Ses

0021620

(NTS soil) and the Tewa curve with Zuni curve (coral) indicates also

that the gross fractionation decreases with yield. No comparison can
be made between the coral and NTIS soil from these curves because of
the large differences in yield and distances.

A summary of corrected "R" values (i.e. corrected for mass chain
yield from U€3> t6 the fuel actually used) is given in Table 8 for some
Operation REDWING data.l2 A general increase in the "R" values with
distance is shown-for all the radionuclides in the Zuni and Tewa fallout. In Shot Flathead only the radionuclides with rare gas precursors

were fractionated. In Shot Navajo, there was no fractionation in the
fallout (within experimental error).
.

" Rough correlations of the "R" values of Table 8 with distance and

also those of References 19 and 20 with particle size (with aid of Eq.

14) can be made if a fractionation parameter, z, is defined as

te

(29)

where rj is the "R" value for the jth mass number (or nuclide) and,

. further, that

25+ 2,(d)e™

(30)

Although the data of Table 8 are somewhat scattered with respect to a
continuous change in rj or 23, they all can be adjusted, within about
the same degree of error, to Eq. 30 with the same value of k, for a
given shot. Substituting 1/a (inverse particle diameter) for x and using
the data of Reference 20 gives an even better fit for a constent k,.
If zfp is defined as the sum of all the z j of fission product mixture, then

Zen =e
= 2

ky

* z, z4(3)

kox
°
e
fp

pok/NY

(31a)

(31d)

o(

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