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View Diary: Japan's Advanced Nuclear Fuel Recycling Plant Begins Operations. (33 comments)

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  •  Japanese MOX Plant (0+ / 0-)

    Is the plant reprocessing spent fuel to MOX now?  What's the level of coolant needed?  How much low level waste and what kinds?

    Thanks for the clear and informative diary.

    Solar is civil defense. Video of my small scale solar experiments at http://solarray.blogspot.com/2006/03/solar-video.html

    by gmoke on Sat Feb 17, 2007 at 09:10:00 PM PST

    •  The plant is recycling spent fuel now. (2+ / 0-)
      Recommended by:
      kurt, Quinton

      It is almost certainly not at full capacity and is apparently in a "shake down" mode.

      I do not know the technical details for the coolant flow rates, but given that the fuel is spent the cooling is not comparable to what is in a reactor, since under those circumstances it would still be in the reactor generating steam to drive the turbines.

      This is a new plant.   It is almost certainly robotic and designed to minimize direct handling.  This would suggest that the low level waste represented by things like gloves is probably minimized.

      I am not familiar with the technical process details, but I can say this:   The "nitrate" reference in the procedure name indicates that this is wet chemistry based on nitric acid dissolution fuel.   Thus it is most likely a close analog to the "PUREX" process at La Hague with some improvements that cause plutonium to be carried with uranium.

      While I am satisfied that the plant represents a huge improvement - simply because it recovers uranium for direct reuse in the MOX - I also strongly suspect that PUREX chemistry is not the ideal processing scheme forever.   Invariably it involves solvents and extractants, both of which probably end up as some low level waste, even with solvent recycling.

      I believe that electrorefining methods and/or molten salt extractions will ultimately be preferable to wet chemistry, simply because such methods minimize the need for solvents.   However none of these methods have been commercially demonstrated.

      •  Thanks, NNadir (1+ / 0-)
        Recommended by:
        kurt

        This is interesting news, and I am sure you will keep us in the loop as the plant leaves shakedown mode.

        You hint towards the end that you think yet another process will end up being even better, that also sounds like good news.

        I have a slightly off-topic question to ask you. Did you see the Dr. Bussard Google Video concerning some new kind of confinement fusion?

        If not, I'll find the link for you. If yes, what do you think of it? If there existed a new fusion process and a clean or cleaner fission process, which would be better for the earth? Or should we pursue both?

        Thanks,

        Lefty!!!

        "There is a time for compromise, and it is called 'Later'!"

        by LeftyLimblog on Sat Feb 17, 2007 at 10:54:05 PM PST

        [ Parent ]

        •  I'm not much of a fusion guy. (1+ / 0-)
          Recommended by:
          Plan9

          Fusion has not generated a single watt of grid power.

          If it does someday, it will still depend on access to tritium.   Because the fusion reaction produces one neutron, and because of other technical considerations, I really don't see how fusion could work without a fission infrastructure to support it.

          The world supply of tritium right now is about 18 kg.  It has been accumulated over many years, decades really, as a side product from CANDU operations.  Most of it remains in Canada.  A 500 MW fusion reactor would consume, as I understand it, all of that tritium in about 6 months.

          If you produce the link, though, I'll look at it.   I haven't seen it.

      •  We need 3 of these plants in US (2+ / 0-)
        Recommended by:
        Ray Radlein, ormondotvos

        You say the Japanese MOX plant can recyle 800 MT/yr.  The 103 US reactors produce about 2,000 MT/yr of spent fuel.  So we would only need 3 Japanese-style plants to undo the annual US production of spent nuclear fuel.

        You probably have mentioned thorium fuel in one of your diaries.  There is some promising research going on in Russia in this regard.  Thorium is three times more abundant than uranium.  It does not make plutonium as a byproduct--in fact thorium can "burn up" plutonium in a reactor.  That would take care of concern about proliferation.  Also the waste is said to be much smaller in volume.

        Advocates of the thorium fuel cycle say it would be better than MOX.  What do you think?

        "Well, I'd like to hold off judgment on a thing like that, sir, until all the facts are in." --General Jack Turgidson

        by Plan9 on Sun Feb 18, 2007 at 10:46:41 AM PST

        [ Parent ]

        •  The thorium fuel cycle has a great deal to (5+ / 0-)

          recommend it.

          I will probably write about it in a future diary.

          The thorium fuel cycle was used in the very first commercial reactor to operate in the United States, the Shippingport reactor.

          It is possible to use the thorium cycle to acheive thermal breeding with CANDU type reactors.   It is also possible to incorporate this cycle to reduce plutonium inventories by much greater amounts than is possible with MOX.

          The thorium fuel cycle does require, because of a side reaction that produces U-232 resulting in certain daughters, particularly Thallium-208, that have high gamma outputs.   Thus thorium based fuels will require remote handling.   In the age of robotics this is somewhat less of a problem than in former times.

          Thorium is only more plentiful than uranium if you consider ore bodies.   It cannot be recovered from seawater and therefore may not be as large a resource as uranium.

          Ideally in my view, the important advantages of thorium fuel cycles will be further commercialized, but they will be integrated with MOX.   To fully exploit uranium it must be converted to plutonium.   This can be done safely I think, but we need to do so with careful balance of risks and benefits.

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