ji szamonysoc } ae qu Proposed Release of Information on Strontium-90 Production from weapon Testing Report to the General Manager by the Director of the Division of Classification The Problem 1. No. To consider the declassification of the fact that U. S. nuclear weapon test series and the Hiroshima and Nagaski bombs resulted in the release of certain quantities of Sr-90, specifically the data presented in table 1 of Appendix A. - aa Summary and Discussion a 2. Presently, attempts to assess the radioactive fallout hezards from Sr-90 of continued’ testing of nuclear weapons must rely heavily on extrapolations of measurements of contamination levels (Project Sunshine data) resulting from nuclear weapons tested. wot Absence of specific information regarding actual production of strontium in nuclear weapon tests has been a major weakness in such extrapolations. However, an assumption of a oot uniform testing rate of LO megatons of fission yield per year over the | past five years has been used which approximates the total fission yield in all U. S. devices detonated thru Redwing. The table in the attached report (Appendix A)"presents the total Sr-90 activity produced by each oe United States nuclear weapon operation through the year 1956 (Operation Redwing). These totals are sub-divided into two groups, namely: (1) be. the total Sr-90 activity produced by weapons with total energy yield of less than 1 megaton and (2) the total Sr-90 activity produced by weapons with total energy yield of more than 1 megaton. This division is important major contribution to world-wide fallout. The publi hazards rom restricted Nata as defined . | ah Keith gr = AN EES BR Pe is as much as only the weapons with yields of 1 megaton or greater make a