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The paper I will discuss in this brief diary is in the "ASAP" section - as of this writing - of the scientific journal Environmental Science and Technology, a publication of the American Chemical Society.

It's all about the relationship between things that are closely related, as it turns out (possibly in more ways that I will overtly describe), an extremely radioactive species, the element Radon and carbon dioxide.

The paper is here:   Coupling Automated Radon and Carbon Dioxide Measurements in Coastal Waters.

Lest anyone start in, as usual, in fits of fear, ignorance, and superstition to blame the nuclear industry for the presence of, um, highly radioactive radon in water as described here, I would suggest that they may have more to fear from their pals in the gas industry, for which the so called "renewable" industry serves as a fig leaf.   Excerpts from this paper are in the text below and should - unless one has joined Greenpeace and is thus unwilling to read anything that comes from a source in the primary scientific literature - put to rest any claim that radon in water has much to do with nuclear energy.

Radon, for the record, is widely considered from an epidemiological perspective to be the second largest cause of lung cancer on earth, after tobacco smoking.   (The third largest is almost certainly air pollution:   A definitive link between lung cancer and diesel exhaust has recently appeared in the literature.)

As it happens, people where I live all face a problem with Radon, and for sure, the ill thought out, ill considered decision to shatter permanently and forever, all of the shale in this area will definitely and unequivocally result in higher radon flows forever.

From the paper:
Very little is known about the role of groundwater in delivering carbon to surface waters.1 Dissolved organic and inorganic carbon concentrations in groundwater are often much higher than those in surface waters. Therefore, groundwater seepage may play a significant role in carbon budgets in freshwater and marine ecosystems even if the volumetric contribution is small. In river systems, some of the base flow seepage is automatically included in downstream river carbon measurements.1 In marine and estuarine systems, however, site specific measurements are needed to resolve the contribution of submarine ground water discharge (SGD) to carbon budgets. The modern definition of SGD includes both a terrestrial (freshwater) and a marine(recirculated seawater) component.2 While fresh groundwater is a source of “new” water and carbon, recirculated seawater can be a source of “recycled” organic matter respiration products such as nutrients and carbon dioxide.3,4Recent technological advances (i.e., automation5) have increased our ability to assess groundwater discharge in complex systems using natural tracers such as radon (222Rn, half-life = 3.84 days). Radon is a biogeochemically conservative noble gas and a member of the 238U decay chain.6 Since uranium is present in nearly all sediments and has a half-life of billions of years, any water that remains in contact with sediments for at least several hours acquires a radon signal.
The bold is mine, but let me repeat that, in case you missed it:  "Since uranium is present in nearly all sediments and has a half-life of billions of years, any water that remains in contact with sediments for at least several hours acquires a radon signal."

In my polls, which are often more popular than my diary texts, I sometimes like to give a poll choice that involves "banning uranium."  

This is a joke.    As I noted in other places (most recently in a diary called How Radioactive is the Ocean?), the oceans on this planet contain about 5 billion metric tons of uranium.    This is not all the uranium that there is on this planet, but only represents the amount that can be dissolved in seawater.   If one were to remove this uranium from the ocean, it would recharge from the earth's crust, including crustal land rocks.

But I like to tempt anti-nukes to ban the earth's crust.   They're so cute when they do that.

The only way to get rid of uranium (and thus radon with which it is always in radioequilibrium) is to fission it in nuclear reactors.    Fissioning uranium actually reduces the number of radioactive decays that uranium must go through to become nonradioactive (in the form of lead).   Also most of the fission products, when they reach the ground (non-radioactive) state are less toxic than lead.    For instance one fission product is the element cerium, which is widely used in making self cleaning ovens and lots of other stuff with which you may be familiar.

An attempt to fission the 5 billion tons of uranium in the uranium would involve the generation of about 400 million exajoules, or about 80% of 750,000 years of human energy consumption as of this writing, which is currently at about 520 exajoules per year.   However, again, the attempt to remove this uranium from the oceans would necessarily fail, since, as soon as it is removed, more (from the crust and mantle) dissolve.

