Leave a Reply

Your email address will not be published. Required fields are marked *

Subscribe to Comments:


  1. Fission products include platinum-group metals.

    These are extremely valuable as catalysts.  Some are radioactive and would not be suitable for e.g. catalytic converters in vehicles, but in an industrial chemical process which is already enclosed in a heavy steel vessel, would there be any real obstacle to putting them to work?

    Perhaps we’d have to fix radiation exposure standards and define a tolerance dose as “below regulatory concern” first.

  2. Correct me if I’m wrong but wasn’t the IFR made to burn up the waste to a manageable human level in terms of a hundreds years VS thousands? At least according to Roger Blomquist. Just finishing the HBO special Chernobyl, so much disinformation it’s laughable. Hopefully someone makes a real movie/documentary on this. Pandora’s Promise was a documentary that convinced me that Nuclear is the future!

  3. Rod – thanks for this post and the discussion of the it-seemed-like-a-good-idea-at-the-time decision to have spent fuel be the property of the government, before there was any real thought given to what to do with it.

    Dan – there are several new reactor designs capable of re-using spent fuel and getting more value out of it, but I don’t think anyone in the USA is working on the problem of making recycling of spent fuel routine. That would amount to the heresy of ‘reprocessing’. In Canada our Canadian Nuclear Safety Cmmission might be more approachable. The IFR certainly was and is something that will help, but once again probably didn’t include an effort to allow reuse of used fuel.

    Kirk Sorensen, with Flibe Energy, is making extraction of fission products part of his business plan, as far as I can see. He has greater ambitions as well. The video
    Thorium Debate / Molten Salt Reactor Forum @ ThEC2018 ( https://youtu.be/2x7do-_MTD0 ) is worth watching. Kirk mentions (at 10:18) that he wants to produce ‘medical radioisotopes that can’t be made any other way (than in a thorium/U233 reactor)’

    1. @Andrew Jaremko:

      IFR, as embodied in it’s EBR-II prototype, included a highly successful effort to re-use it’s own used fuel, with the idea the technique could be used for used LWR fuel as well:
      Plentiful Energy: the story of the integral fast reactor (Charles Till and Yoon Chang, pdf) is a fascinating read, with some truly Out There chemical engineering.

      If used to fuel such reactors, our current US inventory of used LWR fuel could power the entire country, at current electricity consumption, for 70 years — no additional mining required.

      Add in our stockpile of DU left over from enrichment, and we could stretch that out to nearly 900. With that kind of U238 burn-up, the estimated $300/kg UO2 cost for seawater extraction becomes close enough to trivial not to matter.

      I’ve nothing at all against Molten Salt Reactors as another way to push the envelope, and wish FLiBe, Terrestrial, Thorcon, Moltex and friends every success. But I do so keeping firmly in mind that the safe proliferation-resistant fuel reprocessing problem is one that has been solved.

  4. Couple of thoughts:

    The Bulletin of Atomic Scientists only exists to scare people. Every year they put up their useless “Doomsday Clock” to scare everyone into thinking we’re all going to die in an apocalypse, and every year the press dutifully reports on it. This is basically another clickbait article.

    I’m fairly convinced the United States congress has no interest at all in resolving any issue it is tasked with solving. I also believe this is a feature built into the system, not just a recent phenomenon. If they were to accidentally fix something once and for all, they’ll need to find something else to campaign on. By only messing around with the gingerbread they can continue “the good fight” for their voters (but not their constituents).

  5. I’ve been certain for some time that reprocessing LWR fuel for reuse in LWR (as the French do) is not better than enriching new LWR fuel. This is because the SNF has less Pu than natural uranium has 235U, thus ~8 SNF assemblies must be reprocessed to make a single new MOX assembly with 4.5% fissile content. Reprocessing LWR SNF into MOX amounts to breaking up small, durable, easily-stored, waste packages (the spent fuel assemblies) into multiple diluted waste streams that must then be re-concentrated and re-packaged for storage. Reprocessing LWR SNF is aligned with the national interests of France, a country that apparently fears interruption of their nuclear fuel supply and thus values MOX manufacturing as an insurance policy – sort of like doomsday prepper food in the basement.

