16 Comments

  1. I have lost count of the number of times people have asked me ‘what do you do with the waste?’ However i find amusement in their response when i try to explain vitrification, spent fuel reprocessing, isotope seperation and breeder reactors. The response is usually one of surprise. Another method being put forward for disposal of high level waste is entombment in copper blocks. This could prove as effective as glass as a barrier. More interesting is the question of low level waste. Plans in all countries call for storage, however i wonder if recycling might be the better path.

  2. Looking forward to it Rod, NNadir always has well researched and though-provoking posts.

    The nuclear waste problem, consists of three parts.

    Nuclear. The word is considered evil, but few understand that anything with nuclear is high energy density, therefore very small. The spent fuel rods of a large plant operating for 60 years fit in dry casks occupying a medium size parking lot.

    Waste. It’s not really waste, almost all the isotopes are valuable. Valuable noble gasses, noble metals, valuable medical isotopes. All in there. We know how to get these out and seperate them – it is being done widely in the medical reactor community, but somehow is not allowed for power reactors.

    Problem. What problem, dry casks work very well. They are passively safe. Just a bunch of concrete packs with stainless steel drums in them. The drums get hot from the decay heat of the fuel rods stored in them. Openings at the bottom and top of the concrete pack allow air in but block the radiation. This cools it. There are no moving parts. There is nothing that could happen to them that will cause a large release of radioactive particles. They have never harmed anyone. Fukushima had dry casks. One of the things that worked very well, as all the casks were fine, despite a serious earthquake and tsunami. Pretty convincing fire test.

    If you put the spent fuel in casks it becomes less and less radioactive over time. All you have to do is wait, and the problem becomes smaller every year. Few toxic wastes have such excellent self-cleanup properties. Mercury from coal doesn’t clean itself up in a trillion years. The casks are zero maintenance.

    I’d like to point out the book of Cohen again, which has two chapters on waste that are highly scientific, educative, convincing, and eye-opening.

    http://www.phyast.pitt.edu/~blc/book/chapter11.html

    http://www.phyast.pitt.edu/~blc/book/chapter12.html

  3. @ Rod,

    …. Before you do, pull out your periodic table;

    Now the anti nukes are going to bring Chuck Norris into this as the only valid element is the element of surprise …

    Be careful as to the choice of weaponry you bring to the table !

  4. Some antinukes would contend that the volumes of tailings produced at uranium mines makes nuclear as bad as coal from the standpoint of waste. As far as i can tell the tailings canbe managed and could even be placed in the mines from which they were dug

    1. @Josh

      You are correct. The plan for Virginia Uranium is exactly that – put as much of the tailings as possible back into the same hole they came from. Of course, during mine operation, there will be a large quantity of material that cannot be in the hole that is being worked; the solution there is to dig another nearby hole, line it with several layers of impermeable material, and put the tailings in that hole.

      It still boggles my mind that there are supposedly educated people who are worried about living “downstream” of such a facility when they have no problem living “downstream” of any human population center. Every settlement of any size generates sewage and trash that is far more mobile and environmentally risky than uranium oxides. That material is not very water soluble and carries little or no risk even if present at the maximum quantities that can possibly be carried in either water flow or the wind.

      I was intrigued, amused and encouraged by this article on SmartPlanet:

      http://www.smartplanet.com/blog/bulletin/the-secret-to-longevity-wine-and-radioactivity/9560

      Credit to JimHopf, who posted the link in a comment in another thread.

  5. Abandoned uranium mines and tailings heaps seem to have been a problem in the southwest of the US, although it seems these mines were used to service the weapons programs (from the 1940s through to early 1980s) rather than civilian nuclear power. The problems with tailings (daughter products etc) appear not to be an issue where mining is carried out to a high standard.

  6. I love hearing from NNadir on this topic, as my undergrad degree (a few millennia ago), and my introduction to nuclear technology, was Chemistry.

    I knew that he (and Steve Skutnik) would be able to appreciate, and take to new levels of ingenuity, the unique and elegant NF3 reprocessing option.

    Kirk Sorensen also has a YouTube video on this topic as one of his Google Tech Talks.

    I may have missed it, but I didn’t hear a lot of talk about the recovery of valuable chemical, let alone energy, resources being discussed during the Blue Ribbon Commission hearings. That’s a pity, because our current NRC Chair, as a member of that committee, might have been awakened to the possibilities of a national state-of-the-art reprocessing center as an adjunct or replacement for Yucca Mountain. There is certainly plenty of money lying fallow to accomplish that, and the value of the “spent” fuel, if properly utilized, would yield a hundred-fold return on investment for the American taxpayers.

    Sometimes I think our only way out of the political mire on the nuclear “waste” issue will be when some visionary CEO takes the reins of a powerful company like Exxon/Mobil, realizes that they are in the “energy”, not “fossil fuel” business, agrees to take all the spent fuel off the government’s hands for a pittance, builds their own modern recycling center (offshore, if need be), and then proceeds to make a fortune extracting and reselling the valuable components contained therein. Of course realistically, there would be massive “environmentalist” and non-proliferationist opposition for taking the initiative in doing something that our government should have been doing, and perfecting, over the last four decades. That, and the fact that the heads of most large corporations, unless they are the founders, don’t get there because they are visionaries.

  7. Well that was fun, despite the fact that during the conversation, I made some technical errors. For reasons that escape me, I kept referring to well known hexafluorides as tetrafluorides.

    The tetrafluorides of plutonium, neptunium, and uranium are not volatile, and the exploitation of their variable oxidation states is critical to their separations via fluoride volatility and similar procedures.

