Nuclear fuel recycling in the United States
Earlier this month an editorial was posted on GreenvilleOnline.com titled Nuclear reprocessing is risky and impractical, laying out the case against recycling of nuclear fuels (or at least the case against conventional methods for recycling of conventional nuclear fuels). (Thanks to Atomic Insights for the story tip.)
The editorial states:
Nuclear reprocessing separates plutonium from radioactive waste so that it can be reused to generate additional energy. However, reprocessing also has an unfortunate side effect: It dramatically increases the volume of radioactive waste.
Of course, if the alternative to nuclear fuel recycling is to take all the used fuel and label it as supposed “waste” material, and of course that is the alternative, then it’s a universally accepted fact that of course recycling of the nuclear fuel reduces the volume of material that is considered “waste”.
Typical used fuel from a typical LWR with a LEU fuel consists of approximately 96% uranium-238 and 235, which is completely unchanged in the reactor from the original fuel, about 3% of fission product nuclides, about 1% of plutonium, about half of which is plutonium-239 and half of which is comprised of other plutonium nuclides, and small trace quantities of other actinides, including a little U-236, U-232, Np-237, Am-241 and what have you.
Even if nuclear reprocessing involves only taking the uranium from that nuclear fuel, then immediately, with uranium separation alone, you’ve removed 96% of the mass of the radioactive “waste” that you need to deal with – and that’s without any consideration of the valuable, useful materials which constitute the other four percent.
If “nuclear waste” is such a terrible concern, the the first thing that should be done is to make sure we’re not wasting it.
The separation of plutonium is not necessary in any way for the use of nuclear energy, nor is it required at any point for the efficient recycling of used uranium fuels. The separation of plutonium, contrary to popular belief, is not the point of nuclear recycling. Separation of plutonium is an integral part of nuclear weapon building, and it is certain technologies which were developed for this latter purpose which have, historically, been applied to the recycling of power reactors fuels.
To construct a nuclear fission weapon from plutonium does indeed require the chemical separation of pure plutonium from uranium irradiated within a nuclear reactor – but that’s the only thing that requires separation of plutonium. This is why separation of plutonium, or the possibility of it, seems to be viewed with distrust and suspicion, especially at the Savannah River Site, perhaps, given its historical mission of the production of weaponisable plutonium via nuclear reactors and PUREX extraction.
Even if you want to use plutonium from used civilian reactor fuel efficiently, and recycle it back into the recycled nuclear fuel, where it serves as a potent, valuable energy source, chemical separation of plutonium is not needed. Even though most established, mature efforts for the recycling of nuclear fuels at the industrial scale involve the PUREX process, which was designed and established specifically to support the production of separated plutonium for nuclear weapons, there is no reason why this process is essential at all. It’s quite straightforward to modify the chemistry of the solvent extraction process so that the plutonium is kept combined with the other actinides, so that this material can be recycled into new nuclear fuel without any material being produced that presents any proliferation risk. That is what is done with the COEX or DIAMEX chemical processes, and what can be done even better via pyroprocessing or in-situ separation of nuclear poisons in a molten salt reactor.
Even if the potential for diversion and weaponisable plutonium was considered so grave that we were insistent of taking the plutonium and disposing of it in some kind of deep geological repository, this would only constitute 1% of the fuel – so, we wouldn’t be losing much of the fuel, really. However, plutonium-239 is a moderately long lived nuclide – with a half-life of 24,400 years, it doesn’t just go away overnight if put in a geological repository. So, in decades to come, the material could still be removed, and weaponised.
The only proper way to get rid of plutonium, if you’re really concerned about nuclear weapons proliferation, is to fission it in a nuclear reactor – and, lo and behold, you get plenty of clean, safe energy to boot, at the same time.
According to the Union of Concerned Scientists, “After reprocessing … the total volume of nuclear waste will have been increased by a factor of twenty or more ….”
Of course, that’s simply absurd. What sort of definition of reprocessing are they using? What evidence is provided for such a claim?
For instance, discharges of iodine-129, a very long-lived carcinogen, have contaminated the shores of Denmark and Norway at levels 1,000 times higher than nuclear weapons fallout.
Well, does that tell us anything? What is the background dose rate to the public as a result of the nuclear weapons fallout, and what is the contribution added to the dose rate to the public as a result of nuclear fuel reprocessing?
Health studies indicate that significant excess childhood cancers have occurred near French and English reprocessing plants.
Is there any peer-reviewed, scientifically motivated, literature which demonstrates the existence of such excess childhood cancers, and demonstrates, or even reasonably motivates, a causal connection between the two?
In 2003, for example, researchers from Harvard’s Kennedy School of Government said that reprocessing costs more than twice as much as safe, on-site interim storage of nuclear waste.
The report cited, from the Belfer Center for Science & International Affairs at Harvard University, The Economics of Reprocessing vs. Direct Disposal of Spent Nuclear Fuel, states:
At a uranium price of $40/kgU (comparable to current prices), reprocessing and recycling at a reprocessing price of $1000/kgHM would increase the cost of nuclear electricity by 1.3 mills/kWh. Since the total back-end cost for the direct disposal is in the range of 1.5 mills/kgWh, this represents more than an 80% increase in the costs attributable to spent fuel management (after taking account of appropriate credits or charges for recovered plutonium and uranium from reprocessing).
Furthermore, the editorial’s authors continue with much the same assertion:
In 2007, the National Academies of Science (NAS) noted that no reprocessing technology currently on the table “is at a stage of reliability and understanding that would justify commercial-scale construction” and the report therefore concluded “there is no economic justification for going forward with this program at anything approaching a commercial scale.”
The nuclear industry has reached a similar conclusion. A 2007 report by the Keystone Center, underwritten by various utility companies, said “reprocessing of spent fuel will not be cost-effective in the foreseeable future.”
The “reprocessing is not economically competitive” argument basically boils down to the idea that recycling the used fuel is more expensive than the inefficient, once-through use of newly mined uranium.
People are frequently concerned about the environmental intensiveness of uranium mining and the handling of radioactive wastes from nuclear power – and yet recycling and efficient re-use of nuclear fuels minimise the requirement for both of these things. To me, the argument against recycling because recycling costs more is ridiculous, and it’s essentially equivalent to eschewing the use of alternative energy systems in favor of more coal, because coal is cheaper.