area _— wow am HEADQUARTERS TASK GROUP 7.1 AGO at JOINT TASK FORCE SEVEN £6 Los a ALAMOS SCIENTIFIC LABORATORY J Division. P.O.Box 1663 | Los Alamos. New Mexico 29 July 1954 Gordon M. Dunning Biophysics Branch Division of Biology and Medicine U. S. Atomic mergy Commission s a . * Tal. Washington 25, D.C. Dear Gordon: A * s CONFIRMED TO BE UNCLASSIFIED aY AUTHORITY OF DOELOC c Hf 1 ff- (- 34 a sate by: Dick KooChLe 9-19-87 Thank you for your complimentary letter. The maintenance of records at an operation leaves much to be desired and it entails the largest work load of the unit. We have been studying methods to improve present dosimetry practices and hope that by experience we can improve and simplify the system presently used at the Nevada and Pacific Proving Grounds. Two conspicuous deficiencies were noted during the operation: a. ina widely dispersed operation, control mst be exerted through the use of self-reading pocket dosimeters -- but these dosimeters should reflect film badge dosage, should be operative in areas of high moisture and under rugged usage, and should be easily maintained and repaired. At Castle we were hindered by cheap and unreliable pocket dosimeters as well as high loss rates. b. High contamination conditions, dispersal of activities aboard scattered ships, and the processing and recording of film badges under fluid ccnditions is too slow for adequate control of personnel exposures when there is lack of a coordinated, planned program of activities within a radiologically contaminated area, A number of exposures between 4 and 5 reentgens were the result of late film recordings "catching up" with a worker who had ccntinued to work in a contaminated area without respite. We felt that a limit of 3.0 roentgens would have provided a buffer that would have materially reduced the number of overexposures. An analysis of exposures reveals 23 exposures in excess of 12 roentgens. The 3 exposures of Task Group 7.1 were military personnel of a DOD project who were assessed readings on the basis of one film badge left in a tent on Rongerik Atoll during a period of radioactive fall-out. Actual exposure is believed to be 40 - 45 roentgens,. Three TG 7.3 boat operators returned film badges reading 85, 95 and 96 roentgens. Our investigation indicated their activities did not substantiate these high exposures and left their actual exposure subject to question, Ty DOSARCHIVES