    I should probably slow down my mouth a little bit, and maybe speak up.

    Thanks Rod, for the chance to talk.

  8. Looking forward to a wide podcast roundtable on Nuclear Energy and the Media and how nuclear advocates can break out of blogs and be heard as consultants and in special features or PSAs in the mass media, as well as the emotional tactics and FUD slung by anti personalities and pop culture media “science consultants.” Included might be how “high brow” nuclear engineers can talk “grass roots” with the public on nuclear issues, as exampled by green converts to nuclear energy, and why don’t more pollution aware public health authorities speak out more for nuclear energy. Discuss the non-PC issue of a biased “balanced” media aligning themselves with anti-nuclear groups vis-a-vis SONGS and Indian Point and Diablo Canyon.

    James Greenidge
    Queens NY

  9. 1) Somewhere along the way, NNadir mentioned that ‘radioactivity’ was used to clean water and the air.

    There was not enough details as to how this was achieved and what isotopes were used (Rod mentioned Cs but that was not confirmed) and how far we are in the process. This could be big if it was shared with the public.

    2) Also on the medical side of things, Cs is no longer used in Canada but has been replaced by Iridium 92. I was told it was because of the length of the half life (73 days only for Ir 92) and the perceived ease of management (30 year half life for Cs)

    3) NNadir also pointed out that Tc used for medical purposes was now being made from colliders (or something like that – It was a argument used by the ani nukes when closing Gentilly II in Québec that nuclear wastes were no longer needed for medical purposes)

    My point, on the medical side of things, is that Monbiot often states that without the wastes, there would be no nuclear medecine. What exactly is left to the specialized nuclear reactors in terms of valuable medical isotopes if Cs is being phased out and Tc is produced by other means?

    1. Cs-137 decays to Ba-137m, which emits a 662 keV gamma ray.  The energy of the beta particle is quite small by comparison.  I’m assuming that these gammas rid water of pathogens by means of Compton-scattered electrons generating free radicals and destroying biological materials.

      1. @Engineer-Poet

        That’s correct. Since Ba-137m has a half-life of just 2.5 minutes, it is a good enough approximation to say that Cs-137 is both a beta and gamma emitter. I have a strong enough interest in irradiation as a means of sterilizing medical instruments and reducing food pathogens that I visited a company in Polk County, FL that used to have the name “Vindicator”. They are one of the few companies in the country that are licensed to irradiate both instruments and food. (I think they are now known as Food Technology Services.)

        At any rate, they had some materials that described how they had evaluated Cs-137 as a potential replacement for the Co-60 that they normally used but were having some difficulty obtaining at a reasonable price. There are several such devices in operation around the world.

        http://www.epa.gov/rpdweb00/sources/food_irrad.html

        Believe it or not, there were some local protesters who campaigned against the idea of even considering reusing “nuclear waste” for such a purpose.

        I suspect they probably received some funding from people who were more interested in manufacturing machinery to artificially generate weaker rays using vast quantities of energy rather than allowing anyone to take the low cost (low revenue for machinery makers) path of using the natural decay properties of a material that some prefer to use as a trump card against the use of nuclear energy.

        (Yes, I really am pretty cynical when it comes to man’s inhumanity to man when greed is involved.)

        1. I love it when study of physics pays off with understanding of something never investigated before.

          I suspect they probably received some funding from people who were more interested in manufacturing machinery to artificially generate weaker rays using vast quantities of energy rather than allowing anyone to take the low cost (low revenue for machinery makers) path of using the natural decay properties of a material that some prefer to use as a trump card against the use of nuclear energy.

          Not only does the artificial radiation require energy input, the device has numerous failure modes including simple loss of power.  If it fails, it allows un-treated material through.  The need for maintenance limits applications in e.g. remote areas.

          Steve Aplin and I talked about this a bit.

  10. Great show Rod, enjoyed it very much and learned a lot. Two comments:

    1.) Perhaps as a topic for a future show one could talk in detail about the differences in fission products from different fissile materials. For example, among the fission products of U-233 and Pu-239, are there additional valuable isotopes that are not found among the products from the U-235 reaction ? And should that be a consideration, as societies decide which reactor types to pursue? Kirk Sorensen has touched on this subject in some of his talks and would be a qualified guest. He mentioned for example the possibility of cancer treatment with Bi-213 derived from the thorium cycle.

    2.) Broader uses of irradiation (excl. food irradiation here). The topic of wastewater treatment came up in the talk. Intrigued, I looked up some further uses of irradiation that had been proposed in the past. One such area is the treatment of “sick soil”, where certain pathogens have colonized the soil and are having harmful effcts on crops and livestock. Today, this is often remedied with steam sterilization. It gets rid of most of these pathogens, although some spores may survive the heat. The soil can then be recolonized with a more beneficial microbiome. The emerging “superweeds” could also be removed by soil irradiation. I only found a handful of papers from the early 1960s that dealt with irradiation as a means of soil sterilization (googled “soil irradiation”). But other than that, this method never seems to have caught on. Steam is energetically expensive, so it would be good to have irradiation as an alternative. In most cases, steam is probably made with natural gas. I can see additional uses of irradiation in agriculture, wherever microbes are involved (e.g. sterilization of manure, irradiation of feedstock for biogas digester, preparation of feedstock for silage), any kind of emerging synthetic biology that uses agricultural feestock. Agriculture is an even more powerful global industry than fossil fuels, so they could make this happen if they wanted to.

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