Anyway, to return to the matter of CO2 and uranium, the paper says:

The radon and the carbon dioxide scientific communities have evolved independently in the last several years. Several radon investigations evoke the carbon cycle to justify the need for studying groundwater surface water exchange,3 and several carbon cycle investigations put groundwater discharge in the“to do” list.9,14,15 In addition, much of the groundwater community has focused on modeling studies from a water resources rather than a carbon cycle perspective. In this paper, we contribute to bridging the gap between these communities by demonstrating that automated, high precision, high-resolution radon and carbon dioxide measurements can be easily performed simultaneously using portable gas detectors. We report the results of laboratory experiments designed to assess the performance of six gas equilibration devices and the first coupled, automated 222Rn-pCO2 field measurements.
The paper goes on to show that indeed, radon and carbon dioxide concentrations in a particular area are, in fact, correlated, and since the radon can only come from ground water, the method represents a way of measuring carbon flows from ground water.

The flow of carbon dioxide in groundwater would, in theory, be relevant to studying the leach rates from all those silly carbon dioxide sequestration fields that people, including some anti-nukes, are always talking about.   In their lexicon, a few tens of thousands of tons of used nuclear fuel, consisting largely of wholly insoluble materials cannot be stored for a few million years, but hundreds of billions of tons of a highly soluble gas can be stored, for eternity.

Life is so bizarre sometimes.

Anyway.    I live in Western New Jersey, at the edge of the large geological feature known as the Reading Prong, which is a natural uranium formation.   My basement does have radon in it:  I've measured it, using kits supplied by my town government.  

Shattering rocks, as the gas companies are doing with lots of cheering from the peanut gallery, to "frack" for gas - increases the available surface area for equilibrium radon to leak from these rocks.   When the gas is gone, as the half-life or uranium is about the age of the earth - 4.5 billion years - the radon will continue to leach:   Forever.

Similarly the dangerous fossil fuel waste that is released by burning the fracked gas will probably also remain essentially forever, or at least until the climate in which you and I were born is no longer recognizable.

But don't worry:   Be happy.   It's "economical."

The only way to stop radon leaching from shattered crustal rocks beneath New Jersey, Pennsylvania and New York will be to remove the uranium and fission it.

That probably won't happen though, because, of fear, ignorance and superstition.

It's been a pleasure to chat with you all.   Have a nice day tomorrow.

Originally posted to NNadir on Wed Jun 27, 2012 at 07:04 PM PDT.

Also republished by SciTech and Nuclear dkos.


Well, should we ban uranium, well, should we?

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Comment Preferences

  •  Thanks for the information (6+ / 0-)

    It's gratifying to see knowledge being spread into the netosphere.  Perhaps it will seep into our gray matter like uranium seeps into our ground water and those humans will acquire a wisdom signal.

    Perhaps not.  What is the half life of elemental knowledge?

  •  I like your point about fracking (6+ / 0-)

    More surface area releases more of all gasses trapped within.

    I vote we stop messing with Mother Nature's packaging of toxic materials. She put them away that way for a reason.

    She had a great solution for sequestering methane in the permafrost, excess carbon in the oil shale, and the brilliance of mixing the u238 with the u-235...

    Here is the question that I think should be asked every time we find a new way exploit some natural resource:


    Answer that...every time.

    Another flaw in the human character is that everybody wants to build and nobody wants to do maintenance. Kurt Vonnegut Economic Left/Right: -7.50 Social Libertarian/Authoritarian: -6.10

    by ToKnowWhy on Wed Jun 27, 2012 at 11:34:49 PM PDT

  •  I nominate this diary for the Madame Curie (6+ / 0-)

    Golden Lab Assistant Award.

    Enjoyed the diary and science.

