Sen!
Dr. J. H. Harley and Mr, I. B. Whitney
.
July 2, 1956
Eduard P. Hardy and Seymour Tarras, Chemists
410875
Analytical Branch, Health and Safety Laboratory
GENERAL MILLS HIGH ALTITUDE BALLOON FILTER SAMPLES
NON-CCRKP
SYiBOL:
HSAsEPR:ST
Ten (10) filter samiles forwarded to HASL by Dr. Worf have been
analyzed for total beta activity, Sr-89, Sr-90 and Cs-137. Per~
tinent information available and analytical results are reported
4n the accorpanying four (k) tables, General Mills sarples nuz-
LLLST§/
DATE
DATE 3 -/S—57
COUo-S
a
Rach filter was ignited at 550°C for twelve (12) hours end ths
residue transferred to a gless planchet and beta counted. K-)0
was used es a standard.
The standard cubie foot values rere
obtained fron Dr. L. Machta by phones.
—~
At that tina it wes ex~-
plained that these figures were based on calculation of fan
revolution rate which was not constant throughout the eazpling
period. The efficiency for collection of particles at these
altitades is considered to be 25% but the data presented in this
memorandum hes not been corrected for efficiency. No blenk filters were received for control analysis.
SY AUTHORITY OF
CLASSI ICATION CA
NCELLED
YC es',
bered Bf k and 5 were reported lost.
,
In reference to the ensuing comments, possible variation of
nuclide abundance or other paramster with tine hes been disre-
garded.
There is no apparent correlation of ash weight with
altitude. By plotting isotcpic concentration in d/a per stan~
dard cubie foot with altitude (Figures I-IV), 4t appears as
though total beta activity diminishes with increasing altitude,
A range of 0,96 to 1.1) d/a/std ft3 is indicated for the saxples
collected between 58 and 60 thousand fcet and a range 0.16 to
0.38 for those collected between 76 and 92 thousand feet.
Like~
wise, the concentration of Sr-90 end S&r-59 seems to decrease with
The concentration of Sr-90 falls within the linita
10.036 and 0.05 d/a/sta £t3 between 58 to 60 thousand feet and
Ehvithin 0.010 and 0,032 between 76 to 92 thousand feet.
Ly plot~
ating the relative meclide abundance in per cent against éltitude
Fugures Y-VII), there 4s indication of an enrichment of Sr-90
Y
Lo Uva
Box
CollectionDBM Giles
US DOE ARCHIVES
326 US ATOMIC ENERGY
COMMISSION
RG
increcsing altitude, while this trend is not evident in the casa
“of Cs-137.
arkcdiVes
BEST COPY AVAILABLE
vi