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The exsct soi} sampling locations will actually be determined by &
random selection process to obtain statistically meaningful end unbiescd
results. Special samples will also be collected within "hot spot” areas
or other areas of specialized interest. The samples will be placed in
plastic bags with oppropriate identification tags and readied for shipment
to LLL, where they will undergo preprocessing and ganms-spectrel analysis.
It is enticipeted that analyses for other radfonuvciides of interest, such
as, pluton{um-239 and strontium-90, will be performed at 8 contractor
laboratory’.
’
Purpose:
Genms-Exposure Rate Survey
The ganins-ray exposure measurements program conducted on the ground is
designed to suppleinent the £G&6 aerial survey by providing detoiled
examination of the geographical variability of the exposure rates within
selective srcas, and to provide overall verification of #1) exposure rate
measurements made during this survey.
Hethads and Measurements:
“
The proorem utilizes the Baird-Atomfc scintillation detector which
consists of a 2.5-em-diem x 3.8-cm- long Hal crystal with ratemeter readout.
The instrument {s colfbrated with 3 §5/Cs point source on the primery calibretion range of the National Environmental Research Center, Las Vegas, Kevoda.
hile the response of this instrument 1s energy-dependent, our cxpertence
at Chewetsk shoved that this was not a serfous limitation because of the
dominance of
'13/Cs {n the radiation background on the atoll.
utilize the Reuvter-Stokes high pressure
fonizetion chamber,
|
Ke will 61s0
The current
produced by the rédtstion induced ionization within the chamber 4s measured
by & sensitive electrometer with digitel readout.
The instrument exhibits
a flst eneray response over 811 ganma-ray energies of interest to this survey.
It is capeble of messuring exposure rates from about 1 pR/hr to 200 uk/hr with
én accuracy of about 5%. Thus, the results derived from this instrument may
be chosen as a reference to which measurements obtained by other techniques
cén be compared.
,
HKeasurements of the exposure rate at 1 m above the ground will be made
with the Kal scinttllator at each of the soil sampling locatfons on both
tslands. The dontzation chamber will be primarily used for measurements
Within the central section of Bikini Istand with additional measurements to
be made st “hot spot" arcas revesled by the serfal survey. Thus, @ feiriy
comprchenstve picture of the gamma-ray cxposure rates will be aveflable for
both {stands from this program for comparison and validation of the aerial
survey results.
Bikini-Ground Rater Program
Purpose: To establish a network of tell locations on Bikini and Eneu Islands
n order to assess the ground water quality and to systematically study the
hydrology end geochemistry of radionuclides, major and trace elements in the
ground water syste,
Vater movenent and residence times ufl) be assessed to
deduce the transport rates and noechanisms for radionuclides deposited in the
sofl zone or taken up by vegetstion.
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DOE ARCHIVES