    The labor of a human being is not a commodity or article of commerce. Clayton Act, Section 6.

    by Ignacio Magaloni on Thu Jun 28, 2012 at 12:27:30 AM PDT

  •  What is the EROI (1+ / 0-)
    Recommended by:

    of seawater uranium extraction and re-use?

    •  Hmmmm.... (4+ / 0-)
      Recommended by:
      gzodik, kbman, jim in IA, palantir

      Here is something from nuclear green web site:

      The Cost of Recovering Uranium from Seawater

      A Japanese report, Recovery System for Uranium from Seawater with Fibrous Adsorbent and Its Preliminary Cost Estimation, Takanobu Sugo, Masao Tamada, Tadao Seguchi, Takao Shimizu, Masaki Uotani, and Ryoichi Kashima has translated into English by The Analytical Center for Non-proliferation. The report, first published in the Japanese Journal Nihon Genshiryoku Gakkaishi, discussed the Japanese methods of recovering uranium from sea water. (Also continued here.) Much of the information in this Japanese report is startling and even amazing.

      The report states:

      "At the Takazaki Radiation Chemistry Research Establishment of the Japan Atomic Energy Research Institute (JAERI Takazaki Research Establishment), research and development have continued for the production of adsorbent by irradiation processing of polymer fiber. Adsorbents have been synthesized that have a functional group (amidoxime group) that selectively adsorbs heavy metals, and the performance of such adsorbents has been improved. Uranium adsorption capacity of this polymer fiber adsorbent is high in comparison to the conventional titanium oxide adsorbent. We have reached the point of being able to verify the attainment of 10-fold higher adsorption capacity on a dry adsorbent basis. This adsorbent can make practical use of wave motion or tidal power for efficient contact with seawater. This adsorbent has been used since 1996 in the actual marine environment by utilizing moored small-scale test equipment for recovery of trace metals, including uranium, from within seawater. As a result, it has become apparent that use of this adsorbent makes possible recovery of seawater uranium with higher efficiency than the earlier method."


      A recovery system based upon this adsorbent uses ocean current to produce efficient contact between the adsorbent and a large volume of seawater. According to the basic conditions of Table 1, the required quantity of adsorbent (quantity at the time of mooring) becomes 40,000 tons, and the quantity exchanged due to adsorbent performance decline becomes 10,000 tons per year.

      Adsorbent is used in the form of 15 cm wide strips of nonwoven sandwiching a spacer and coiled into a short cylindrical shape. This roll is loaded into a cage (adsorption bed = short cylindrical shape of 4 m diameter) as shown in Figure 4. A single adsorption bed is loaded with 125 kg of adsorbent. The quantity of adsorbed uranium per bed during 60 days is 750 g. These adsorption beds are strung and tied together by rope at roughly 0.5 m intervals to form 1 basic unit.

      125 kg of adsorbent is loaded into a single adsorption bed. Specifically, the adsorption bed is a metal mesh container (cage), formed from stainless steel, that has specific a gravity of 7.8 and a mass of 685 kg. A 15 cm wide sheet of adsorbent (150 g/m2) is coiled so as to load 125 kg of adsorbent. A plastic mesh sheet is inserted between adsorbent windings as a spacer. The specific gravity thereof is 1.15 so total mass is 104 kg. Total bed mass becomes 914 kg. The weight in seawater becomes 611 kg, so the weight when pulled up becomes 1,161 kg.


      Although 40,000 tons of adsorbent must be produced beforehand prior to the start of uranium recovery, production then becomes 10,000 tons per year for replenishment during the time period of regular uranium recovery. We made a trial calculation of the cost of manufacture of 10,000 tons per year of adsorbent. Details of this calculation are shown in Table 2. Precursor material cost occupies a large proportion in comparison to production equipment cost. Even if we were to assume an increase in production equipment for annual production of 40,000 tons per year, the equipment cost increase would be held down to slightly more than 2-fold. From such estimates, production unit cost of adsorbent was estimated to be 493,000 yen per ton (493 yen/kg). The quantity of recovered uranium becomes 120 kg per 1 ton of adsorbent for the case of 20 reuses. Therefore the adsorbent production cost required for recovery of 1 kg of seawater uranium is estimated to be 4,100 yen/kg-U.

