked, and continues to work, very closely with those who devised the system. Feel free to fill me in.

      “the problems and corresponding costs of loading HIGHLY radioactive fuel into reactor will be large.” That is not going to be news to Blees or those who designed the system. Indeed, part of the point of IFR is the I standing for integral, whereby the on site pyroprocessing for fuel recycling is indeed conducted in a highly radioactive environment from which nothing can be easily removed. To quote “One of the great benefits of the IFR over thermal reactors is that the reprocessing facility is located in the same complex as the reactor itself—hence the “Integral” in “Integral Fast Reactor” (IFR). In an IFR plant, all actinides—including plutonium—are kept sequestered in an extremely radioactive environment while they are repeatedly sent through the fast reactor until they are transformed into energy.” (Prescription for the Planet pg 137)

      “Also, spent fuel is not uniform in its composition (more problems with making IFR run stably).” Again, I would need a good reason to believe you are thinking of something they have not

      “IFR will most likely be fueled with ordinary (fresh, non-spent) nuclear fuel.” Well, I think it will most likely be started with ordinary nuclear fuel and then “the new actinides used to augment the
      spent IFR fuel during its reprocessing can come from the nuclear “waste” from thermal reactors, which we are all so concerned about. Plutonium and uranium from decommissioned nuclear weapons can also be incorporated into fast-reactor fuel.” (Prescription for the Planet pg 134)

      “But resulting waste is ANYTHING but “small fraction”.” I understand it to be about 1% by volume of that from a current LWR. Is that your understanding?

      “In fact, by necessity it has much higher fraction of fission products, with more varied composition.” My understanding is that it basically IS fission products. Highly radioactive, very small in volume.

      “And it still would contain a lot of transuranics…There still _will be_ transuranics in the waste.” That is not my understanding. “…the fuel can then be recycled on-site in a process that removes the fission byproducts and incorporates the actinides from the used fuel into new fuel rods, which are then reloaded into the reactor.” (P4TP pg 133). If there are transuranics remaining, can you define “a lot”? Is it significant?

      “It will still need to be cooled and reprocessed, just as light water reactor’s waste. But because of 30 year refueling cycle, there will be less waste, yes”. Less waste, yes. The reprocessing is the I part of IFR discussed above. The true waste, being the fission products, would need to be vitrified and safely stored (or confidently disposed of) for the few hundred years required to return to safe levels.

      “Yes, fission will stop. But Fuku’s problem wasn’t fission either, it was decay heat. IFR also generates decay heat (in fact, somewhat more of it than light water reactors). If you don’t cool IFR after shutdown, you can end up with meltdown too. No difference here.” Of course you need to cool it, but actually, big difference here. Firstly the shut down is passive as you acknowledge. Secondly, so is the cooling because the coolant is liquid sodium at near-atmospheric pressure. It requires no power to remove the heat, unlike the water coolant of Fukushima and other LWRs of similar vintage. Granted, Monbiot did not cover that feature. I did over here http://theconversation.edu.au/safe-zero-carbon-and-proven-is-fourth-generation-nuclear-the-energy-solution-4204 . In 1986 at Argonne, they ran both Loss of Flow Test and Loss of Heat Sink Test. The reactor stabilised itself with no intervention, including control of decay heat (P4TP pg 142)

      1. Ah, so they plan to have a reprocessing plant incorporated into every reactor unit? This indeed changes the picture – it allows to eventually burn all uranium and transuranics to fission products.

        But having a reprocessing plant and fuel fabrication facility incorporated into every unit is going to be costly, and increase possibilities for radioactive releases – as compared to having one centralized plant, like French are doing it now.

        > > Yes, fission will stop. But Fuku’s problem wasn’t fission either, it was decay heat. IFR also generates decay heat (in fact, somewhat more of it than light water reactors). If you don’t cool IFR after shutdown, you can end up with meltdown too. No difference here.
        > Of course you need to cool it, but actually, big difference here. Firstly the shut down is passive as you acknowledge.

        Sorry, but you fell prey for market speak. ALL sane reactor designs have negative thermal coefficient, so when stopped, they heat up, reactivity decreases, and power stabilizes. Which can be sold as “it stops automatically” – glossing over the fact that it’s not enough to stop the fission, we need to remove constantly generated decay heat.

        > Secondly, so is the cooling because the coolant is liquid sodium at near-atmospheric pressure. It requires no power to remove the heat, unlike the water coolant of Fukushima and other LWRs of similar vintage.

