i150
errors.
In addition, the only samples which snowed
239+240,
Pu/-~
238.
ru catios
mare than only slightly different from each other in absolute value
(samples B-16, B-22, B-27) were those with the largest relative
counting errors.
238
Pu
Because the error term in these first tyvo sets of
plutonium ratios arise mainly from the error associated with the
238
Pu
concentrations inaasured, these different ratics can be assumed cue to normal
variations in the low 2385, counting rates and/or an effect related to
the addition of the
236
Pu tracer (in the first case).
Since the
23€ Pu
concentrations measured in these three samples was tower than in the unspiked
sample, it is obvious that the tracer impurities were not resulting in
calculeted
238
Pu concentrations which were greater tnan were present.
Tne concentrations of
238 Pu
and
23942405 measured in surface
sediments are shown in Appenaix Table 5.
The
B0420C Fu
concentrations an¢d
measurement errors reported were cemputed for individual samples as previously
samples for which the ratios
The 2385, concentraticns in all but those
239+240,, 233
Pu were redetermined (stown
in /ppendix table 4) were calculated in a similar manner.
For these late”
samples, the ratio reported is the ratio comouted from the two analyses
by weighting each ratio ty its propogatad counting error (by the method
c
of Stevenson, Lop. cit.J; and a weighted mean ratio anc error was computed.
-.
ihe
Z
.
:
:
.
sey concentration in these few samnles wes then calculatec using the
equation in fuot note | on the previous page.
to this orocedure.
There were two excestions
No sample 5-19 or £-20 (Appenciix taole 4) remained
for a second plutonium analysis so that a second sample previcusly storea
as excess hed to he dissolved for the analysis, ana the semple was, in
ae
.
242
addition, spiked the
~“"Pe.
.
.
.
In the analysis, the fusion porticn of the
dissolving the sample procedure was inadvertently omitted.
Beceuse of
weerenete
explained (section 4.2-4).