HISTORICAL REVIEW OF TRANSURANIC ANALYTICAL METHODOLOGY
Robert A. Wessman and Leon Leventhal
LFE Environmental Analysis Laboratories
Richmond, California
ABSTRACT
The methods used for the analysis of the transuranic elements neptunium,
plutonium, americium, and curium are reviewed.
Particular attention is given
to those procedures suitable for low-level environmental and biological assess-—
ment.
The preparation of such samples, derived from a variety of sources and
incorporated in different masses and volumes of soils, water, vegetation, and
biological matrices, is described.
A comprehensive discussion of matrix
dissolution and equilibration techniques indicates that complete dissolution
employing tracer techniques is to be preferred.
Leaching of large soil samples
is satisfactory for worldwide fallout.
Individual and sequential separation
and purification procedures, including precipitation, extraction, and ion
exchange methods, are described.
Sample preparation techniques for radiometric
assay, such as stippling, evaporation, and plating, are reviewed.
For both
tracer and nuclide assay, electroplating provides the thin samples suitable
for alpha pulse height analysis.
Past and current counting methods for the
transuranic alpha, beta, and gamma emitters are reviewed.
INTRODUCTION
Current interest in the transuranics (TU), particularly Np, Pu, Am, and Cm,
stems from problems of potential or actual dissemination in the environment of
reactor waste, fallout, and the progress on development of the breeder reactor.
It also stems from such studies as the assessment of these elements at Enewetak
and Bikini, studies of plutonium sites by the Nevada Applied Ecology Group,
and a variety of plant and animal uptake studies.
Recently, 24!Am, because of
its growth from 2*!pu, has become a factor in the environment and interest in
this isotope increased.
Neptunium and curium as well as Am are expected to
accumulate in radioactive waste from reprocessing plants and are also of
interest.
Although the history of the transuranic elements began a short time ago, with
the advent of the nuclear age, the analytical methods employed to separate and
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