wee eB atl se
tet. «aun
Plutonium-239 Anomaly in the Troposphere
by H. L. Volchok,
(HASL)
P. W. Krey, (HASL)
During the period mid-1968 through mid-1969,
some unusual be-
havior of Pu-239 relative to Sr-90 has been observed in surface air.
For many months and at many surface air sampling stations in the North-
ern Hemisphere, the ratio Pu-239/Sr-90 exceeded all values in the stratosphere at comparable times.
discussed in this paper,
Although a number of possibilities are
this apparent enrichment of Pu-239 is not
readily explainable.
Most of the Pu~239 existing in the world came about by the inter-~
action of enormous neutron fluxes in atomic explosions with the U-238
present in
such devices
of the weapons.
(1,2)
or
from unfissioned Pu-239
from the
cores
Much smaller amounts may have been released to the
environment by a variety of accidents and incidents on the earth's
surface such as airplane crashes at Thule,
Spain
(3)
Greenland,
and Palomares,
or the recently publicized contamination in the neighborhood
of Rocky Flats,
Colorado
(4).
Sr-90 on the other hand has been re-
leased to the atmosphere mainly in nuclear explosions as a product of
the fission reaction.
Since the major production modes of these two
radionuclides are very different,
their. distribution in the stratos-
phere and surface air have been studied for some time.
-
“oe.
.
7.
~
-
fem
-
oe
sare
eart ren pt ge tt per ge ere >