Energy From Thorium Discussion Forum

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PostPosted: Nov 16, 2008 8:53 am 
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jaro wrote:
As regards "Dry cask storage is as expensive as a parking lot," that is of course incorrect:
Besides the development and licensing costs, the actual equipment cost is on the order of several million dollars per unit -- depending on unit size (the larger units cost more, but are cheaper on a per-ton-SNF basis; unit costs must also include a share of site prep costs, heavy gantry crane and/or cask hauler, shielded loading flask, etc.).
Operating costs include monitoring of containment, and of course security.
A helluva "parking lot," if you ask me....

Now you're being pedantic. Fuel storage costs of several million for a 5 billion dollar reactor aren't exactly a serious expense. Doing reprocessing of this fuel is far more expensive, especially with discounting.

Dont get me wrong, I see the appeal in breeders and am a fan of a closed fuel cycle, but we musn't blind ourselves to threats to the competitiveness of breeder reactors. The rationale of a closed fuel cycle isn't that uranium is in any sort of short supply ever, nor is it that spent fuel is costly to store, because it isn't.


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PostPosted: Nov 16, 2008 9:06 am 
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dezakin wrote:
In several centuries we can use a better solution, or just reseal them at near zero cost because of discounting.

Typically, these dry SNF storage casks or modules are designed for 50 to 100 years endurance - at least for licensing purposes.
They will undoubtedly last longer than that, but the concrete does weather over time, especially in northern climates and in salty air close to sea, so there is little likelyhood of "just reseal them at near zero cost".
In 50 years - if not sooner - SNF reprocessing is likely to be pretty common, so its unlikely these storage modules will be rebuilt.
Then there will be decommissioning costs....

An interesting aside: AFAIK, no utility that uses dry SNF storage has installed them below ground (though a few use buildings to house the modules).
The complication that underground installation would impart on the natural draft ventilation, plus a host of other issues, makes it about as attractive as installing windmills underground, to avoid NIMBY problems....


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PostPosted: Nov 16, 2008 8:52 pm 
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One disadvantage of storing SNF is that the Pu241 decays. It has a half-life of 14.4 years. It is excellent fuel. But it decays to Am241 which is pretty poor fuel. So, there is a reason to prefer to recycle sooner rather than later if we are concerned about long term storage of minor actinides.

For those concerned about Pu bombs (I'm not one of them but I know such people exist) extracting the Pu from the SNF and putting inside the LFTR will consume most of the Pu and make the remaining unusuable for bombs.


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PostPosted: Dec 06, 2008 11:13 pm 
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Expansion of Indian nuclear capacity is once again in the news. As expected, closed cycle including fast breeders and thorium fuel form an important part. Uranium mining is also a part but problems including development time and NIMBY politics are not overlooked. Closed cycle is also a part of nuclear policy of France, China, Russia and Japan covering in total more than half the world population. Obviously in eyes of more than half the world, once through use of uranium (or rather .7% 235U) cannot meet the demand of all the reactors but properly developed, 238U and thorium can. Gen-IV and INPRO also consider closed cycle. It is only the die-hard anti-proliferation Ayatollahs who continue to frown on closed cycle.


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PostPosted: Dec 07, 2008 5:29 am 
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Lars wrote:
... and make the remaining unusuable for bombs.


SNF from LWRs are already not usable for weapons, at least in the sense that the (sci-fi) technology necessary to reprocess/machine/put together a functioning warhead from RG-Pu is insanely more complicated (if possible) that the standard practically textbook 60 years old well known and tested route/s/, both of which precede and thus are totally independent of nuclear power for electricity. Thus the fear that expansion of nuclear energy production will in any way increase proliferation risk, is illogical.


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PostPosted: Dec 07, 2008 7:21 am 
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jagdish wrote:
Expansion of Indian nuclear capacity is once again in the news. As expected, closed cycle including fast breeders and thorium fuel form an important part. Uranium mining is also a part but problems including development time and NIMBY politics are not overlooked. Closed cycle is also a part of nuclear policy of France, China, Russia and Japan covering in total more than half the world population. Obviously in eyes of more than half the world, once through use of uranium (or rather .7% 235U) cannot meet the demand of all the reactors but properly developed, 238U and thorium can. Gen-IV and INPRO also consider closed cycle. It is only the die-hard anti-proliferation Ayatollahs who continue to frown on closed cycle.

Never let the facts get in the way of your opinions. Uranium is log normal distributed, stockpilable, and cheap, and I've posted several studies showing that.

There are distinct advantages to thorium cycles that we can focus on without resorting to being disingenuous or simply outright wrong.


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PostPosted: Dec 08, 2008 7:32 am 
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The problem with an open-cycle approach is that we will be accumulating too much nuclear waste. This is all the more so,when you consider powering the entire world with nuclear. An open cycle is simply not an option, because it magnifies the proliferation worries - whether we have enough Uranium to mine or not.

A closed cycle will even absolve us of the need to mine more U-235. What is the easier option ?


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