      The most interesting aspect of this report is the cost of this radical recovery method. The report states. "The recovery cost was estimated to be 5-10 times of that from mining uranium. More than 80% of the total cost was occupied by the cost for marine equipment for mooring the adsorbents in seawater, which is owning to a weight of metal cage for adsorbents. Thus, the cost can be reduced to half by the reduction of the equipment weight to 1/4. Improvement of adsorbent ability is also a problem for future research since the cost directly depends on the adsorbent performance."

      Would the Japanese sea water extraction technic make nuclear power too expensive? Not at all. The cost of nuclear fuel is only a minor part of the expense of nuclear generated electricity. And since alternative technology can extract 130 times as much energy from nuclear fuel as is being extracted now, consumers potentially won't notice the difference on their power bills.

      Different methods of mooring the absorbents were investigated by the Japanese, and the cost of each estimated. The Japanese estimate that it would cost between 30,000 and 56,000 yen to recover one Kilogram of uranium from sea water. At the current exchange rate the yen is pegged at a little more that 100 per dollar. So the recovery cost would be between $250 and $135 a ton. The Japanese, in 2001 stated that they planned more research directed at lowering materials input,and increasing the efficiency of the process.

      Spot Market prices for uranium, which had been as low as $7.00 a pound in 2000, peaked at $136 a Pound in June 2007. current prices range from $70 and $75 per pound, and prices are expected to rise to the $100 to $110 range during the next two years. Clearly as new reactors begin to come on line, the price of Uranium will rise to the point where sea water recovery of uranium will be economicallty viable.

      How long can we keep extracting uranium from the see? There are approximately four and a half billion tons of Uranium in the see. If you are worried about that running out, Jim Muckerheide has an interesting observation: "The consistent 3.3 ppb U in seawater is in chemical equilibrium. If it were being depleted, we would expect that additional U would be leached and put in solution from ocean bottoms, hydrothermal vents and cold seeps, and terrestrial sources (primarily through tidal pumping on the continental shelves, with some from rivers and other discharges). If we extracted a billion tons over hundreds of years, it is more likely that the oceans will contain nearly 4.5 billion tons than be reduced to 3.5+ billion tons."

      Jim then asked: "Is this a "renewable" energy source?"

      It appears so. Estimates of the amount of uranium in the earth's crust is 40 trillian tons. If Jim Muckerheide is correct there is a chemical equilibrium between crustal uranium and uranium in the sea. Since the amount of uranium in the sea is a tiny fraction of the ammount of uranium in the crust, the uranium supply in the sea will keep on replenishing as long as the earth lasts.

      Dr. Isaac Asimov: "The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny ...'"

      by davidwalters on Thu Jun 28, 2012 at 07:57:34 AM PDT

      [ Parent ]

    •  It can be shown that the uranium and thorium... (4+ / 0-)
      Recommended by:
      kbman, jim in IA, palantir, billmosby

      ...already mined can supply all of human energy needs - assuming (and maybe not justified) that human energy demand stabilizes at around 500-600 exajoules per year for at least several centuries.

      This assumes the use of Pu-239/Pu-241 and U-233 intermediates, a matter which is technically trivial at this point.

      So in some sense the question is immediately irrelevant.

      It can also be shown that any reactor that uses water cooling from sea water will draw enough water to accumulate - using relatively primitive amidoxime resins - recover, as a result of cooling water flows about 1/4 of the uranium that it consumes.

      In the case where humanity is using nuclear power to desalinate water - something about which I am distinctly ambivalent at best - these values rise.

      I oppose fracking, but I do not expect that anything will be done to stop it.

