Energy Independence, the fast breeder solution

Background References

Data on existing commercial reactors:
From the US Energy Information Administration

Generators with a total of just over 100 gigawatts of nameplate capacity produced a total of over 90.5 gigawatt-years of energy in the year 2009. That's about 20% of the total electrical energy consumed. EIA:Nuclear Reactor, State, Type, Net Capacity, Generation, and Capacity Factor

The Thermal Breeeder Reactor Solution

This option may be even better than breeding fissile 239Pu from 238U by neutron bombardment. It breeds fissile 233U from 232Th, i.e. natural Thorium, which is about three times as plentiful as natural uranium. It seems to have been abandoned, during the Nixon administration, by the US Atomic Energy Authority, because it was not a good source of nuclear weapons material. Liquid Fluoride Thorium Reactor

The Fast Breeder Reactor Solution

A breeder reactor creates fissile isotopes from non-fissile ones. Its fuel is therefore renewable. Fissile isotopes are effective, but very scarce compared with the non-fissile ones -- by a factor of more than a hundred. The resource in fact becomes highly sustainable.

A project funded by the US Government, the Integral Fast Reactor, demonstrated in 1986 that it could be done with greater safety than any existing commercial reactor.
In an act of unconscionable ignorance, the project was closed down in 1994, on the ill-founded belief that it could lead to nuclear proliferation.

It is my contention that, like France, the United States should create a nationally-owned agency to build and manage such reactors, and market the energy produced. We already did this sort of thing in the case of the Hoover/Boulder dam, and the Bonneville Power Authority.

France has been bullied by the EU into privatizing EDF, on grounds that amount to claiming that the electricity so produced is so inexpensive that private entities cannot compete. Even with that disadvantage, which ruined Britain's nuclear power projects, EDF now owns "British Energy", and has bought interests in nuclear power plants in the USA.

Facts:

  1. Nuclear power produced just under 20% of the electricity consumed in the USA in the years 2004..2007.

    For each of those years, uranium oxide needed for US nuclear reactors is reported at close to 50 million pounds a year.

    That's 25 thousand tons a year, of the oxide. Assuming it's U 3O8 that contains about 21 thousand tons of the uranium element. Trifling compared with the thousands of millions of tons of coal burned, and the even larger quantity of carbon dioxide (more than three times as much as the carbon) produced by it. In fact, every million tons of coal burned produced several tons of uranium and thorium oxide, both slightly radioactive, in the ash.

  2. Most of the uranium loaded into nuclear reactors presently running is thrown away in the "nuclear waste." Perhaps 4% of the uranium is actually consumed.
  3. All nuclear reactors fueled by uranium produce fissile plutonium. Some of it is consumed by fission, and provides its share of the energy output. Some of it is converted to the isotope 240, making it useless for bomb production.
  4. The USA has a ban on reprocessing. The ban is a mistake, it makes disposal of plutonium impossible.
  5. The price charged to utilities for reactor grade enriched uranium does not include the costs of the miserably inefficient disposal methods decreed by various government restrictions. This accounts for the idea that uranium and plutonium recovered by reprocessing isn't economic.
  6. Natural uranium is more abundant than gold, silver or mercury, about the same as tin and slightly less abundant than cobalt, lead or molybdenum.

  7. The proportion of 235U in natural uranium is very close to 0.7%. So 140 tons of refined uranium contain one ton of 235U
  8. 235U, 233U, and 239Pu are fissile isotopes. We can regard these as a fairly scarce resource.
    The first is difficult to isolate. The other two are almost non-existent on the present Earth, but they can easily be synthesized in a reactor from the more common 232Th and 238U.
    Fissile isotopes are therefore a renewable energy resource, and more sustainable than forests in the face of profligate human energy demands.
  9. The USA had 280 thousand tons of stocks of depleted uranium in 1999.
    In 2007, it was 492 million kilograms, which is a bit more than 500 thousand US tons. Obviously, if we could "burn" all of that up to make energy, and not throw away so much uranium as "nuclear waste", the energy problem is solved.
  10. The USA funded the development, at Argonne National Labs, of the most advanced breeder reactor in the world, but cancelled it in 1994. The IFR was probably superior to anything any other country has produced yet.
  11. There was, a few years ago, an account of the IFR project at the Argonne lab's website. I cannot find it any more. There was one at Berkeley U. also, and you have to dig into their archives now to find it. I am suspicious enough to wonder why.
  12. The funding for bin Laden, and probably most Islamic terrorist groups, comes from petroleum revenues. Well, perhaps it's not a fact, but it seems very probable.

