SF ee
of intensity with altitude had been studied and that he
believed good delineation of fallout had been made.
He added
that a cloud model had been established which would allow more
precision in predicting areas of local fallout,
although it
would not be possible to predict hot spots too well because
of variation in wind.
Also, existing methods were suitable for
predicting variations in the size of contour areas between
thermonuclear weapons with a high percentage of fission yleld
and those with a low percentage of fission yield,
Mr. Libby requested that he be provided a copy of the
report on the radiation effects program.
He also inquired
whether the project had studied strontium-90 fallout as well as
fallout yielding gamma radiation and Colonel Maxwell replied that
no Gata had teen received cn strentium-9C fallout.
Mr.-Libby also
asked Colonel Maxwell to inform him of any studies which had been!
made of the tons of material taken up by a shallow water
shot as opposed to a deep water shot.
Mr, Libby said that when data on the program were more
complete, he believed it would be desirable to arrange
another briefing.
Dr. Dunham commented briefly on the world-wide radiation
fallout monitoring program which had been undertaken in con-
junctien with Operation REDWING and said that complete data
would not be received for a few weeks,
However, with regard
to intermediate tropospheric fallout, he said that no reading
above 10 times the background radiation level had been observed
in the U.S, until August and it was believed that these readings