      In this case, it may well prove possible to use schemes like in situ leaching to recover uranium from dead fracked gas fields, and as a side product, actually sequester some of the dangerous fossil fuel waste carbon dioxide as a side product.

      But again, it's irrelevant.   One of the more attractive aspects of nuclear energy - the fear, ignorance and mysticism of its opponents notwithstanding - is that it is the only means of banning all energy mining of all types - including lanthanide mining - in the relatively near future.

      •  sorry, I thought you made it relevant (0+ / 0-)

        when you stated:

        An attempt to fission the 5 billion tons of uranium in the uranium (sic) would involve the generation of about 400 million exajoules, or about 80% of 750,000 years of human energy consumption as of this writing, which is currently at about 520 exajoules per year.  
        I was just curious if the extraction of uranium from seawater was an energy positive process or do you have to put more energy into the system to extract the uranium than the uranium would provide.
        •  No. I was being sarcastic, as usual. (0+ / 0-)

          I was making fun of uranium fear.

          It would be impossible for humanity to consume all of the uranium in the ocean, so those people who have an irrational fear of the element are best advised never to swim in oceans or in places like Lake Mead.

  •  I have doubts this will happen any time soon. (3+ / 0-)
    Recommended by:
    gzodik, NNadir, palantir
    The only way to stop radon leaching from shattered crustal rocks beneath New Jersey, Pennsylvania and New York will be to remove the uranium and fission it.
    Pricey and what a mess it would make. Nimby nimby nimby.

    I voted for the Kong.

    So...are there any current studies of CO2 in groundwater by using the Radon measurements? Or, is it only proposed by the paper?

    Universe started with a Big Bang. It's big, getting bigger, and mostly dark.

    by jim in IA on Thu Jun 28, 2012 at 06:52:30 AM PDT

    •  Were this to take place, it need not be any... (2+ / 0-)
      Recommended by:
      jim in IA, palantir

      ...more messing than fracking itself, since it can take place with liquid (or supercritical) carbon dioxide as a solvent using what is known as an ISL scheme.   (In situ leaching.)

      However, as I noted above in another comment, the amount of uranium and thorium already mined should be sufficient to provide humanity's energy needs for many centuries to come.

      The only reason to leach this uranium then, would be to clean up the fracking mess.

  •  Hmm, Uranium as a renewable resource... (1+ / 0-)
    Recommended by:

    I am presently reading a book called "Plentiful Energy" about the old IFR project, written by a couple of my old bosses (Chuck Till and Yoon Chang). Till speculates there that the IFR fuel efficiency and recycle process would possibly be able to allow utilization of that uranium in seawater that you speak of. I wonder...given the amount of U in that form and the more or less steady recharge rate, would that energy source possibly last longer than the sun? Of course after the sun flares up it would be kind of moot I suppose.

    That book was published in 2011 and was more than a trip down memory lane for me, it also detailed a lot of experimental results in the area of fuel cycle system characteristics (a chemist such as NNadir would probably be interested in the details therein) and also in the area of extreme fuel melt- or more like fuel explosion- accidents in which the merits of relatively low melting point metal fuel were explored. Also, the rationale behind claims of proliferation resistance was explained more fully than I had seen before. Lots of other interesting stuff there as well.

    Moderation in most things.

    by billmosby on Thu Jun 28, 2012 at 07:58:05 PM PDT

    •  Supposedly, the world inventory of depleted (1+ / 0-)
      Recommended by:

      uranium is on the order of 1.2 million tons.

      Ignoring neutrinos - as one should - the fission of an atom of plutonium (made from this plutonium) yields about 190 MeV, suggesting, with a few back of the envelope calculations that the energy value of this uranium is about 92,000 exajoules of recoverable energy.

      This is enough to meet current word demand - without burning a single carbon atom - for about 200 years.

      But then there's thorium, present and already mined and dumped as a side product for the lanthanide industry.