    I was very comfortable with this reasoning until I began to do some light reading about the last experiment performed at the Shippingport Atomic Power Station: https://www.nrc.gov/docs/ML0923/ML092310709.pdf

    Rod has written plenty about Shippingport over the years, but several concepts ‘clicked’ together for me upon learning some of the specific details of this Th-U MOX core, which was designed by HG Rickover’s crew in the late ‘70s. Now, I’ve come to the conclusion that this technology was abandoned because it worked too well and presented a proliferation risk – a genie in a bottle.

    1. Remarkably: The average fissile content of the core was 2% if you neglect, and 1% if you include, the 18.5 ton ThO2 blanket (radial reflector). The maximum fissile content in any pellet was 5.2%.
    2. Interestingly: The fissile material was 98.5% 233U; it was reprocessed from apparently well-burned ThO2 loaded in Indian Point 1.
    3. Most Importantly: Thorium lacks the hexavalent state that allows Uranium to become gaseous at low temperature/pressure as UF6.

    It seems that separating the nearly 100% fissile uranium vector from Thorium MOX involves processes related to normal fluoride “conversion”, which is used to make kilotons of UF6 to feed enrichment facilities. Once the Thorium MOX is “converted”, the Uranium vector will waft out of the mixture, if provided a F2 atmosphere. This uranium contains the strong gamma emitter 232U, which is admittedly difficult for biological lifeforms to handle, but it is not proliferation resistant, per se (it can be managed).

    1. Although the US did use U233 in a test weapon, I’ve heard it wasn’t considered a success, and no other country has gone that route, suggesting it’s not so easy. Your fellow New Jerseyan, chemist and blogger Nnadir, proposes using fuel with mixed isotopes of thorium, uranium, plutonium, neptunium and curium, which would eventually allow fuel reprocessing with no need for further enrichment, and no possibility of diversion to bombs. ‘How would the fuel emerge? It would actually contain on removal 8 actinide elements, protactinium (formed from thorium) two isotopes 231 and 233, thorium that was more radioactive than natural thorium since it would have isotopes 228, 229, 230 — three that favor the formation of additional 232U in additional recycles of the same thorium — as well as the natural occurring thorium isotope, 232Th, uranium with six isotopes, 232, 233, 234, 235, 236, and 238, neptunium, plutonium with six isotopes, 238, 239, 240, 241, 242 and even traces of 244, americium with three isotopes, 241, 242m, 243, and curium with three or more isotopes, including the very hot isotope 242.’

      1. There is little doubt in my mind that “reactor grade” U bred from Th is satisfactory for simplest WMD, since 233U has low spontaneous fission rate. From what I gather, “proliferation resistance” of Th fuel cycle is attributed to buildup of 232U via 233U+n -> 232U + 2n, which yields 232U (strong gamma source) making the material difficult to handle. The fissile charge of the Shippingport Thorium MOX had a composition (vector) of 98.5% 233U, 1.3% 232U and trace 235U, 236U and 238U per page 34 of: https://www.nrc.gov/docs/ML0923/ML092310709.pdf

        This uranium was taken out of ThO2 or ThO2 MOX pins irradiated at Indian Point 1. My guess is the ThO2 was loaded in Indian Point fuel as either “driven” assemblies or HEUO2/ThO2 MOX assemblies with a ~2% HEUO2 content. The Shippingport uranium vector contains only trace amounts of 235U and 238U in a relative abundance suggesting +20% enrichment.

        From this, I distill that ThO2 can be irradiated in standard PWR yielding 99% 233U that is easy to separate-out due to lack of hexavalent state for Th. The 232U content will increase with irradiation, which will complicate manufacturing, since it is a strong gamma source. The gammas might age high explosives quickly and be a poor choice for weapons, but low spontaneous fission rate suggests suitability in “Little Boy”.

        I am offering additional explanation why our government is “not interested” in Th. The explanation is nonproliferation, in addition to economic factors and sway of special interests. U from highly irradiated ThO2 has a low spontaneous neutron emission rate, unlike reactor grade Pu. The reactor grade 233U appears to remain physically (if not practically) suitable for WMD whereas reportedly, reactor grade Pu is not. Nevertheless, both are suitable sources for WMD if the fuel isn’t irradiated long, YET it is easier to separate the fissile species from ThO2/UO2 MOX because Th lacks the hexavalent state.

        ThO2 MOX would make a great fuel cycle for power reactors. Our politicians find it to be a liability.

