site, A Site in Area 11 (Plutonium Valley), have since become avail-
able and are analyzed in the present report.
These data include
239-2405, 241an 2344) 2354 2364 and 238y for soil and/or vegetation.
Approximately 50% of the data have still to be reported, but
+
the available results
estimate:
(analyzed by LFE Laboratories)
(1) average concentrations of
239-2405,
are used here to
235y
an
random soil and associated (adjacent) vegetation samples;
concentrations of 2347 |
in vegetation samples;
d 2381, in
(2) average
2365 and total u (734y + 235y + 236y 4 7238p)
(3) the inventory of 2354, 2387
and 239-2405, in surface (0-5 cm depth) soil;
2351 + 238 U,
(4) the relationship
between soil and associated vegetation samples for 2354 and 238), and
(5) the change in concentrations of
2355
2385
and 239-240
Pu with
depth of soil for four profile samples.
The remainder of this report concerns a comparison of plutonium and
americium concentrations in different "fractions" of the soil matrix
in samples collected from Area 13 and the Tonopah Test Range as part
of the inventory sampling program.
This information is particularly
relevant at the present time since the three analytical laboratories
currently performing radiochemical analyses for the NAEG have been
sent either ball-mill
Hence,
(BM)
or sieved soil fractions for analysis.
the question arises whether the reported results from the
three laboratories are really comparable,
fractions contain (on the average)
concentration?
i.e., do the different
different levels of plutonium
That this might be the case is suggested by Tamura's
(1974) work on the distribution of plutonium in different soil fractions.
If there are differences in plutonium concentrations in
different soil fractions,
then changes may be required in soil prepara-
tion procedures so that all laboratories receive the same soil fraction for analysis.
Information is given here on plutonium and americium concentrations
in the following soil fractions:
mesh."
"ball-mill," "<100 mesh," and ''>100
A BM aliquot is one taken from the sample after the sample
has been oven dried at 65° C.
for 12 hours (allowing the sample to
reach standard dry weight) and then ball-milled for 5 hours in a
gallon can with ten l-inch manganese forged steel balls per sample.
A "<100 mesh" ("sieved") aliquot is one taken from BM soil that has
passed through a 100 mesh sieve (2 or 8 inch).
119
Finally, a ">100