      In many ways - although one will find partisans for all of one or all of the other - the thorium cycle and the plutonium cycle offer many very nice synergies, particularly because the vast majority of our existing nuclear infrastructure consists of thermal spectrum reactors.

      It will be a long time before anyone will need the uranium from seawater, although it is there when necessary.
      I will say this:   The chemistry of fuel recycling is undergoing a burst of creativity, particularly with the development of very, very, very exciting solvent systems, which are almost entirely free of petroleum bases.

      In many ways too, I will say that recent advances in materials science probably mean that the old approaches to fast reactors are already obsolete.    

      I just can't believe the stuff I'm reading these days.

      I will try to pick up that book if I can find it around though.   I find many papers and references from the "good ole' days" that are fascinating and offer considerable insight.

      •  It's self published through the CreateSpace (1+ / 0-)
        Recommended by:

        subsidiary of Amazon. I got my copy there for the low $20s. Oh, here it is...

        Have you ever looked into the electrorefining process that Argonne used in their IFR research? The book goes into that pretty thoroughly. Basically it's a cadmium and salt (LiCl and something, I forget, else) system with electro.. transport? thrown in. They're still running it today, putting the EBR-II spent fuel inventory into forms suitable for some repository, if any. Or for use as fuel, whichever comes first.

        Moderation in most things.

        by billmosby on Thu Jun 28, 2012 at 09:32:37 PM PDT

        [ Parent ]

        •  Thanks, Bill. (1+ / 0-)
          Recommended by:

          I have spent lots of time reviewing electrochemical pyroprocessing methods in various places in the literature.

          This is another area where there is really a lot of active work, particularly with respect to the development of ionic liquids with large electrochemical windows.

          I've played around - only on paper - with neat modifications to these strategies.

          It would seem to me that there are lots of hybrid procedures that might work very well.

          I didn't know they were still running those methods.   That's a good thing, I suppose, so long as no one tries to throw the plutonium away.

          Thanks again.

          •  Luckily, there's (0+ / 0-)

            no place to throw it away, for now. I wonder how many decades (centuries?) until there is, lol. It occurs to me that plutonium is a wonderful resource for a lot of people, not least those who love to use it as a whipping boy. Nope, I'd say it won't be going anywhere for quite a while.

            Moderation in most things.

            by billmosby on Fri Jun 29, 2012 at 02:13:53 PM PDT

            [ Parent ]

          •  OH, and (1+ / 0-)
            Recommended by:

            they've only actually tried extracting the Pu at lab scale, because as Till tells it anyway you have to draw the U concentration in the electrorefiner down quite a ways to get the Pu to come out at the liquid cathode. The process worked as expected. You get some percentage of U with it ( I want to say 10 or 20 percent), and the other actinides too. Which is one thing that makes the process unsuitable for making weapon material. I hope I haven't mangled that too much, I only read it once and I am about as far from being a chemist as is imaginable.

            Moderation in most things.

            by billmosby on Fri Jun 29, 2012 at 02:17:59 PM PDT

            [ Parent ]

            •  I have a neat approach to separating U (1+ / 0-)
              Recommended by:

              from Pu and the higher actinides in these kinds of systems, based on some very obscure chemistry I found from the middle of the last century, but it's probably not applicable to metal fuels.   It's very esoteric.

              The higher actinides do pose some interesting physics problems when burned together with plutonium.

              Plutonium itself requires special physics treatment.

      •  OH, yes... the IFR people used to like to (1+ / 0-)
        Recommended by:

        quote that about DU. They talked in terms of running the U.S. and I remember numbers like 4000 years or so. Of course that was 30+ years ago, energy consumption may have gone up. Or perhaps that figure was just for the portion that goes into electricity. Time files, memories fade...