        Again, water or sodium makes no big difference to the “passiveness” of heat removeal. Isolation Condensers on Fukushima Unit 1 are passive systems. As you see, this did not help – personnel need to also know how to activate them, which it did not know (wasn’t trained to do).

        Basically, reactors with almost any coolant can be designed to be passively cooled after shutdown, it’s not a feature which is unique to IFR. Why many existing reactors weren’t designed that way is a different question.

        Sodium has a large drawback: it’s a flammable metal. Imagine what would happen if Fukushima units were not water, but *sodium cooled*. Massive sodium fire is a scary thing to imagine, seriously radioactive sodium fire is much worse!

        1. “This indeed changes the picture”. I know! Cool as! Total game changer.

          ” But having a reprocessing plant and fuel fabrication facility incorporated into every unit is going to be costly”. Again, provided it is people who know what they are talking about (like Blees), when discussing costs for IFR specifically and not fast reactors generally, this should be well and truly included. But it’s a good point, and you will note that in his article Monbiot queries why the GE proposal for Britain does not seem to have this included. I wonder where they plan to conduct the reprocessing to allow themselves to actually get rid of all that plutonium they don’t want.

          “ALL sane reactor designs have negative thermal coefficient, so when stopped, they heat up, reactivity decreases, and power stabilizes. Which can be sold as “it stops automatically” – glossing over the fact that it’s not enough to stop the fission, we need to remove constantly generated decay heat.” I like the distinction of “sane”design, by which I presume you are excluding Chernobyl; agreed. But no, I am quite across what you are saying as my recent safety article with Barry Brook discusses. This is a better again. The fuel itself being a metal means the shutdown is a much simpler and more certain link; the expansion of the metal fuel pins with heat that causes the neutron leakage and depowers the reaction.

          “water or sodium makes no big difference to the “passiveness” of heat removal”. You what? Sodium:
          – Melts at 98 degrees C
          – Boils at 883 degrees C
          – At 25 degrees has a thermal conductivity (k) of 84 W/mK http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

          We are pretty familiar with the boiling and melting properties of water, but the k value at 25 degrees is 0.58 W/mK. I make sodium to be 144 times better at moving heat at 25 degrees. In a nuclear plant it can do so in liquid form at atmospheric pressure. Sodium does not need any external help to remove the decay heat indefinitely, such as, for example, a trained operator deploying a condenser. It is certainly more passive than a Fukushima era water cooled reactor, which has the added hazard of needing to be pressurised.

          “Sodium has a large drawback: it’s a flammable metal.” Indeed, which provides a design challenge, not a death blow. Given that it is also completely non-corrosive to stainless steel, a 3 cm thick stainless steel vat is a good start, with no welds or joins, open only at the top well above the level of the reactor. Blanket that top in heavy, inert argon gas. Put a second steel liner around it all, then a hardened concrete liner against the containment building, then mound earth up to the level of the top of the tank… that’s 5 levels of redundancy. One could go one. It just adds costs (which suits hardened opponents). At some point the rest of us make a call that it is safe.

          “Imagine what would happen if Fukushima units were not water, but *sodium cooled*” If only!!! They would never have melted down!!!

          1. > “water or sodium makes no big difference to the “passiveness” of heat removal”. You what? Sodium: – Melts at 98 degrees C, Boils at 883 degrees C
            > – At 25 degrees has a thermal conductivity (k) of 84 W/mK
            > We are pretty familiar with the boiling and melting properties of water, but the k value at 25 degrees is 0.58 W/mK.
            > I make sodium to be 144 times better at moving heat at 25 degrees.

            Thermal conductivity is irrelevant – the energy is transferred by liquid convenction in both cases, not thermal conduction. Sodium is used in fast reactors not because it is a better heat conductor, but because water is a moderator – can’t have that in fast reactor.

            *Passive* heat removal means “heat removal which does not require pumping”. It can be implemented both for sodium and for water-cooled reactors. Such as F1 Unit 1 Isolation Condenser…

            > I make sodium to be 144 times better at moving heat at 25 degrees.

            Besides making a mistake at looking at thermal conductivity, why do you ever think about what is the better coolant *at 25 C*? 25 C is deep cold shutdown. We need to bother primarily about having efficient cooling for high temp end of operating range!

            > It is certainly more passive than a Fukushima era water cooled reactor, which has the added hazard of needing to be pressurised.

