Table B-2-3. Post-Cleanup TRU/Am Ratios on Irene

Location

TRU/Am

13-N-2
12-N-2
9-5-3
12-N-1
14-N-1

8.48
6.57
7.70
7.34
9.36

10-N-1
7-8-3

10.23
11.39

§-S-2

6.06

DETERMINATION OF THE PLUTONIUM TO AMERICIUM
RATIO IN SOIL SAMPLES FROM ISLAND VERA
DOE/ERSP TECH NOTE NO. 2.2

DATED: 21 November 1977

AUTHOR: B. Friesen, DRI

Reference Tech Note 2.0 for introductory remarks.
Determination of

one

mean

ratio

for

Vera

was

made

including

238,239,240py

and

24lam,

Laboratory results of eight soil samples taken from four locations on the island were used to
compute a ratio for each sample. The weighted mean of these eight numbers was 1.55 with a
coefficient of variation of 17.7%. The range in values was 1.26 to 2.09.
Determination of the error term to associate with the mean ratio was accomplished as described in
Tech Note 2.0. The Vera data has a weighted mean ratio and error term of 1.572+0.415, as

presented below, and these were used in the computations to derive total plutonium estimates and
upper bounds.

"A" Samples
Ratio No.
1
3
5
7
Simple Mean

Weighted Mean
Weighted Mean

(all samples)

"B" Samples
Ratio

Ratio No.

Ratio

2.09
1.73
1.62
1.60

2
4
6
8

1.26
1.32
1.33
1.45

1.76

1.34

1.77

1.34

1.572

B-2-11

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