Assumptions:

more recent data
  1. The 50 million pounds was natural uranium oxide, unenriched. That's 25,000 tons.

  2. Let Q be the average mass of enriched uranium consumed annually for electricity production, including what accumulates as "waste".

  3. Let e be the proportion of 235U in the total uranium of the fuel rods. It's about 3.6%, so the enrichment factor e for fuel grade uranium is e/0.7, which is near enough .51

  4. It follows that for every ton of reactor uranium, there are at least six tons of depleted uranium, I.e. seven tons were mined and refined to metal. That's if you extracted all of the fissile isotope from the depleted portion. But in fact, if depleted uranium is 0.3% 235U, it takes six or seven tons of uranium to make one of fuel grade, because only 0.5% of the 0.7% is transferred. According to the French site
    http://www.francenuc.org/en_sources/sources_unat_e.htm
    depleted uranium was 0.25% 235U for at least one instance.
    So Q is probably about 5 million pounds (or less), i.e. about 2,500 tons.

  5. Let f be the proportion of fissile isotope 235U turned into fission products, actually producing energy. The uranium actually consumed is therefore Q.e.f
    (The quantity consumed in the reactors) times
    (the enrichment figure) times
    (the proportion of 235 U consumed)

  6. Suppose f is as high as 4/5. Then 20% of the USA's annual electricity consumption required about 4/5 times 1/20 of Q. That's one twenty-fifth, 4%, of Q. So the actual amount of uranium consumed, and the mass of the fission products, amounts to only one hundred tons a year.

  7. This process throws away 96% of the fuel rods, and ignores the depleted part of the uranium mined.

Now consider a Fast Breeder Reactor, totally self contained except for importing its first fuel load, and a supplement of natural or depleted uranium. Once every 50 years it would export its tired old fission products for disposal.

Calculation Based on these Assumptions

These are guesses, and approximate. But they're probably not off by a factor of as much as 2.0

  1. Suppose we used the IFR to convert progressively all of the 238 U to fissile fuel, recycle and fission it.

  2. Annually, depleted uranium = 5/6 of 25,000 tons ~= 21,000 tons.

  3. Suppose we had a number of reactors that converted just enough of the non-fissile uranium into fissile plutonium, and didn't make it available outside of the reactor. See Advanced Reactor Concepts

  4. Such a reactor would produce just enough plutonium in one fuel cycle (several years) to let each fuel rod be reprocessed and replenished with a supplementary charge of depleted or recycled reactor uranium, and continue for another cycle.

  5. In March 1995, approximately 200 Metric Tonnes of U.S.-origin weapons-usable fissile materials were declared surplus to U.S. defense needs.

  6. With the backlog of "waste" from 10 years, and the stocks of depleted uranium from reactor fuel and nuclear weapons manufacture, and of bomb grade enriched uranium and plutonium already declared surplus to our "defense needs", we could supply enough reactors to power the entire USA, hydrogen economy included, for at least a century, without either mining or enriching any uranium. see Updates At the same time, we'd reduce the waste storage problem per gigawatt-year by a factor of 20 in volume, and about a thousand in duration.

The assumptions above as to quantities are probably pessimistic. The amount of depleted uranium available is probably twice what I assume. The amount of plutonium that is unnecessarily still devoted to our monstrous commitment to 'defend' ourselves with nuclear weapons is presumably a military secret.

