w
those shown for W-BeFZ mixtUres, the va;lues of Table 2.4 suggest that the ''snow" problem w i t h BeF2 mixf;ureS is much less severe thas with ZrF4 melts.
be higher
Physical proprty d u e s indicate tihat the mnlten fluoride salt?
'
*
hawever, am, in general, adequate heat transfer media. It is ap-nt, fwOn vapor pressure mxmmmentE3 and from spectrophotametric -tion of analogous chloride sys$ens that such melts have caqplex structws and are f&x from idea solutions,
4,
.
.
.
RhDIATION STABILITY
When fission of an active constitwant oocurs in a n1~1tenflu0rid.e solution, both electxwxuaguet3.c radiations and particles of very high energy arid intensity originate within the fluid, f n d overheating as' a consequence of rapid slowing down of fission fragments by the f l u i d
is probably of l i t t l e consequence in a reactor where the liquid is forced t o f'lmturbulently and where ragid a& intimate mixing occurs. Mmeover, the bonding in such liquids is essentially cqpletely ionic. such a solution, which has neither covalent bonds to sever nor a l a t t i c e to disrupt, should be quite resistaat t o dwnRge by particulate or eledt-etic radiation.
s
@re than 100 exposures to =actor radiation of mixbums containing UF4 in capsules of Inconel have been c6
these tests tibe fluid was not deliberately agitated. The pazer kvel content of the t e s t mixt&. of each t e s t was fixed by eelecting the Themaal neutron fluxes hsve m d f mlou t ~ ' ~ 14 p O neutamns/cza20sec
,
.
and power levels have varied fram 80 t o 8OOO w/cm3, . The mps i n general, been exposed at 1500°F for 300 hr, ₏iJ.thse7ieral tests have been conducted for 600 t o 800 hr. A l i s t & the makerials %bat have been studied i s presented i n Table 2.5. Methods .of eXamination7of the . fuels a t e r irradiation have included (1) freezing-point detenninatiozis, (2) ch@ca;l. analysis, (3) examiaation with a shielded pet+graphic
- .
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- 100 ..
,
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.