In addition to the samples. our Laboratory collected, personnel from Brookhaven National Laboratory collected samples, made TLD measurements and took
radiation survey readings with sodium iodide (Nal) scintillation detectors
and a pressurized jon chamber.
The results of the Brookhaven analyses and
measurements may be combined with the LRE results in a series of joint
reports to the open literature.
ANALYTICAL METHODS
Gamma-Ray Spectrometry
All of the samples were analyzed by gamma-ray spectrometry, either with
a 3 x 3 inch sodium iodide (thallium-drifted) crystal and 200-channel, pulseheight analyzers or with a germanium (lithium-drifted) diode detector and
4096-channel, pulse-height analyzer.
Soil samples were analyzed on the
Ge(Li) system, and the biological samples were analyzed on both systems.
Al] samples were oven-dried, ground and a portion compressed in polyviny]
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chioride (PVC) pipe 2 inches in diameter and either '; or 1 inch deep that was
used as a sample holder for radionuclide measurement.
Fifty grams of tissue
or 68 grams of soil could be compressed into the 2 x } inch container.
The
densities of the biological and soil samples were 1.0 and 1.35, respectively.
These samples were then analyzed for gamma-emitting radionuclides.
The gamma-emitting radionuclides in samples counted on the Nal crystal
were determined by a method of least squares.
The radionuclides values in
samples counted on the Ge(Li) detector were calculated manually or with a
computer by adding the counts in an energy range of five channels under a
peak in the spectrum, subtracting the appropriate background counts, and
applying correction factors to convert counts to picocuries (pci).
A set of
previously reported reference spectra for the different geometries and
radionuclides was used.
collection.
All values were corrected for decay to the date of
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