+33-
Profile samples of the lagoon bottom were obtained off
Kabelle Island at depths of 60 feet and 40 feet and off Lomutlal
Island at 55 feet.
The samples were obtained by an aqualung-
equipped diver driving a foot long, 14"-aluminum tube into the
bottom sand.
The core was removed from the tube and samples
were taken at various levels.
From the counts of these samples
it was observed that the radioactive sand on the lagoon bottom
wieBRbet
Ee
was several inches thick with the level of activity rather constant for the first five or six inches.
The radioactivity per
unit weight was less than that of the soil from the island
proper but off Kabelle it was greater than that of the sand in
"
the tntertidal zone.
Water
The water collection included eight salt-water samples
from the lagoon and eight fresh-water samples from the
proper.
islands
A 5-milliliter sample was used for the radioactivity
determination except for the December 18th collection (cistern
water,
filtered well water), for which 25-milliliter samples
were used. Because the radioactivity of water samples is often
stated in terms of the radioactivity per liter, which would
mean extrapolation considerably beyond the observed values,
is especially
necessary to state the counting error.
it
For these
data the 0.95 counting error,” which is equivalent to two
standard deviations, was arbitrarily selected.
* AECU-262 (Mon P-126)
In Appendix
Statistical methods used in the measure-
ment of radioactivity (some useful graphs) - A. H. Jarrett,
T.I.S., Oak Ridge, December 1949.
tN.