One of the most important aspects of any research project is the analysis
of samples. LFE Environmental Analysis Laboratories pioneered much of
the methodology for analytical procedures for transuranics. Wessman,
Leventhal, and Melgard discussed the LFE support to NAEG as well as
other NTS environmental samples which have been processed by their
laboratory.
Wessman and Benz, LFE, presented a paper regarding the problems of
analysis of natural and artificial isotopes of uranium.
As the presence
of natural uranium isotopes in environmental samples is a general problem,
the reader is referred to their solution for accurate analysis of such
samples, obtained by balancing sample and tracer activity levels and
determining correction factors.
Sequential separation of 30sy, 239puy, and 23lam is a procedure discussed
by Lee and Straight of REECo.
The separation and purification of 90sr
requires a highly sensitive chemical procedure.
The basic work for the
REECo procedure was done by Sill, DOE, Idaho Operations, and extended by
T. D. Filer, Los Alamos Scientific Laboratory.
The estimation of spatial pattern or geographical distribution of environmental contaminants is a problem in many environmental sampling programs.
In NAEG studies, the concentration in surface soil distribution of
plutonium around ground zero at Area 13 needed to be estimated in order
to predict the potential hazard to man from this contamination in a
safety-shot area.
Gilbert of Battelle Pacific Northwest Laboratory
discussed the use of an iterative procedure for estimating grid values
(to arrive at the total estimated inventory) at regular intervals on a
grid covering the study site using data collected at varying locations
over the area.
Plots of sample data on estimated contour maps suggest
locations where more data should be collected.
Delfiner, Centre de Geostatistique in Ecole des Mines de Paris, and
Gilbert, Battelle's Pacific Northwest Laboratory, completed a joint
study of NAEG Area 13 soils data on plutonium.
Estimates of average
239°240 concentrations in surface soil (0-5 cm) were obtained using
kriging technique.
These then were compared with NAEG observed plutonium
data, in order to calculate possible correction factors to provide even
more accurate plutonium inventory estimates than are presently available.
The necessity for careful planning of field sampling studies in order
for kriging or any statistical technique to give reasonable estimates of
inventory and spatial distribution of plutonium and other radionuclides
is also discussed.
Gilbert and Eberhardt, PNL, presented a summary of PNL's statistical
design and analysis activities for the NAEG since 1971 and a report on
the current status of their work.
A list of references is included on
statistical topics of interest to environmental studies planning groups
such as the NAEG.
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