            Wrong. IC’s in water reactors do not require pressure either.

            > “Sodium has a large drawback: it’s a flammable metal.” Indeed, which provides a design challenge, not a death blow. Given that it is also completely non-corrosive to stainless steel, a 3 cm thick stainless steel vat is a good start, with no welds or joins, open only at the top well above the level of the reactor. Blanket that top in heavy, inert argon gas. Put a second steel liner around it all, then a hardened concrete liner against the containment building, then mound earth up to the level of the top of the tank… that’s 5 levels of redundancy.

            Its all fine and dandy, but tell me, why we ALREADY had several sodium leaks and fires in sodium cooled reactors, despite having only about a dozen of them build in the whole history of nuclear industry? IOW: I don’t believe in your picture. You unerestimate both complexity of the containment, and possible failure modes in severe disaster scenarios. I tend to trust past record than market speak.

            May I suggest you (and industry in general) drop this sodium nightmare and look at its far safer sibling, lead/bismuth cooled fast reactor? I mean, WARE UP! Start taking safety SERIOUSLY!

            1. “Thermal conductivity is irrelevant”

              Denys, you serially make the error of arrogance when commenting on my site. It’s not really that it bothers me, it’s just that unless I correct you, other people take the wrong information.

              I’m not scientifically trained, so there is very little about nuclear power I “just know”. This means I have to do things like research and reading.

              On the matter of sodium as a coolant, here is a link to a 2007 presentation from Thomas Fanning of the US NRC and DOE. http://www.ne.doe.gov/pdfFiles/SodiumCoolant_NRCpresentation.pdf . That lovely little short cut CTRL F will help you find the 9 direct references to thermal conductivity, and discussion of what this property makes liquid metals attractive as coolants. While you are there, you can read about the safety advantages of operating at near atmospheric pressure unlike water cooled reactors. Here’s a quick quote from slide 8:

              “Liquid metals in general have received the most attention for fast reactor applications because of their high thermal conductivity, indifference to radiation, and useful temperature range at low pressure.”

              Another useful quote: ” Low thermal conductivity of helium results in poor heat transfer even at high coolant velocity. Cladding surfaces can be roughened to improve heat transfer (4x), but it is still 8-9x lower than for sodium.”

              Again, being a non-scientist, I am aware that the general process is called convection. Might it be that the thermal conductivity of the material influences how effectively natural convection can take place? And material with low conductivity like water (or helium) require active assistance to do the job? Active assistance that can fail?

              “Passive heat removal means…”. Ok. Passive safety means you do not need an engineered solution deployed by a trained operator to achieve the passive heat removal. Are we agreed?

              “…why do you ever think about what is the better coolant *at 25 C*? 25 C is deep cold shutdown.” Hopefully you will work out soon that I am not actually a fool. The reference I provided gave the comparison at 25 degrees. Nothing more to it than that.

              “…but tell me, why we ALREADY had several sodium leaks and fires in sodium cooled reactors, despite having only about a dozen of them build in the whole history of nuclear industry?”. In another thread, you seem both fond and forgiving of research and development for renewables. What you are talking about happens in research and development, until success is achieved, as it was with the EBR II/ IFR Prototype from Argonne National Labs. No fires there, and that is the basis of the design outline I provided.

              “May I suggest you (and industry in general) drop this sodium nightmare and look at its far safer sibling, lead/bismuth cooled fast reactor? I mean, WARE UP! Start taking safety SERIOUSLY!”. Notwithstanding points previously made to you that establish nuclear power as easily the safest major power source in the world, the link provided will give you some indications of the reason for the preference of sodium over lead. Such as:

              “Response of lead/LBE systems to seismic events will pose design challenges.
              – For medium-sized plant, one can expect primary coolant alone to weigh ~10,000 metric tons.
              – Structural design of primary system becomes a significant challenge.”

              That does not sound preferential to me, unless one’s goal is to stymie the deployment of fast reactors.

              1. Gosh. You compare liquid (sodium) to gas (helium) now? Of course liquid is a better coolant!

                > What you are talking about happens in research and development, until success is achieved, as it was with the EBR II/ IFR Prototype from Argonne National Labs.

                In fact I’m talking about Monju reactor in Japan – far more recent reactor.

                MODERATOR: No unreferenced block quotes. Please post again with a reference and preferably a link.

                > Passive safety means you do not need an engineered solution deployed by a trained operator to achieve the passive heat removal. Are we agreed?

