PLUTONIUM IN SURFACE SOILS OF AREA 13:
A PROGRESS REPORT
Tsuneo Tamura
Environmental Sciences Division
Oak Ridge National Laboratory
ABSTRACT
Analyses of three additional soil samples taken along a north-south
transect in Area 13 gave mean plutonium values of 324, 132, and 166
dpm/g for the samples taken at 1,910,
tively, from ground zero.
2,770, and 3,665 ft, respec-
In all three samples, more than 65% of the
plutonium was in the 53-20 um size fraction.
Comparison of particle size analysis of two soil samples (one under
shrubbery and the other without vegetative cover), with and without
ultrasonic dispersion, showed that in both soils,
contents increased with the treatment.
the silt and clay
The major change in plutonium
distribution following the treatment was an increase in contribution
by the medium silt size fraction and a decrease in the fine sand
contribution.
Although the field survey instrument (FIDLER) recorded
a higher reading for the sample under shrubbery as compared with
nonvegetated soil,
the analysis showed that the nonvegetated soil had
a higher plutonium content in the 0-5 cm depth.
INTRODUCTION
This report covers research progress during the 6-month period of
October 1974 through March 1975.
The objectives and scope of this
program have been presented in earlier reports
(Tamura,
1974,
1975a).