ORNL-TM-7207 - the Molten Salt Energy Technologies Web Site

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.=w as SSm, Amore attractive isotopic mixture would exist early in the
95
plant lifetime (e.g., after one year of operation), but the total inven-
tory WQUM be nueh smaller - only 86 kg oi 23%u =+ 24bpu with 13 kg of
24(4Pu + 2%u,
hother potential source of SSNM in a DMSR would be 233~a. T~FS nu-
clide would have its maximum inventory of -63 kg early in the reactor
life and slowly decllbne to about 41 kg at the end of life, In principle,
this nuclide, if it could be cleaga~y and rapidly separated from the res%:
of the fuel salt, could provide an equivalent amount of high-purity 23%
through simple radioactive decay.
3.%,2 Accessibility sf SSMM
A major consideration regarding the accessibility of various foms
of potential SSm in a DMSR is that all the materials are intimately mixed
with -350 Mg of highly radioactive fuel salt with no known method for
simple physical separation.
nus, diversion of only a modest amount (a
few kilograms of SSNM without plans for isotopic enriebent would require
the removal of a number of tons of fuel salt from the reactor system. The
need for such large (and otherwise unjustifiable) salt removals, which
without rep~lacenent would shut d ~ m the reactor, couple$ with the need for
an elaborate chemical treatment facility to isolate the produet appears
to make this approach relatively impractical.
In princfpal, pure 233U could be diverted via the 233Pa route by
modifying the in-plant hydrofluorinator to permit ita use as a fluori-
nator. This would requlre two fluorinations of each batch of salt, with
one occurring immediately after removal of the salt from the reactor to
strip out the denatured uranium and a second about two months later to
recover the 233U produced by 233Pa decay. However, i f the system were
originally designed to handle batches si salt no larger than -1 m3, the
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* Presumably, this approach would be rased only to divert plutonium
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because uranium diversion wou~d
require isotopic enricbent and 23 +a
diversion would encounter serious timing problems, as well as requiring
the handling of more salt.
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