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  1. From a technical feasibility perspective, would Naval Reactors be able to incorporate the Pu239 as fuel for reactors? I would think NR would have to launch a program to determine the best usage and operating characteristics but I am sure that it would be cheaper than anything we are doing on the civilian side. Also, I doubt Russia would agree to it, but then again they are withdrawing from the agreement anyhow. This would allow us to sidestep the current mess while getting useful power from this material.

      1. Or pay Russia, or both.  They’ve got the facilities to do it.

        How did Japan make the MOX for Monju?  Maybe they’d be able to handle part of it.

        1. That, and Japan is not a nuclear weapons state and might have political and/or constitutional difficulties with the concept. France not so much. Russia, political: hard to see them not help us make an own goal.

          U.S. Navy might have both operational difficulties, and perhaps some entrenched resistance, to the concept of Russian nuclear experts doing on-sight verification and inspection at highly classified U.S. facilities.

          Russia might go for it, though. Thing is, since 1994 most international FNR research has migrated from Idaho to Russia. I haven’t researched it, but my guess is that Russia does their commercial FNR fuel blending and production free and in the clear.

        1. Maybe not any longer. Russia has announced its intent to pull out of the agreement while continuing its promise to permanently convert its Pu to a form that cannot be weaponized.

  2. The part about the megatons to megawatts (disposal of Russian U235) got me wondering, what if anything was done with the corresponding US weapons U235? Did any of that get used in reactor fuel?

      1. Thanks Finn. So it looks like nearly 100 tons of US military HEU has been downblended into reactor fuel. That’s a lot of MW-hrs.

  3. What his happening with the $250-350M *per year* that DOE has budgetted for this MOX project? That seems like enough they should be able to keep making progress?

    Rod just says, “which is just a bit more than the continuing overhead for the project.” What *is* the continuing overhead for the project?

  4. Kirk Sorensen recently presented “Thorium and MSR Fuel Strategies“ at the 2016 MSR Workshop at ORNL, and the slides are available. They detail the chemical processing in a LFTR, as well as a variant processes for spent fuel, allowing the TRUs to be consumed and the remaining clean uranium to be set aside. It would also be useful to consider how MOX might fuel conventional reactors while simultaneously kickstarting the more attractive thorium fuel cycle.

    The question of past economics aside, can the MFFF be repurposed to produce Pu/Th MOX fuel instead? Conventional LEU MOX may result in a distribution of isotopes useless for weapons, but it will also be unattractive for fuel. Choosing the LEU path will ultimately grow the amount of spent fuel, including plutonium and other TRUs. The “waste” from Pu/Th MOX on the other hand is almost a perfect feed for molten salt reactors, which could actually eliminate spent fuel and TRUs, rather than just pushing the problem further down the road.

    1. My understanding is that fast-spectrum reactors aren’t terribly sensitive to the Pu isotopic mix (some isotopes have slightly different cross-sections than others but the fission probability of all of them is very high), but I’m hardly an expert on these matters.

      Monju did require a fuel fix of some type after its long hiatus, but the nature of this was never specified.  My suspicion is that it was due to the (relatively rapid) decay of Pu-238 to U-234; nothing else goes fast enough to make a big difference in just a few years.

          1. Interesting link, thanks. You can infer the perfomance as fuel from fig 10 and table 1. Of the fissions that do happen, 50%,45% and 5% eequred 1, 2 and 3 neutrons. That would be 1.55 neutrons per fissio, not too bad. But accordin to table 1 calc 14, after 3 years in Superphenix with flux 4e15 only 2.15 of 12.9 kg act have fissioned. But 3.17 kg of U234 precursers have been generated, which reqire another 1.45 n per fission, plus another 0.7 n from .86 kg Cm isotope which require at least 2 n each. Overall as good as fuel as wet manure. Burns eventually but requires lots of real fuel to get going.

    2. @GreenEntopy

      Get the LFTR design certified and built first then let’s see how it performs. If there still is surplus Pu waiting to be turned into MOX, then we can see if this pathway is worthwhile over burning the surplus Pu as MOX in current LWRs. I would expect that the fuel design work and necessary testing-fuel qualification for Th-based MOX would not be an easier path than what has been done to date to use MOX in LWRs.

      Flying Finn

  5. Re: “Aside: I’m convinced that fear of the plutonium economy was created and stoked by people who really liked the way the hydrocarbon economy was working for them. End Aside.”

