PRIVACY ACT MATERIAL REMOVED ’ The phenomenon of radioactive-fallout from an atomic explosion is described, anda .. quantitative technique for determining the distribution of radioactive material on the ground is’developed. The primary factors which must be considered are windfield, yield and height of burst, and particle-size distribution. Certain parameters which enter directly into a fallout determination are given quantitatively, such as the altitude and size of the atomic cloud (as a function of explosion yield and atmospheric stability) and particle fallrates (as a functionof altitude and particle size). .Two hypothetical fallout patterns for a one-megation explosion, computed on a high-speed digital computer are presented, showing the large effect which the wind has in determining the character of the fallout. The meteorological problems associated with a fallout prediction are discussed. 31. Kimura, Kenjiro. ANALYSIS OF RADIOACTIVE FALLOUTOF THE ATOMIC BOMB EX- PLOSION ON BIKINI... Radioisotopes (Japan) 3, 1-4 (1954). ; The. radioactive fallout was found to contain 55 2,°7.0, 11. 8, and 26.0% of CaO, MgO, CO,, -and H,O, respectively, the chief-constituent being Ca(OH)s. The electric-spark method of analysis showed the presence of Al, Fe, and Si in addition to Ca and Mg. Its decay curve followed I = ct7!3", where I represents radioactivity, t, time since the explosion took place, March 1, 1954, and c, const. Its specific activity measured on April 23, 1954, was 0.37 mc/ g. Radioactive nuclei identified by March 26 were Sr®’, Sr®, y*!, sr%5, Ness | Nb*®, Rut03 Rh'S pett9m p|ei2pois? p18! 7132 Ral Celli Celt pri, pri nal? PmMr S35, Cal’, U2" and Pu2s9. ’ 32. Kimura, Kenjiro. INTRODUCTION TO SPECIAL COLLECTION OF PAPERS. ANALYSIS OF THE BIKINI ASH. Japan Analyst 3, 333-34 (1955). The incident of the Bikini ashes and the fishing boat is reported. Experiences on the boat are recorded, and fallout analyses are compared with those of Nagasaki and Hiroshima. 33. Kimura, Kenjiro, Ikeda, Nagao, Kimura, Kan, Kawanishi, H.. and Kimura, M. RADIOCHEMICAL ANALYSIS OF THE BODY OF THE LATE MR.. . Radioisotopes (Japan) 4, 22-7 (1956). _ Analyses were carried out of various organs of Mr. ° . 200 days after he had exposed himself to radiation of the atomic'bomb explosion on Bikini Atoll, March 1954. By ion-exchange chromatography, the presence of the following nuclides was indicated: Ce and Pr’4 in the bone(I) (20 x 107? counts/g. fresh wt.). Liver (II), and Kidneys (II); zr® and Nb®* in I. and WI; Ru’*, Rn6 Te!2?Mang Te!?* in I, II, and muscles; and Sr®*, Sr*°, and y” in I, 0, and OI. Activities found in these organs were decidedly higher than those found in the control samples obtained from individuals who died of other than the so-called radiation sickness, Radiation dose received by the bones of Mr. was calculated to be approximately 8 rep. 34. Kulp, J. Laurence, Eckelmann, Walter R., and Schulert, Arthur R. MAN, Science 125, 219-225 (February 8, 1957). STRONTIUM-90 IN The world-wide average strontium-90 content of man was about 0.12 micromicrocurie per gram of calcium (/10,000 of the maximum permissible concentration) in the fall of 1955. A few values as high as 10 times the average have been obtained. This valve is in accord with the predicted value based on fallout measurements and fractionation through the soil-plant-milk-human chain. With the present burden of strontium-90, this average level should rise to 1 or 2 micromicrocuries of strontium-90 per gram of calcium. 35. Langham, Wright H., and Anderson, Ernest C. MATION. Science 126, 205-06 (1957). STRONTIUM-90 AND SKELETAL FOR- « 36. Lapp, Ralph. INTERVIEW BY MIKE WALLACE. ABC Television Network, Sunday, June 9, 1957. 15p. 37. Lapp, Ralph. STRONTIUM LIMITS IN PEACE AND WAR. Bulletin of the Atomic Scientists 12, No. 8, 287-9 and 320 (1956).” 38. Lapp, Ralph, Kulp, J. L., Eckelmann, W.R., and Schulert, A. R. Science 125, 993-34 (1957). STRONTIUM-90 IN MAN. Biological hazards from fallout Sr*®following nuclear explosions are discussed. - 161 : PRIVACY ACT MATERIAL REMOVED ‘ 1 he