AIR SAMPLING DURING TIME OF PACIFIC TESTS (1956)
D.R. Atherton
Pursuant to the request of Gordon Dunning, this laboratory participated
in an air monitoring program during the months of April through August 1956.
With an air sampling device having a filter paper area of 63 square
inches,
107 daily samples were taken.
intake 20 ft.
Lake City.
analysis
above ground level
This device was located by an air
in a 5-story building 1 mile east of Salt
The samples along with pertinent data were forwarded for further
to Mr.
Joe
B.
Sanders,
Chief,
Las
Vegas
Branch
USAEC,
Las
Vegas,
Nevada.
Prior to sending the samples away, a circular area one inch in diameter
was counted with a G. M. tube.
Most of the filter papers were counted within
a day or two after sampling.
The counting efficiency of this G. M. tube
varied
beta
from about
5%
for weak
energetic beta emiters such as yo.
this
0,785 square
inch
area
to
emiters
such
as
ca? to about
15%
for
The ratios of net beta counting rates on
instrument
background were
calculated
and
normalized to 1,000 ft? of air passing through the air sampling device.
Background was about 20 counts per minute.
The distribution of the normalized
net beta counts to background counts was as follows:
PERCENT OF SAMPLES
NET /BACKGROUND
54
31
5
10
0
2
5
7
-->
-->
-->
-->
1.9
4,9
6,9
14,2
The values from 7 --> 14.2 occurred for samples collected on the following
dates:
April
17-18;
19-20; 23-24; 24-25; May 10-11;
15-16; 23-24; 31l-June 1;
June 12-13; August 2-3.
Post script (1959) - Air samples were also taken during the spring and summer
of 1957,
directly
These filter papers were not counted in Salt Lake, but forwarded
to
Dr.
Oliver B.
Placak,
Off-Site Rad.
Safe Office,
Organization, USAEC, P.O. Box 2088, Las Vegas, Nevada.
-1-
Nevada Test