                Yes, this sounds right.

                However, reactor vessel filled with sodium is no different than reactor vessel filled with water in this regard. They behave similarly after they are scrammed: they will heat up from decay heat – the whole thing: fuel, coolant, reactor walls… If heat is not removed by an external system, they both will have their fuel melted, rector vessel breached, etc. MODERATOR: Please provide a supporting reference to these statements. You are stating these points as fact. They are contrary to other references that have been provided

                In this case, reactor with water has the problems of high pressure rise with temperature, and risk of Zr/steam reaction at about 700 C;

                reactor with sodium has the problem that escaping overheated coolant is very likely to ignite MODERATOR Please provide a supporting reference for this statement. It is contrary to other references that have been provided –

                and putting out sodium fire is very difficult. MODERATOR Please provide a reference for this statement relevant to its use as a coolant in a nuclear reactor.

                Lead/bismuth reactor has none of these problems! Of course it can melt down too, but leaking coolant won’t ignite.

                And again: all types of reactors need a system to remove heat. Fast reactors have no advantage here. MODERATOR Please provide a reference for this statement. It is contrary to other reference that have been provided indicating a clear advantage to the use of liquid metal coolants.

                1. It’s New Years Day, which I would rather spend with my family, so I will make a response to this in a couple of days.

                  In the meantime, please see my comments as moderator and tidy things up a bit so that the discussion can progress.

                  I will not run comments that make claims as though fact without sufficient support, most especially in areas like Generation IV nuclear which are quite new for many people.

                  You will note my comments have provided references to information and always do so for direct quotes, normally with directions to page numbers. Please do the same. Nuclear power is an important issue and the area is full of misinformation. References are the primary quality control, and they are a requirement at DSA. Otherwise the site becomes useless.

                  Similarly, your statement several posts ago that “thermal conductivity is irrelevant” would appear to be completely off the mark on the basis of a very solid reference. Would you please acknowledge this point so that the discussion may progress? Would you also please read that reference in detail, as it is squarely on the topic of discussion and comes from the most authoritative source possible? If you wish to disagree with it here, you will need to provide references to support your disagreement.

                  1. You seem to be missing my point. Let me try again.

                    My point is that fast reactors are useful and needed – for one important reason, they can efficiently burn any actinides, unlike thermal spectrum reactors, which can efficiently burn only fissile isotopes. This is important primarily because we want to use U-238 and thorium, and secondarily because we want to get rid of transuranics.

                    But fast reactors are more difficult machines than thermal ones. That’s why thermal reactors were built sooner and in larger numbers. To develop and build fast reactors, a lot of money is needed. Therefore, naturally, nuclear industry tries to “sell” this idea, and they, naturally, are using market-speak and blow any tiny possible advantage of fast reactors out of proportions, to the point where their claims come dangerously close to being outright lies.

                    You swallowed a lot of those invented advantages. For example, liquid sodium coolant is NOT better than water – otherwise we’d be using it in thermal reactors too, right? We don’t do that. Ask yourself – why not?

                    To enumerate the problems: it’s more costly, it’s harder to purify (an operation which needs to be constantly performed on primary loop), it’s flammable, and it’s non-transparent, which makes fuel loading/unloading ops significantly harder. It has better thermal conductivity, yes, but it is of no practical advantage, because water is already good enough.

                    The ONE single reason sodium or lead is planned for fast reactors is that fast reactors must not have good moderating materials inside them, which makes water much less suitable for them than for thermal ones. The rest is “marketing”, also known as creative half-truths.

                  2. Well, my point at this stage of our engagement is that you need to provide references for your statements, as to date your record for accuracy and understanding of the matters under discussion is not very strong. Please accomodate that reasonable request to maintain the integrity of the site and this discussion. More from me when I have time.

  4. There’s some confusion above on the roles of convection and conduction in heat transport. High thermal conductivity does have a big effect on heat removal, but perhaps not for obvious reasons.

    The greatest rate of temperature change, and therefore the highest rate of heat movement, occurs in a very thin film of liquid at the surface of the hot fuel rod, called the thermal boundary layer. For a coolant like water with low thermal conductivity, the thermal boundary layer is very thin, smaller than the length scale of turbulence within the fluid, and transport throughout he boundary layer is entirely by conduction, and therefore slow.

