B. Monitoring of fallout from nuclear weapons tests:
During the past 3 years increasing responsibility for the monitoring of fallout has been
assumed by the Health and Safety Division of the AEC New York Operations Office, with aid
from the weapons test organization and from a numberof federal agencies. A notable feature
of the current program is a network of approximately one hundred domestic and half as many
foreign stations at which fallout is collected by permitting it to fall on a horizontal gummed
paper or plastic sheet. The sheet is held in a frame supported by a light metal stand, two feet
in height, and has an exposed surface of one square foot. At appropriate intervals the sheet
is removed, folded in half with the gummedsurface inside, and sent to NYOO for measurement
of activity.
Some of these stations are operated continuously between series of tests.
a
.
At the Nevada test site, off-site monitoring within distances of one or two hundred miles
has frequently been carried out by mobile teams spotted downwind. Conventional aircraft and
helicopters have been used to a very limited extent. On-site monitoring has been performed by
local radiation control groups. Fallout in these locations is generally estimated from radiation
levels. Since the personnel involved in these monitoring operations have been primarily interested in problems of personnel protection rather than in applications to GABRIEL, data on
short-range fallout have been very incomplete.
At the Pacific Proving Grounds, monitoring of local fallout—in this case, within distances
of a few hundred miles—has been generally inadequate because of operational difficulties involved.
C. Distribution of Sr-90 from nuclear detonations:
In the summer of 1953 RAND held a short conference of selected consultants to make an
over-all review of GABRIEL. The conference recommended‘ that studies then current be
supplemented by a world-wide assay of the distribution of Sr—90 from the nuclear detonations
which have occurred. This assay has been designated Project SUNSHINE.
Samples for assay have included soil, alfalfa, animals, dairy products, human bones, rain
and other water, etc. Samples of one or more of these materials have been obtained from each
of some 20 foreign countries. Many of the samples have been obtained through the Department
of Agriculture and directly by the participating laboratories; others have been obtained through
miscellaneous contacts. Three laboratories have been engaged in analyses of samples for Sr—90:
University of Chicago (W. F. Libby) ; Columbia University (J. L. Kulp); and New York Operations
Office, AEC (Merril Hisenbud and John Harley).
A decision to keep the existence of a worldwide
assay SECRET has limited the freedom with which suitable combinations of samples might be
obtained from foreign countries.
D. Experimental studies:
Some estimates of the radiological hazards involved in the use of nuclear weapons have
been made on the basis of the considerations listed in Section II above. Our knowledge of some
of the factors involved is very meager, leading to large uncertainties. While direct observation
of the distribution of Sr-90 from nuclear detonations reduces some of these uncertainties,
application to prediction of the distributions which may result under other sets of conditions
requires knowledge of the effects of those factors which change from one set of conditions to
another. Of fundamental interest are soil-plant-animal-human relationships, utilization of
land, relative geographical locations, climate, etc. In addition to these, there are questions of
radiological effects of exposure to radiation—questions on which Project SUNSHINE sheds
no light.
Some evaluation of the factors involved in extrapolation of observations on human exposure
to Sr-90 from past nuclear detonations to exposures to be anticipated from the use of nuclear
weapons in warfare is built into Project SUNSHINE. For example, samples of soil, plants and
2
Footnote references on pp. 42-43.
VA.
DOSARCHIVES