MEASUREMENTS OF AIRBORNE RADIONUCLIDES
AND DETERMINATION OF THEIR
PHYSICAL CHARACTERISTICS
R, W. PERKINS, C. W. THOMAS, and J. M. NIELSEN
Hanford Laboratories, General Electric Company, Richland, Washington
ABSTRACT
Newly developed counting techniques that employ multidimensional
gamma-ray spectrometry have been employed for the direct measurement of a large group of radionuclides in fallout samples. These techniques have made it possible to study the distribution of many of the
trace constituents of fallout and also to improve the precision for the
measurement of the more abundant radionuclides. The concentrations
of ‘Be, ?Na, #Mn, C9, By 577—8Nb, 16Ru, 12 Sp 1255p HO B7Cg
and '4Ce can be measured directly. Their concentrations in air during
the past 2°), years are reported. The measured solubility of the fallout
radionuclides is reported, and their deposition as dry fallout and as
rainout in the area of Richland, Wash., is compared. The distribution
and movement of the tracer radionuclides "y and !4Sb and of 7°°Pu
both in the stratosphere and in the troposphere are discussed, The
cosmic-ray-produced radionuclides Cl and *8S are mentioned, and
their application along with other cosmic-ray-produced radionuclides
in atmospheric research is considered.
INTRODUCTION
The absolute and relative concentrations of the various airborne
radionuclides are of interest both in measuring their distribution and
deposition rates and in studying the physical and chemical processes
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