— 189 Se LawrenceLivermore National Laboratory TO: All holders of UCRL-53152, "Results of Calculations of External Gamma Radiation Exposure Rates from Fallout and the Related Radionuclide Compositions," Part 3, "Operation Tumbler-Snapper, 1952" FROM: Technical Information Department ADDENDUM For purposes of clarification, the following information (underlined below) is being added to your copy of UCRL-53152 Part 3: Each Appendix contains 11 pages of calculated results relating to one Event in Table 1. Each set of 11 pages is marked Page 2 through Page 12 at the top and A2 through Al2 (or B2 through B12, etc.) at the bottom. Page 2 of each set gives the external gamma-ray exposure rates and associated values of total microcuries per square meter at 30 decay intervals and at zero time. Note that the totals at zero time include only the nuclides listed in pages 3 through 12, not all the nuclides present at zero time. Calculated values for each radionuclide at various decay intervals are given in the remaining pages--from 1 to 21 hr in Pages 3-7, from 1 to 300 d in Pages 8-11, and from 1 to 50 y in Page 12. Unless otherwise indicated, the value for each nuclide at zero time is the result of a radiochemical measurement. The measurements were performed on debris samples taken by aircraft approximately 1 to 4 hr after detonation. estimated. The production of nuclides designated by (*) has been’ When no estimate could be made, the value appears as zero. To incorporate this addendum, please staple or affix the attached page so as to cover the existing Page 2 in your document. cal Information An Equal Opportunity Empiover « University of Caliornia * P.O, Box 808 Livermore. Califorma 94550 * Telephone (415) 422-1100 * Twx 910-386-8339 UCLLL LVMR ee