    I think while that may be in part accurate, it’s my experience that the majority of people have genuine Hollywood and pop-culture stroked fears about plutonium quite apart from any affection or thought for fossil fuels. Here at NYC’s esteemed Hall of Science in Queens, plutonium is only mentioned as bomb making material with a small (regrettably) redeeming aside that it keeps Mars Rovers rolling. Not one TV or movie as been made for decades that mentions plutonium in a positive light. (Does anyone bristle at that scene in the original “The Thing” film where the scientist is telling the soldiers and reporter of the gifts science has brought mankind like splitting the atom and the reporter snickers; ‘Yea, that was a big help!”) So saying, I don’t have to mention how the media regards plutonium. Again, winning hearts and favors for nuclear energy is front-most and ever an advertisement war.

    James Greenidge
    Queens, NY

    1. @James Greenidge

      Who do you think paid for the “Hollywood and pop culture stoked fears about plutonium?”

      Have you ever read Upton Sinclair’s “Oil?” Do you know how influential oil and gas sponsorship was in developing Hollywood and creating propaganda and mythology? Do you know how influential the coal, oil and gas industry were in establishing US foreign policy and how tightly they are tied into the MIC that Eisenhower warned about?

      1. A shame that. As you well know, during Walt Disney’s hey day, nuclear energy was getting some pretty positive press.

        When we discuss media induced ignorance about nuclear energy and radiation, we tend to think that we are referring to John Q. And truly, when the discussions here turn technical, this John Q doesn’t wade in too deep before he’s hopelessly lost. So, it doesn’t take much FUD to fill such a brain with ignorance and false info, planted nurtured to serve an agenda. And energy policies aren’t the only politically driven agenda of the day that is well served by carefully cultivated widespread ignorance. Watching the electoral cycle run its course, I am stricken by the blatant demonstration of ignorance that is exhibited by the candidates themselves, never mind John Q. They, (God help us), one or the other, will determine policy. What makes them more capable of understanding science, at the depth that policy should be decided on, than I am? Point being, they are probably as ignorant of the science behind safe NE as John Q is. So, enter lobbyists with an agenda, buying advisors with an agenda, advising a President and his cabinet with an agenda….and zoom, down the tubes we go. For quite sime time now, on here, I have lamented, strongly, how screwed up, and despicably corrupt, Washington is. If you’re watching this clown show campaign season, and you disagree, you ain’t paying attention. And you think either one of these Bozos will base energy policy on fact and sound science? Dream on.

        1. Our choice in November isn’t as binary as the media and political establishment would like you to think.

          Gary Johnson and Bill Weld are legitimate, experienced politicians and problem solvers. They were both two term governors who were officially members of the Republican Party in states with Democratic Party in the majority of voters.

          Don’t let people tell you that America has a two party system and that any vote cast for a third or forth party candidate is wasted.

          1. Don’t let people tell you that America has a two party system……

            If you don’t think it is an ENFORCED two party system, Rod, I don’t know how you can draw that hold that view. The blatant and purposeful exclusion of third party candidates from participating in the presidential electoral race is glaring evidence contrary to your statement.

            And if you are talking about a strong vibrant democracy led by moral and laudable leaders, ANY vote this time around is a wasted vote. No matter how this embarrassing spectacle ends, we lose.

  6. Rod, MOX has consistently demonstrated little to no value either in (1) getting rid of used nuclear fuel (it only recycles 1% of a fuel bundle) or (2) offsetting the cost of uranium fuel used in reactors. MOX just displaces fuel in an existing reactor with a more expensive fuel. What’s the point?

    Integral fast reactors, however, can recycle plutonium and do exactly as you suggest in your article – provide up to a 1,000 years of fuel-reliable energy. Additionally, they can get rid of long-lived actinides at the same time. All while generating additional clean energy.

    1. The MFFF has nothing to do with recycling Pu from commercial fuel assemblies.

      I wouldn’t have chosen it as the best way to use 34 tons of material taken from the weapons stockpile, but given the fact that the decision was made and funded to the point of a 70% complete construction project, I’d rather complete the facility than start all over.

  7. Rod, a minor comment and a more general one.

    Minor comment: Nothing heavier than Li-7 was made in the big bang. All elements heavier than iron and nickel, including neutron-rich thorium, uranium, and plutonium, were made in supernovae explosions that involved the production of neutron stars. However, all of the isotopes of plutonium have significantly shorter half-lives than the age of the solar system, 4.5 billion years, so all of the plutonium used on Earth are made in nuclear reactors. The plutonium that powers radioisotope thermoelectric generators, Pu-238, used in the space program is not a fissile form of plutonium, as is the weapons-grade Pu-239.

    More general comment: Although I am not an expert of fuel fabrication for reactors that use solid fuel elements, my impression is that MOX fabrication starting with commercial fuel assemblies is difficult and expensive because the composition of Pu/actinides from available sources is different depending on the reactor involved and the length of time that the spent fuel has been in storage. As a consequence, getting uniformity of the fuel pellets is difficult. Inhomogenieties can result in “hot spots” that compromise one or more fuel pellets and result in the release of fission products during a burning cycle.

