DETERMINATION OF THE PLUTONIUM TO AMERICIUM
RATIO IN SOIL SAMPLES FROM ISLAND IRENE
DOE/ERSP TECH NOTE NO. 2.1
DATED: 21 November 1977
AUTHOR: B. Friesen, DRI
Reference Tech Note 2.0 for introductory remarks.
Soil samples were collected from the surface and from 10 em and 20 cm depths at 5 locations on the
island of Irene.
Results from the laboratory showed high variation in the 238,239,240py to
24lam ratio, with the lowest values
west end. One intermediate value was
approximation estimates of total Pu
below. Soil sample locations and the
which this Tech Note is appended.*
on the east end of the island and the highest values on the
observed in the north central portion. In order to derive first
distribution, three separate ratios were used and are shown
areas for which each ratio apply are shown on the map to
"A" Samples
Ratio No.
1
3
5
7
9
"B" Samples
Ratio
Ratio No.
Ratio
2.85
4.67
9.43
9,21
12.45
2
4
6
8
10
2.54
5.64
11.63
7.59
10.60
Ratio Numbers
1-2
3-4
5-10
Simple
Mean
Weighted
Ratio Used
2.70
5.18
10.28
3.0 + 0.72
6.0 + 0.60
11.0 + 1.60
2.70
5.16
10.15
ADDENDUM TO TECH NOTE2.1: DETERMINATION OF THE RATIO OF TOTAL
TRANSURANICS TO AMERICIUM IN SOIL ON ISLAND IRENE
DOE/ERSP TECH NOTE NO.2,1-A
DATED: 6 February 1978
AUTHOR: M. Barnes, DRI
For the purpose of computing values of total transuranies from americium values, Irene was divided
into three distinct areas as described in Tech Note 2.1. In each area, using 0, 10, and 20 em soil
sample results, the simple mean and standard deviations of the ratios were computed.** These
values were then used in estimating quarter hectare average concentrations of total transuranies.
Area
Eastern End
Central Area
Western End
TRU/Am
4.12
6.50
11.13
Standard
Deviation
0.53
1.20
1.70
*Map omitted here.
**This method of estimating the ratio and error was later replaced by a method based on more
accurate assumptions as described in Tech Note 2.2-A.
B-2-8