Finally, if Q= 5 million pounds per year, that's 2.5 thousand tons a year. With the approximate assumptions above, the current annual production of actual fission product waste is one hundred tons a year, and would be five hundred if all of our electricity supply were fast nuclear. Various estimates of our total energy consumption are about six times our electrical energy consumption, which would require sequestering 3,000 tons of fission product waste annually, a decidedly easier job than sequestering thousands of millions of tons of carbon dioxide gas.


Updates

New, actual data on enriched fuel

EIA Uranium Marketing Annual Report For 2009, the total uranium required for civilian purposes was 49.8 million pounds U3O8 Equivalent That's near enough 42.2 million pounds of uranium, not more than 0.7% of it 235U. Call it 21,100 tons, of which about 148 tons is fissile. Those 148 tons of fissile isotope supplied all of the 20% of our electrical demand that is accounted for by nuclear power plants.
But in fact about 1/3 of the fissile isotope ends up in the depleted fraction, and only about half of what goes into the enriched fuel is actually consumed before the fuel rod is "spent" So it's more like 50 tons of actual fissile uranium being consumed. However, it is reported that one third of the power produced comes from plutonium derived from the U-238 by neutron bombardment. So count that as 25 tons of Pu-239 consumed. There's probably 25 tons of Pu-239 left in the "spent" rods. Moreover, because the energy from nuclear fission comes solely from the difference in mass between the "fuel" and the fission products, the fission products, the strongly radioactive waste, weigh microscopically less than 75 tons.

Actual data on depleted uranium stocks

According to the anti-nuclear World Information Service on Energy:
In 1999, the USA had stocks of depleted uranium amounting to about 480,000 tonnes.
They also have dire predictions about the supply of uranium for our present wasteful nuclear technologies
But their calculation of the cost of one gigawatt-year (GWa/e) of nuclear supplied power reveals that the widely alleged "carbon cost" of producing fuel enriched to LWR reactor grade is a mere 4% of the energy generated, assuming that the electricity is from coal-burning and gas!

Divide 480,000 by 75, and multiply by the 8% of the USA's annual total energy demand that is met by 75 tons of U-235 and Pu-239. We get over 500 times the present annual energy consumption in the USA! That's what complete reprocessing of the depleted uranium in breeder reactors would provide. It's certainly over 200 years' worth of our total energy consumption. Am I doing something wrong? Well, suppose we take a year's worth of the natural uranium fed to the enrichment plants. I'm supposing that it could all be used, instead of just the 0.4% which is U-235 that makes it into the reactors. That would be a factor of 500. (!) But natural uranium is 0.7% fissile isotope? Yes, but the depleted uranium is still 0.3% fissile. The cost of extraction from the steadily weakening depleted stock gets uneconomic.

Caveats

  1. You can expect fierce opposition to a serious attempt at putting coal and petroleum out of business. There hasn't been much opposition to solar, wind, and biofuels from them, other than scoffing, because they know that such technologies are no threat!
  2. There's not much incentive here for "private enterprise". The US government has already taken on the currently infeasible liability for disposing of the "waste", including the real waste, so the whole program should be nationalized.
    It is, after all, the Moral Equivalent of War.
  3. To meet the actual peak demand, we'd need enough reactors that some would contribute only part of their capacity to the grid.
  4. Nukes are happiest at full load, so the obvious solution is to make hydrogen electrolytically with the capacity not being employed for the actual electric demand.
  5. Another option is to build hydroelectric pumped storage projects to meet peak demand with pumped water.

    Pumping water uphill is incidentally the only way to make use of energy from wind turbines, but you still have the visual pollution of the wind turbines, and the dead bat and bird bodies.
    600-foot high wind turbines and their bird slaughter will be less noticeable offshore, until you find that the bald eagle, pelican, osprey, and albatross populations are depleted.

Scottish moor
Note the size of the vehicle. This is a Scottish moor.

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