UNIQUE DOCUMENT #55 \ & pl LCP EM, OL TFA IN REPLY REFER U. S. NAVAL RADIOLOGICAL DEFENSE LABORATORY toris: SAN FRANCISCO 24, CALIFORNIA 3~901-258 EPC: icm | Va AC AOS 15 MAR is-- Dr. Gordon M. Dunning, Health Physicist Biophysics Branch Division of Biology and Medicines Atomic Energy Commission Washington 25, D. C. STi RET i y At BEST COPY AVAILABLE This is a wery late response indeed to a letter that you wrote on September 9, 1955, asking for comments on the points you discussed relative to my letter of August 23rd in connection with the beta-gamma problem. On the assumption that a response may still of some historical interest, I should like to mention the following: & OU! DECLASSI AGYae ee 4 - Dear Dr. Dunning: DEPARTMENT Of | iow 3. 218 a. It was not our intent to criticise the actual value ef 100 to 1 beta-gamma ratio which appeared in your paper. We were merely |{ attempting to point out that there might be some ramifications which needed explanation or discussion, and for this we suggested reference material such as USNRDL Technical Memoranda 218 and 24. SS b. As far as the variation of the beta-gamma retio with time 23 23% is eoncerned, I would suggest that you refer to a paper by Mr. C. Sonibaus of this Laboratory, namely, USNRDL-394(1952). This paper rresents (for fission products) a plot of a calculated beta-gamma ratio versus time and also on the same graph shows effective gamma and beta energy curve as a function of time. ce. The deviations from the g7t-2 decay law have been obtained in field operations - See, for example, Project 2.6a: Operation CASTLE ISTS Fiml Report, Wr-917. non-fission product activities for the CASTLE Bravo type contaminant. 2, 5 . : e. The experimental work on the penetration of radioactive particles into clothing has not been done at this Laboratory. We would appreciate any reference you might give us on this subject. ef, A a. kx > \ \ 8 ~ ‘4 0 c0 A 2. We have not seen any definitive results on the amount of As was also in my letter of August 23rd, the above comments were pri- marily formujated by Drs. J. D. Teresi and A. Breido. “th s do ment consists of 5 8 A Tri3 is opy / of 2 pages. — =. G6..46 Sincerely yours, fo EUGENE Associate Scientific Director Gok bo eae HATH 8SHES 2 — 4 sr om, verse Tee STR 7 Tepe a ae oe fi