WORLDWIDE EFFECTS OF ATOMIC WEAPONS

At the conclusion of a conference on the long-term effects of atomic
weapons, held at The RAND Corporation, Santa Monica, California, in
1953, a classified report, R-251-AEC, was prepared. Along the lines suggested by this conference a concerted effort, under the name of Project
SUNSHINE, developed to evaluate the long-term effects. Since R-251-AEC
has formed the basis of many subsequent studies, it was felt desirable to
issue an unclassified version of this report. As presented here, the report
has some deletions and changes, but differs little from the original 1953
version.
This report should be read in the context of the state of knowledge of
the SUNSHINE problem as it existed in 1953. It is presented as an historical
document.
The changes in some of the physical constants should be particularly
noted. When the calculations in Chapter 5 and other sections of the report
were made, it was believed that the half-life of strontium 90 (Sr”) was
19.9 years. A more recent and better value seems to be 27.7 years.*
1
This value combined with a new value for the fission yield of Sr gives
the basic result that approximately two megatons of fission will produce
millicurie (mc) of Sr/mi², if the fission products are uniformly distributed over the earth’s surface.* This should be contrasted with the early
(1953) correspondence of one megaton resulting in 1 mc of Sr/mi².
To preserve the perspective of this report, the original data stand uncorrected. It is a simple matter for the reader to apply the corrections
regarding half-life and fission yield should he so desire. It should be noted
that the effect of a greater half-life and a smaller fission yield will be to
D. M. Wiles and R. H. Tomlinson, “Half-Life of Strontium 90,” Can. J. Phys., Vol. 33, 1955, pp. 133-137. +W. F. Libby, “Radioactive Strontium Fallout,” Proc. Nat. Acad. Sci., Vol. 42, June, 1956, pp. 365-390. iv WORLDWIDE EFFECTS OF ATOMIC WEAPONS increase the megaton “limits” (i.e., decrease the apparent hazard) as calculated herein. On the other hand, certain natural factors and concepts regarding the mechanism of the Sr path into the human body have also been revised. For example, the original assumption regarding the amount of available natural strontium in the soil is evidently too high; the effect of lowering this value is to decrease the megaton “limits.” In fact, the SUNSHINE “limit,” as recently estimated by W. F. Libby, is lower than that given in
this report. It is emphasized that absolute values, both biological and
physical, given in this report must stand corrected in the light of investigations conducted since 1953.
Several of the speculative aspects of the report were recorded without
the advantage of the data that have accumulated since the inception of the
SUNSHINE experimental program. Some of the conclusions have withstood
the test of time; others undoubtedly require modification on the basis of
the SUNSHINE experience of the past 3 years.