Ciibalses sty) ( ¥ErI ACE . an oy 2 “¥ HEADQUARTERS TASK GROUP 7.1 JOINT TASK FORCE SEVEN Los ALAMOS J ScIENTIFIC Division, P.O.Box Alamos. Los 410448 LABORATORY 1668 New Mexico 29 July 1954 Gordon M. Dunning Biophysics Branch Division of Biology and Medicine U. S. Atomic mergy Commission washington 25, , _. _US DOE ARCHIVES 326US ATOMIC EXERGY RG COXLESION DIVISIG if OF BiCLOGY & MEDICINE Collection D. C. , 3366 Box . Dear Gordon: PoldcrM@4S 3-8 Mamtinoe + FarcoytT Thank you for your complimentary letUen.The msintenence of records at JY an operation leaves much to be desired and it entails the lergest work load of the unit. We have been studying methcds to improve present dosinetry practices and hope that by experience we can improve and simplify the system presently used at the Nevada and Pacific Preving Grounds, Two conspicuous deficiencies were noted during the operetion: a. Ina widely dispersed operation, cortrol rust be exerted through the use of self-reading pocket dosineters -- but these dosimeters should reflect film badge dusage, should be operstive in areas of high moisture and under ruused usage, and should be easily; ~ainteined and reraired. At Castle we were hindered by creap and unreliable pocket dosimeters as well as hign loss rates, {Js wvi of a. ct ct ~ g) a ct! { Ae rr % ct = na oO aan ct fe t aa Fy 1-6 OQ "3 mm Ott Ry DATE Co REVIEWED BY A ft £ LZbse BY AUTHORITY OF poe! oc. CONFIRMED TO Rf LINCLASSIFIED I-y FR b. igh cortarination conditions, dispersal c ies aboard avtered Sete ss ane ue processing @ asd recording o ses under ve exposures 00 Slow for adequate curtrel o there” is “lack: of a coordirated, plenned prograx iclociczily ccntaninated area, Armuber of exposures Lstweer 4 and rigems were the result of late film recordings "catching up" with a & continued to work in a ccntaninated area without respite. it viet 42 linat of 3.0 roentgens would rave previded 6 buifer that teriallvy reduced the murver cl overexrcsures, nanelysis cf exposures reveals 23 exposures in encess of ler he 3 exposures cf Task Group 7.1 were military jerscennel of a wio were assessed readings on the basis of cne film badge left i or norgerik Atoll curing 2 period oF radioactive set is believed tc be 40 - 45 roentzsens. Three TG 7.2 boat operators returied film beczes reading $5, 95 and 9 roentsens. Cur investigation indicated their activities dic net substantiate these hich exposures and left their ectuel exnosure subject to question. d om . : : - 4 * > - ae BEST COPY AVAILABLE an Z