    The difficulty should be less with fabrication of fuel from weapons-grade plutonium with a certified pedigree, as you imply in your reply to huntster. But the most suitable reactor for getting rid of all forms of unwanted plutonium/actinides is a molten-salt reactor (MSR) where the nuclear fuel iis dissolved in a liquid fluoride salt automatically made homogeneous through turbulent mixing by pumping it through pipes at a sufficiently high speed. Moreover, a fast neutron-spectrum is not needed if the MSR is a breeder that produces U-233 from Th-232 because the excess neutrons released by fissioning U-233 can be used to destroy the Pu/actinides completely simply by recirculating these species through the reactor core until they are all gone. In the case of destroying weapons-grade plutonium, because of the limited solubility of PuF3 in liquid fluoride salts, it is best just to fluorinate the Pu-239 directly, thereby saving the expense of down-blending the plutonium.

    1. @FShu

      Re: your minor comment:

      I’ve revised the post to reflect your correction. Would you do me the honor of checking to see if my current phrasing is accurate enough?

  8. I remind all that the British nuclear regulatory agency is reviewing the GE-Hitachi PRISM for use in eliminating their excess weapons plutonium stocks. The plan is to denature the plutonium in about 6 years and use the result to generate electricity for about 60 years.

    The review is scheduled to be completed in December. If positive, the USA could proceed to do the same. I suspect that the cost would be far less, far, far less than completing the PUREX/MOX facility.

    There is an interesting paper from Georgia Tech describing connecting a PRISM to a thermal store. The turbine/generator is only connected to the thermal store, providing load following. More important, according to the article, such an arrangement is not subject to NRC oversight.

    1. @David E. Benson

      There is an interesting paper from Georgia Tech

      Specifically, the paper author is Cal Abel, an old friend and contributor to Atomic Insights and the Atomic Show.

        1. Unfortunately their study failed to recognize that BPA, is public power financed at sub 3% long term bond rates reducing the calculated power costs to the under 4 cents a kwh range provided all in by the public power Energy Northwest reactor at Tricities.

          Why studies always use the notoriously inefficient American private power is beyond me.

          1. I’m not sure I follow. As I read it, Abel and Petrovic only used BPA for their wind and reliable generation profile, so they might spec their load following requirements for use where wind has grid priority.

            IIRC NuScale uses BPA generation data the same way. No, it doesn’t make economic sense to pay for the same electricity twice, but that’s the subsidy framework we’ve elected, and reliable generators have to deal with it.

  9. As FShu points out, all the actinides were produced in supernovae and not the big bang. Which is good otherwise the fissile content of Uranium would be about 1000 times lower and the plutonium economy could never have started. I fully agree on your assessment of the political reasons for the demonisation of the plutonium economy.

  10. @Rod Adams,

    “The second track was a Mixed Oxide (MOX) fuel fabrication facility modeled after the long-established French system.”

    which was based on the longer-established US system.

    Meanwhile in the real world, quality issues in the French nuclear system are causing higher prices, and more coal and gas burning:


    “Though its first use was in explosives,… Plutonium’s real attraction to specialists is the fact that it can be readily produced from U-238, which is a mostly useless isotope that represents 99.3% of naturally occurring uranium.”

    “Even without breeding, plutonium is a useful fuel source; 25-40% of the energy produced during the reactor residence time of conventional nuclear fuel comes from plutonium fission. ”

    So, really, U-238 is NOT mostly useless, even in conventional, once-through power plants. Fast fission makes it even more directly useful, in both power plants and in explosives.

    “it has been difficult for the MFFF contractors to attract and retain the talented management and inspired workers needed to complete a challenging, one-of-a-kind project in a relatively remote part of the country.”

    Funding uncertainty, sure. Remote location, not really. Most nuclear projects have been in “relatively remote” parts of the country. Calling central/eastern SC “relatively remote” sounds particularly funny, however, coming from someone in central VA.

    “but given the fact that the decision was made and funded to the point of a 70% complete construction project, I’d rather complete the facility than start all over.”

    It would be interesting to see lists of abandoned federal or nuclear projects versus (estimated) percent complete. Cutting your losses is another relevant concept, along with the adage that the last 10% takes 90% of the effort/cost.

    “The MFFF has nothing to do with recycling Pu from commercial fuel assemblies.”

    Other than the part where you demonstrate processing Pu and making commercial MOX fuel with it.

    That’s like saying Shine Medical Technology’s accelerator-driven, subcritical liquid reactor has nothing to do with liquid reactors. If it works, a good demo of similar technology never hurts.

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