    But for a coolant like sodium with high thermal conductivity, the thermal boundary layer is thicker. Its larger than the length scale of turbulence, so for these fluids heat can be removed by convection from within the thermal boundary layer. This is much faster than if heat could only escape from the boundary layer by conduction.

    So in short, thermal conductivity is important because it determines whether or not convection can play a role in removing heat at the surface of the fuel rods. And high thermal conductivity has a big effect on the rate of heat removal, because it “switches on” convective heat removal.

    This is actually described on page 46 of the document Ben references, though it may not be comprehensible to the lay reader.

  5. Denis Vlasenko, at 9.32 am Jan 2 above,

    Your points about fast reactors being useful for actinide burn up, and liquid metals having good neutronic properties, are correct. Your other points regarding nuclear industry motivations, and marketing, are hogwash.

    Fast reactors are needed because they can access about 99.5% of the energy in uranium, rather than just the ~1% efficiency of the current generation of reactors. This is necessary to secure the world’s energy supply into the far future without precipitating a climate disaster.

    The ability of fast reactors to burn up actinides is highly desirable. But it would not in itself justify development of the technology. To repeat, the driver behind fast reactor development is to secure sustainable energy and a habitable planet.

    You can’t say fast reactors are more difficult machines. Thats too great a generality, you can only talk about particular designs. The IFR design is simpler than just about any other reactor design. If we are talking about fast reactors that, in the view from the beginning of 2012, we want to build, they are simpler and easier than the alternatives.

    They should also be cheaper. There are a number of reasons for this, such as: they operate at atmospheric pressure, not high pressure, so they don’t need to be nearly as big; the cores are much more compact; overall plant size is much reduced, meaning less concrete, less steel, less land, less time spent in construction; the smaller size also means smaller components that can be built on assembly lines in factories and are therefore cheaper. These should all drive the cost down relative to much larger conventional reactors.

    Thermal reactors were built sooner and in larger numbers because they leveraged off existing knowledge of materials and design rules – we had a lot of data on water and steam in the 1950s, and much less on liquid metals. Light water reactors worked and we worked out pretty quickly how to build them. Thats why they were built.

    The money required to develop fast reactors, or at least the IFR, has already been spent. We now know how to build them. In this post George Monbiot describes GE’s money back offer to build one in the UK – if it doesn’t work, there’s no charge. That’s an expression both of the maturity and readiness of the technology, and of the cost to build it.

    You say liquid sodium is “NOT” better than liquid water. It is. I explained why in some technical detail in my post above, which I think described important details you were unaware of. Your emphatic assertion on this point is inappropriate given your superficial understanding of the physics. You describe the thermal properties of liquid metals as an “invented” advantage, but they are real advantages that enable vastly superior reactor designs.

    You list problems – cost, purification, opacity and flammability. At $3400 per cubic metre for reactor grade sodium the cost is an insignificant component in the reactor cost. Purification in a cold trap is simple. Opacity does not create any problems, thats a very anthropocentric view of process monitoring. Flammability is a property readily controlled by design and engineering controls, as is already done in many industries already handling liquid sodium in bulk (allow me to cite the example of the sodium-sulfur batteries beloved of the antinuclear renewable advocates). None of these items on your list are of any consequence.

    You say Ben has swallowed invented advantages from half truths and creative marketing that are close to outright lies (all your words). Why should I believe you?

    I’ve watched this discussion over the last week or so and you demonstrate a superficial understanding of the topics under debate – the reactor physics, the thermal characteristics, the development history, the actual safety record and risk profile, the economics of the nuclear power and the drivers of future development, the desperate need to displace fossil fuels and the debilitating limitations of the non-nuclear alternatives. I see mud blindly thrown against a wall to see if something sticks. When it doesn’t you just move on to the next line of attack without showing any sign of integrating new knowledge into your understanding.

    In contrast, the process whereby Ben draws his conclusions is clear to me, and is driven by a commitment to go where the facts lead in pursuit of a solution to the climate crisis, certainly not by “swallowing marketing lies”. Your suggestion to that effect is insulting, and an apology would not be inappropriate.

    1. > Fast reactors are needed because they can access about 99.5% of the energy in uranium, rather than just the ~1% efficiency of the current generation of reactors…
      > The ability of fast reactors to burn up actinides is highly desirable. But it would not in itself justify development of the technology.

      If I wasn’t clear, then I clarify: U-238 is an actinide too. Thus, I do understand (and support) the need to have fast reactors in order to burn actinides, *primarily* U-238. I even said so before in this thread: “This is important primarily because we want to use U-238 and thorium, and secondarily because we want to get rid of transuranics.”

