consists of two pods mounted on a helicopter or light aircraft.
contains 20 5" x 2" Nal crystals.
Each pod
The signals from these detectors are
summed and submitted to a data acquisition system.
The output is monitored
py 8 single channel analyzers and a multichannel analyzer for gamma cpectral
analysis.
whose
Also included in the system is an inertial navigation system
output is recorded simultaneously with the radiation data on magnetic
tape.
,
:
If the system were mounted on a helicopter travelling at 100 ft/sec,
the spatial resolution for 241an on the surface is approximately 100 feet
_when using the single channel mode of operation.
High energy gamma emitters
may be located with a spatial resolution of about 50 feet based upon the
accuracy of the inertial navigation system.
for 600, and 137 Cs
The minimum limits of detection
is about 1 4R/hr and approximately 1 pCi/me for
abla
The system may also be flown satisfactorily on small fixed wing aircraft,
but the spatial resolution is directly related to airspeed.
+o Cosadaa.
The total weight of the system is 1400 lbs and requires 3 people to
operate.
It would take approximately 1-3 weeks to complete the survey de-
pending upon meteorological conditions.
pr
2,
Aerial photographs of the islands may also be taken with a separate
EG&G system which incorporates four Hasselblad cameras equipped with 80 mm
lenses.
High resolution photographs obtained with this system are a
necessity in order to accurately identify locations where soil samples and
survey meter readings were obtained as well as to assist in assessing the
amount of cleanup that will be required.
Soil Sampling Program
The soil sampling program of the survey will be conducted in a manner
that will insure statistically meaningful results.
samples will be collected for analysis:
15 em deep cores of 30 ome area each; (2)
(1)
Several types of soil
A sample consisting of two
A surface soil sample collected
by a "cookie cutter” of 30 em? area to a depth of 5.0 cm; and (3)
A
profile collection based upon side wall sampling in a trench in which
complete samples of fixed horizontal area are taken to selected depths.
enmeninon materialePACER. ons
The increments of depth are chosen according to predicted, suspected, .
or known radioisotope concentration vs. depth relationships and also
according to any soil horizons present at the sample location.
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