Wile 8) srk
stad
r
*
pantee od Salaun se
elke oh
at aah
ae omee
'
a
ABSTRACT
A5" x 3" NaI(T1) detector and a high pressure ionization
chamber have been used to obtain gamma ray spectra and total
gamma dose rates at approximately 100 locations during the
course of several survey trips in the southeastern,
and western United States.
central,
Reasonably precise estimates of the dose rates from each
of the individual components of both the natural and fallout
gamma fields are made using the pulse height spectra and rela-
tively simple methods of analysis.
The equipment and types of
locations surveyed are discussed briefly and the methods used
for determining component and total dose rates from the pulse
height spectra are summarized.
The total terrestrial dose rates as well as the partial
dose rates from the uranium-238 series, thorium-232 series,
potassium-40, zirconium-niobium-95, and rhodium-106 are tabulated for each location.
Particular results of interest with
respect to environmental gamma radiation,effects of precipitation on fallout gamma dose rates, and the validity of the
spectral analysis methods are discussed.
Among these results
are the relatively high natural dose rate levels in the Denver,
Colorado area and the correlation between fallout gamma dose
rates and mean annual rainfall for several sites on the Olympic
Peninsula, Washington.