      > You say liquid sodium is “NOT” better than liquid water. It is.

      Why it is not used in thermal spectrum reactors then? Go and propose to CANDU peopl to replace water in the tubes with sodium. LOL 🙂 I can imagine their reaction!

      > Opacity does not create any problems, thats a very anthropocentric view of process monitoring.

      What about loading/unloading fuel? Especially if something goes not exactly according to plan – such as things falling into the reactor vessel? This does happen (go to allthingsnuclear.org and read quite a few stories). Is it trivial to find and fish them out of sodium?

      > Flammability is a property readily controlled by design and engineering controls, as is already done in many industries already handling liquid sodium in bulk.

      Do they handle many tons of radioactive superheated sodium?

      > None of these items on your list are of any consequence.

      And Japan reactors are safe. After all, it’s unthinkable that Japanese would wastly unerestimate possible thunami height. And unthinkable that they wouldn’t have any manuals what to do in extended SBO. Can’t be! Neither it is thinkable for Japanese to have sodium leaks in their first fast reactor. Can’t be! RIGHT?

      People like you will only be convinced when confronted with actually happening disaster. You really won’t believe fast reactor sodium file is possible, and awful, until it happens.

      1. I’m happy to leave it to John or others to continue to make responses if they wish.

        BUT

        Denys, these threads are useful for exploring issues with others, like for example, opacity as you raise above. That’s how we learn.

        However there is NO NEED to continually make your posts with the degree of sarcasm, arrogance and occasionally outright aggression that have characterised most of your comments to date.

        I am quite aware that the internet in general is the wild west of human interaction, but its not like that around here. If you want to keep coming back, start lifting your game or I will simply put you on forced moderation.

        These rules apply to everyone but rarely have I needed to spell them out. Stick to the issues, don’t attack the people, concede your errors so that discussion might move ahead, make you points clearly and if you have a strong point of disagreement, PROVIDE REFERENCES AND LINKS. Thinking people use this site, and evidence is king.

      2. >Why it is not used in thermal spectrum reactors then? Go and propose to CANDU peopl to replace water in the tubes with sodium. LOL 🙂 I can imagine their reaction!

        Huh? CANDU has a completely different design. The wit of your sarcasm is lost, it’s like saying that jet planes should use diesel over avgas. Sodium has different properrties to superheated water, it is managed differently.

        >What about loading/unloading fuel? Especially if something goes not exactly according to plan – such as things falling into the reactor vessel? This does happen (go to allthingsnuclear.org and read quite a few stories). Is it trivial to find and fish them out of sodium?

        How on earth would something ever fall into a reactor vessel? the probability would surely be vanishingly small (though I bet there’s an estimate somewhere).

        >Do they handle many tons of radioactive superheated sodium?

        many tons, yes. superheated, yes. Radioactive? well it’s already remotely handled so shielding is a relatively trivial concern. All uranium is remotely handled, it’s what they do already.

        >And Japan reactors are safe. After all, it’s unthinkable that Japanese would wastly unerestimate possible thunami height. And unthinkable that they wouldn’t have any manuals what to do in extended SBO. Can’t be! Neither it is thinkable for Japanese to have sodium leaks in their first fast reactor. Can’t be! RIGHT?

        Japan knew within a few year sof building Fukishima that they had a dud. This was on the very of out of date when it was commissioned. it was slated for retirement, Did you note how all the other reactors on site and nearby functioned perfectly well? o

        But remind me, what’s the death toll due to radioactivity so far, and estimated? Two? Compared to up to 25 000 deaths due to the tsunami itself. And I’ll bet that japan’s thermal coal industry has had more tahn two deaths in the subsequent nine months.

        for a=

  6. “many tons, yes, superheated, yes”

    In the case of the IFR the sodium is not, strictly speaking, superheated, it’s just hot.. That is, it is not heated to above its natural boiling point of 883 C at atmospheric pressure and then confined in a pressure vessel as a superheated liquid. That’s one of the key advantages of the IFR, that no pressure vessel is required.

  7. wilful: “Japan knew within a few year sof building Fukishima that they had a dud.”

    I hadn’t heard that. Could you expand?

    “But remind me, what’s the death toll due to radioactivity so far, and estimated? Two?”

    I thought it was zero. Am I wrong?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s