        Moderation in most things.

        by billmosby on Thu Jun 28, 2012 at 09:35:15 PM PDT

        [ Parent ]

        •  Spent fuel stocks (2+ / 0-)
          Recommended by:
          NNadir, billmosby

          Focussing down on just spent fuel, how much conventional or MOX reactor fuel could be made from, say, the 70,000 tonnes or so of spent fuel in the US stockpile assuming reprocessing? I've never seen real numbers on the residual U-235 enrichment levels of spent fuel when it is removed from a reactor during refuelling operations but I've been assuming it would be at least 2% or so. There's also the unburnt Pu-239 and Pu-240 which remains in the fuel pellets after fission stops hence my reference to MOX.

          •  Typical figures are about 1% plutonium and... (1+ / 0-)
            Recommended by:

            residual enrichments between 1 and 2%.

            These are reasonable working figures.

            The DUPIC cycle uses residual enriched uranium directly in CANDU type systems.    It is most advanced in Korea, and in my view should be used internationally.                                          

            MOX is being used in many countries.   One of the destroyed Fukushima reactors was running on it as I recall.

            Unfortunately modern fuel cycles have long cooling periods during which some of the very valuable Pu-241 is allowed to decay to less useful Am-241.

            One would hope that more modern fuel cycles will be piloted and commercialized.

          •  IFR folks would say there are 70,000 tons (1+ / 0-)
            Recommended by:

            of fuel there, as passing the entire mass of spent fuel through the IFR multiple times would turn all the U into Pu and higher actinides over time and thence into fission products.

            And it wouldn't take all that many passes as the IFR fuel was demonstrated to be good for about 20% burnup per cycle.

            Moderation in most things.

            by billmosby on Fri Jun 29, 2012 at 02:31:34 PM PDT

            [ Parent ]

            •  Wasn't there some talk of Zr alloys of Pu? (1+ / 0-)
              Recommended by:

              The idea was simply to destroy the Pu without getting any breeding value.

              Or do I have the wrong program in mind?

              This of course would be a bad idea, since future generations will need that breeding capacity.

              •  IFR fuel, or really the later EBR-II fuel (1+ / 0-)
                Recommended by:

                was 90% U, 10% Zr, to get the melting point up when Pu had bred in. I think it may also have improved the swelling performance.

                I was writing another response to you about U-Pu-higher actinide separation when it seemed to disappear. What I said was that the IFR process didn't separate Pu and higher actinides from each other or from U, it was run to produce a given fissile loading of U 235, Pu, and higher actinides. As well as U-238, of course.

                The neutron spectrum with sodium coolant and metal fuel is hard enough that Pu and higher actinides all look about the same as far as fission cross section is concerned. Leaving them all in the fuel or electrorefiner keeps the material about as suboptimal for weapon use as possible, and the reactor eats it just fine.

                The situation with oxide fuel is not too bad, but the softer spectrum makes the use of higher actinides a bit different, they build up to higher concentrations over a number of cycles or something.

                The rest of the fast reactor folks went to oxide when the early EBR-II metal fuel seemed unable to get beyond a few percent burnup. Argonne's role as a fast neutron irradiation facility gave them a decade or two to experiment with metal fuel and they hit upon the solution- give the fuel some room to grow and eventually the fission gas bubbles that makes it swell interconnect and provide a pathway out of the fuel and into the fuel pin plenum. For a thermal bond, they put enough sodium in the fuel pin to bridge the gap.

                I think the Zr was added partly to enhance some aspect of this performance, and also to get the melting point up for fuels containing significant Pu.

                Metal has the advantage that it doesn't react with the sodium coolant the way oxide does. They ran EBR-II with intentionally breached elements and found that the fission products and everything else stay put in the elements and don't crap up the coolant. (for EBR-II, "element" = fuel pin, and "subassembly" = what some call fuel elements or bundles elsewhere).

                The book goes into this pretty extensively, although it does not credit Leon Walters with the invention of this swelling resistance scheme as he has been elsewhere. He was also an upper manager of mine at one point.

