eific Events
Fall 1961 - There was a relatively large rise of I-131 in
milk in the mid-west in the fall of 1961.
(See Table II.) This
probably resulted from the U.S.S.R. shots on September 10, 1961.2"
The ensuing trajectory was unique <- curling around the North Pole,
passing down the U. S. eastern coast, turning westward along the
Gulf coast states and hence up the mid-west.
The fallout was
principally in the form of dry deposition fram the cold polar air
mass (as contrasted with the more usual method of "rainout").
Spring 1962 - There was also a relatively large rise of I-131
levels in milk in thé mid-west in the spring of 1962.
Table 111.)
(See
This could have resulted from the U. S. tests at
Christmas Island.
There were severe thunderstorms over the mid-
west, reachihg into the lower stratosphere he
Salt Lake City and Environs July 1962 - There were relatively
large rises in the I-131 in milk at Salt Lake City and its
environs?’ due principally to Small Boy (July 14, 1962) and to a
lesker extend by Johnie Boy (July 11, 1962) and Sedan (July 6, 1962).
(See Table IV.)
The peak value for any semple was 9,000 micro-
microcuries per liter (a grab sample fram a herd near Salt Lake
City; not a composite sample).
os
DOE ARCHIVES
Des Moines Event - On June 13, 1962, Des Moines underground
shot released a substantial amount of radioactive debris; i.e.,
considerably greater amount than if it had just vented.
The tra-
jectory was northerly for a few hundred miles, then toward the
3