[cdn-nucl-l] fast reactors for Canada ??

["Jaro" <jaro-10kbq@sympatico.ca>]

A couple of articles in the two most recent issues of the CNS Bulletin (
http://www.cns-snc.ca/Bulletin/bulletin.html ) tout the benefits of fast
neutron reactors in ensuring that nuclear fission becomes an essentially
inexhaustible energy source.
The implication is that thermal neutron reactors cannot achieve fissile fuel
"breeding," hence the eventual need for fast reactors, as cheap sources of
uranium begin to run out, in the latter part of this century (a similar
article is posted at
http://www.computare.org/Support%20documents/Fora%20Input/CCC2006/Nuclear%20
Paper%2006_05.htm ).

In fact however, thermal reactors -- heavy water reactors like CANDU in
particular -- can be modified to operate as breeders of fissile fuel (U233
from Th232, with BR > 1.0), if absorption of neutrons by fission products is
avoided -- as in replacing the shuffling of solid fuel bundles with
circulation of liquid fluoride salt, plus on-line chemical processing to
remove FPs (as in the old Molten Salt Breeder Reactors, but using D2O
instead of graphite, to avoid the problems of the latter - not least the
production of C14, with T½ = 4 ky).

The use of fast reactors for fissile fuel production entails spent fuel
reprocessing, a task that is made more complicated compared to fluid fuel
reactors, because *solid* fuel needs to be processed and then re-fabricated
to solid fuel elements again.
For more, see "Energy from Thorium" at http://thoriumenergy.blogspot.com/


 Jaro
^^^^^^^^^^^^^^^^^^^^^



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