                Moderation in most things.

                by billmosby on Fri Jun 29, 2012 at 03:28:09 PM PDT

                [ Parent ]

                •  Well that's good news. I have seen some "Pu... (1+ / 0-)
                  Recommended by:

                  burner" schemes with Zr alloys, but I guess it wouldn't make much sense to do that in a fast spectrum.

                  The book seems as if it would be an interesting read.

                  One of the interesting things about the higher actinides, the transplutonium actinides, is that they generally have a well defined +3 oxidation state.

                  It turns out that the associated electronics have the advantage of stabilizing the delta phase of Pu:   This is why gallium is used in nuclear weapons plutonium.    I have seen reference made to the use of Am - one would think that Cm would be even better - to stabilize phase changes.

                  One of the fun things about the fast spectrum, as I'm sure you know, is the huge shifts in fission to capture ratios, which has the fabulous advantage of high neutron efficiency.

                  There's of course, a much smaller accumulation of higher actinides as a result, something about which I'm decidedly ambivalent, because I'm rather fond of curium and californium, and even, under some circumstances, americium.

                  Should humanity survive, I think this high efficiency is going to be very, very, very, very critical (excuse the pun) to maintaining a decent life style for however many billions of people continue to exist.

                  The problem of achieving fast fissile growth could be very important in the future, and the only people I see really, really, really thinking hard about this is the Indians, mostly because of their situation with respect to uranium and thorium.

                  If they pull it off, they may be in the catbird seat in the second half of the 21st century should there be a second half.

                  •  I was on a quest to find Pu without gallium once. (1+ / 0-)
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                    In support of the experimental fuels program for the IFR, in about 1991 or so. They wanted to make a fuel alloy that would have a significant amount of Am in it so they could make U-Pu-Zr-Np-Am alloy. they did have 100 g of Np metal on hand but no gram quantities of metallic Am. We looked around the complex and finally found something that fit the bill- heels from a LLNL laser  Pu isotope separation prototype process. The Am was left behind, and we got several Kg of that stuff. They did end up chipping off a piece of one of those that had high Am content. They knew that throwing it into the melt would boil off some of it due to its high vapor pressure relative to the other metals. They hadn't bargained on a bit of some salt being in the piece and got a bit of fireworks. But the glovebox they used was up to the task. Good thing because it was about 40 feet from the Argonne-West cafeteria. It was in a wing of the building that housed the radiochemistry labs, so it was well filtered and ventilated; the cafeteria was one wing over. But still, imagine planning a facility like that today. That lab was staffed with an engineer and two (male) technicians. Later on the two techs were replaced by one female tech, lol.

                    Moderation in most things.

                    by billmosby on Fri Jun 29, 2012 at 05:56:07 PM PDT

                    [ Parent ]

                    •  Fascinating. It sounds kind of like heaven, (1+ / 0-)
                      Recommended by:

                      being able to play with macroscopic quantities of those elements.

                      I could have had a field day in that place.

                      But...sigh...something else happened.

                      Probably you've read Weinberg's "First Nuclear Era," about his reactor ideas and the stuff they built.

                      You hear people say he was all about the MSR, but when you read him, there's something quite different, true creativity and free thinking.

                      I can only imagine what his kind might have done in this world of advanced materials science.

                      It's a real pleasure to talk with you.

  •  Timing is everything: article just in on (2+ / 0-)
    Recommended by:
    NNadir, billmosby

    Extracting nuclear energy from seawater

    From one of NNadir's regular readings (I presume) "Chemistry World".

    This article has a short piece this month on this very issue!

    Go figure?


    Dr. Isaac Asimov: "The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny ...'"

    by davidwalters on Fri Jun 29, 2012 at 10:11:14 AM PDT

    •  I wouldn't say that the RSC stuff is on my... (0+ / 0-)

      ...regular reading list, although I stumble into their journals from time to time from Google Scholar.

      This is a slightly new resin.    I haven't looked at this problem for a long time, since its value is heuristic only:   There's plenty of uranium and thorium from mines and we don't need to do this, but it is interesting, and I'll follow up.


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