        1. There are many in non-proliferation world who seem willing to sacrifice useful, economic nuclear energy to prevent the mere possibility that additional nations will gain access to material that could, with some determination, be used to produce nuclear weapons.

          Given existing roster of nations that own nuclear weapons today, I cannot see how non proliferation makes us any safer than we are. It just makes us collectively poorer.

      2. Turns out I am slightly wrong and that it is the decay products of the 69-year half-life 232U which make the material difficult to handle. If we are to believe the following reference, then what I wrote about weaponizing reactor grade 233U is consistent with the conclusion made on page 23. Other parts of the document discuss ThO2/UO2 mixtures in PWR consistent with what I backed-out of the table in the Shippingport reference (i.e. 20% enriched in 235U).



        Agreed, the non-proliferation camp makes humanity “collectively poorer”.
        Nuclear energy could make the future quite bright for the other 90% of humanity.

      3. “Given existing roster of nations that own nuclear weapons today, I cannot see how non proliferation makes us any safer than we are. It just makes us collectively poorer.”

        Given how we trade with and even provide aid to nations with nuclear weapons that did not sign the NPT (Israel, India, Pakistan) and destroyed nations that gave up their nuclear programs (Iraq, Libya), the NPT is a joke.

  6. Correct me if I’m wrong, but has CANDU Energy not developed an AFCR (Advanced Fuel CANDU Reactor) that can be fuelled by reusing recycled uranium? They claim the one AFCR can be fuelled by reusing (reprocessing) the spent fuel from four LWRs. Surely this type of technology could lessen the impact of spent fuel?

    1. I’ve known that DUPIC (Direct Use of PWR fuel In CANDU) has been discussed for quite some time, but with uranium prices so low it may not make sense.

      I suppose it might work if a reactor was designed to take PWR fuel without repackaging, but I’d be concerned about cladding failures.

      1. Of course spent LWR fuel would have to be fully remanufactured to the CANDU spec, so this is clearly not viable. The CANDU fuel assembly is 50 cm long; the 30 or so rods of the bundle have whatever specific diameter, welded/brazed spacing tabs, etc.. It’s like saying you could use Honda civic crankshafts in Chevrolet, which is only possible if you melt them down and fabricate the GM part to spec.

    2. I’m in the middle of watching this hour-long talk by Steve Piet from 2015:

      Why aren’t we recycling used nuclear fuel?

      One of the things he touches on is the low TU content of used CANDU fuel, making it less desirable to recycle.  I have to note that this would probably not be true of DUPIC fuel at discharge.

      1. Elysium industries.com has greatly simplified and reduced the cost of recycling both existing SNF (to 1 chemical step), and recycling it’s own fuel (to 2 chemical steps) far simpler than the 7 steps of pyro-processing for IFR recycling only and PUREX for new fuel from SNF. Plus we eliminate the need to manufacture tight tolerances solid fuels. The elimination of mfg solid fuels means the recycling does not need to purified enough to be low radioactivity. We just use a version of chloride salt used for pyro-processing, w/o the Lithium, as the fuel, so physical transitions of state are not required. This and the simplicity allows remote automated conversion of SNF, or purification of our fuel without pyro-processing, typically morning separating Plutonium.

    3. Yes, CANDU has very little Pu content because it knocks only converts U238 to Put for about a year, vs 4.5-6 years for LWR fuels, and similar to LWRs, the CANDU also burns the Pu after as it starts to build up.

      This is what confounds me on why Moltex, which intends to operate on TRUs, in the intermediate neutron spectrum wants to build their prototype in Canada. Maybe ND boggling that you would reprocess 174 tonnes of CANDU fuel for each 1 tonne of MOLTEX fuel. Economics seem horrid. Even the DUPIC was using LWR fuel and was only 4 tonnes per tonne of DUPIC CANDU fuel. LWR → MOX is only about 8 tonnes of SNF per 1 tonne of MOX.

      1. This is what confounds me on why Moltex, which intends to operate on TRUs, in the intermediate neutron spectrum wants to build their prototype in Canada.

        Because reprocessing of UNF is prohibited in the USA.  The regulatory regime is also a great deal friendlier, per the talk going around.

