not profoundly affected by U-232 or U-236.
The reference is found in William Stacy's "Nuclear Reactor Physics" John Wiley and Sons and I will elaborate just a little below to dismiss this absurd claim.
First let me quote this nuclear engineering text, page 236, in the chapter on fuel burn-up:
Although it is relatively straightforward to separate uranium form other chemically distinct isotopes, it is impractical to separate the various uranium isotopes from each other in the reprocessing step. So recycling uranium means recycling all of the uranium isotopes, some of which are just parasitic absorbers, another of which leads through subsequent decay to the emission of an energetic gamma.
Two isotopes present in relatively small concentrations in fresh fuel 234U and 236U necessitate adding 235U to enrich reprocessed uranium to higher enrichment than is required with fresh uranium fuel.
This pretty much disposes of the claim that reprocessed uranium is "worthless." Note that
239Pu can substitute for
235U in the enrichment scheme, as can
233U, obtained from thorium. In fact, the the
233U case, there is an advantage to using recycled uranium, inasmuch as this acts as a significant diluent further minimizing the small probability of weapons diversion. If
233U is diluted with recycled uranium, any plutonium resulting from the burn-up will further be denatured with
238Pu, complicating any attempt at weapons design.
Stacy writes further:
Only about 1% of the energy content of the uranium used to produce fuel is extracted (via fission) in a typical LWR fuel cycle. About 3% of the energy content of the mined uranium is stored as tails from the original fuel production process and about 96% remains in the discharged spent fuel in the form of uranium, plutonium and higher actinide isotopes. With continued reprocessing and recycling of spent fuel, there is a possibility of recovering much of this remaining energy... (page 233-234)
...Processing of spent UO2 fuel to recover the residual U and Pu reduces the potential long term radiotoxicity of the remaining HLW (minor actinides and HLW).
Finally he writes on page 236:
A fuel cycle in which the recovered U and Pu reactor fuel was recycled as a mixed oxide (MOX) UO2-PuO2 has been envisioned since the beginning of the nuclear energy era, and at present a number of commercial reactors are operating with recycled Pu in Western Europe. (Reprocessed uranium is not being recycle significantly because of the low cost of fresh uranium, which does not contain the neutron-absorbing 236U that decreases the reactivity of the recycled U.)
In other words, uranium recycling is not significantly used because cheap uranium is so
cheap. It follows that uranium is
cheap because it is so readily available.
Thus we see that the anti-nuclear argument contradicts itself. On one hand it wants you to believe that the world is running out of uranium. If this were true, of course, shrill anti-nuclear people would have no problem and would not find it necessary to raise so many specious and ill informed specious objections to nuclear energy. Nuclear energy would simply just "go away" as they have been predicting it would for decade after decade after decade with their usual level of disconnection from reality.
The fact is, that the world is
not running out of uranium and people who are irrationally afraid of nuclear energy will be forced to live with their irrational fear, just as acrophobics sometimes must be in high places and agoraphobics sometimes must be in open places.
Now let's deal with the "Wise" website. Wise is one of the chain of self referential websites that continually use increasing desperate arguments to attempt to make more and more irrational misrepresentations about why nuclear energy won't work. They seem to know how to handle google to get their nonsense to pop up early, but of course, this has nothing to do with whether or not they have the remotest clue about the real situation. Of course, what they need to
ignore is that nuclear energy is working - on an exajoule scale - and working quite well. One of the most common practices of these websites is to attempt to use pseudo-technical language to represent that nuclear technology is
impossible because of x or y or z. The isotope argument I address here is just one such appeal. There are many others. In so doing, of course, they rely on the reader's ignorance of the real situation; in short they depend on the reader's
ignorance. If one actually knows what one is talking about, it is easy to dismiss these representations for what they are: Nonsense.
The ready availability of cheap uranium has eliminated the need for uranium recycling up to the present time, but many nations are taking steps to assure that their spent uranium remains available for future use when uranium prices rise, as surely they will, since the world has rejected the luddite anti-nuclear position because of global climate change. When the time comes, there is some
small technical consequences that will translate into somewhat higher prices, but these costs are trivial when compared to the cost of having no energy or, worse, having a destroyed atmosphere. My personal feeling is that we should commence with the use of this technology
now so as pay our own way - rather than asking our children and great-great-great grandchildren to pay the costs, but that's just my opinion.
Most countries in the world do recognize that uranium may not be cheap forever, however: The current price is the equivalent of gasoline at much less than a tenth of cent per gallon. For this reason, there is a slow but steady increase in the number of countries that are keeping spent fuel or isolated uranium
accessible to provide options for the future. It has been shown through experience that spent fuel can be stored above ground in casks for long periods of time with no loss of life or environmental damage of any kind. At some point uranium prices will rise high enough to make the payment of the reactivity penalty for the use of recycled uranium an economically acceptable thing to do. But we are a long way from that day.
I want to put forth a caveat that I often neglect in my discussions of the huge uranium and thorium resources available: It does not follow that since we have a large resource of this type that we should proceed as we have been doing for the last century or so. It is important to
reduce our demand for energy, as important as providing energy in the first place. We cannot and should not live like drunken sailors, simply because we have energy resources. Uranium and thorium resources
may be effectively infinite and then again, they may not. We should not therefore be wasteful. It is important to recognize the impact of uncontrolled population growth and that irrespective of the situation with energy, there are many other resource issues that are more problematic to solve.
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