        1. I’m looking forward to hearing a talk from Caroline Cochran, the COO of Oklo, early next week. She will be explaining why her company has chosen to go through the US NRC licensing process instead of seeking a way to avoid it. Part of their strategy has involved several years worth of pre-application engagement in an effort to explain their design to key NRC decision makers and to participate in the ongoing process of modernization at the NRC.

          There is extremely competent management in the agency and the current commission has some stellar leaders with wide ranging expertise.

      2. Egineer-Poet, not sure where you get your info.

        Canada neither enriched, nor reprocesses fuel.

        Reprocessing IS allowed in the US, since Reagan reversed Carter’s ban the very next term. And reprocessing is ongoing at both Savannah River National Lab, to recover international research and testing reactor fuel and is being made into conventional reactor LALEU fuel for Watts Barr to make Tritium for weapons. And Idaho National Lab is reprocessing to recover IFR and Navy Stored Nuclear Fuel. The IFR fuel is being dedicated to military micro-reactors using TRISO fuel. The Navy SNF will be used for US commercial advanced reactors and for future Navy aircraft carrier refueling with HALEU fuel.

  7. The US has ~78,000 times of SNF and about 800,000 tones of depleted Uranium from commercial and military U enrichment.

    That is 100,000,000 MWe-years, 100 TWe- years from just the US SNF (Stored Nuclear Fuel), and 1 PWe-years of power from the depleted uranium.

  8. Also, Engineer-Poet

    The talk is that the CNSC is friendlier, but the CNSC claiming a minimum licensing period of 11 years, vs the NRC Claiming a minimum licensing period proves that factually wrong. The US is trying to license non-LWRs. There are several in the process. Note that neither regulator has any experience outside of water reactors.

  9. How many automobiles could “Acme Motors” sell if in actuality they were only “Leased” and the contract required that you could not release, rent or sell the vehicle when you wanted a new one. Further you had to pay for and build a facility to store and protect the vehicle, subject to inspection at any time, which “Acme Motors” owns in perpetuity. [The on-site mess is because the NRC is not doing it’s job.]

    This also makes me think that I would sell the entire on-site spent fuel storage mess to some fly-by-night company without concern that it was probably going to declare bankruptcy and let the FEDS solve the problem.

    The Nuclear Waste Policy Act needs to be re-written.

  10. Aside as Rod says:


    Looks like they are getting the new Vogtle units built despite the baloney sausage from people like those whom wrote the article that rankled Rod.

    Recycling spent fuel looks like a good idea. However, I would think all the pro nuclear folks have bigger concerns. The country is going left. They want revisions to health care, less war and a concern about global warming. They are emulating old FDR and putting forth a “green new deal.” I rarely, if ever, hear the phrase nuclear power discussed by these well meaning folks except when they are talking about shutting down existing units. Will the potential panacea for many of the world’s present and future ills be put back in it’s bottle?

    The study of history and culture show us that a people can be “held back” by those without open minds. Will this happen to Western Culture?

      1. Something I just learned is that the VTR is a down-scaled version of the PRISM reactor, at about 300 MW(th).

        If the VTR is an enabler for PRISM, it’s probably worth the money.

  11. Rod,

    For me, the most salient paragraph in your entire post consists of: “It’s the government’s job to provide oversight. It should establish and enforce rules that provide a reasonable assurance of adequate protection, but it should allow multiple entities the freedom to devise useful parts of a functional enterprise.”
    This profound statement lies at the heart of pretty much every failure of a government attempt to become directly involved in an economy (Solyndra comes to mind) It is expressly a conflict of interest for governments to become directly involved in the economy. The function of government is to set the rules; full stop. Direct government involvement in the economy is entirely analogous to the referee in a hockey game (I apologize for being Canadian) playing a shift once in a while for one of the teams. Objectivity in the execution of that referee”s duties would be compromised.
    On the related topic of nuclear safety, Stalin managed to kill about fifty million of his own people without any nukes at all.

  12. You need to have a podcast discussion with Dr. Lauren Jackson about everything you discussed here in this article. I am very interested in the HI-STORE CISF interim NUCLEAR FUEL storage solution in New Mexico and the Orano/WCS CIS interim NUCLEAR FUEL storage solution in West Texas.

    Radiation exposure is the #1 emotional opposition to both of these sites. Nuclear fuel storage is safe, period.

Recent Comments from our Readers

  1. Avatar
  2. Avatar
  3. Avatar
  4. Avatar
  5. Avatar

Similar Posts