# sfactory for Micld RadLaboratory, or in the fiLeld arospecting, but they are unsati Safe work utilising military personnel. This was clcarly brought out on several in measuring radiaticn on 3 occasions when oxpericnced military moniters, trained cted radiation intensitics loboratory scale, became unduly alarmed at observing unexpe of a fow tens of milli-roentgens after "DOG" and UT TEN shots. ALthoush the inbensi- tic health hazard, ties observed were far below levels capable of producing a realis ive that they these monitors became alarmod because their instruments were so sensit showed large readings. As a result of these reports at the tinc, some military eche- lons scomod to be alarmed. It is belicved that further training in similar exercises in orfor military personnel sheuld be carried ons with Less sensitive instruments der to obtain a more realistic approach te permissible desagus, 2. PReLIMINARY OPERATIONS Prior to the first shot, personnel of all task groups were trained in the us Radsife pers- of radiac (Radiation Detection Indication And Computation) cquipment. onneol assisned to the Scientific Jask Group became acquainted with the personnel and with the special probloms of the group. © 3, "DOG SHOT te Ab tho Commander's weathuy bricfings for the "DOC" shot rchoarsal, and for "DOG" shot, a three dimensional device was used to display the forecast of upper air winds over zero point. The winds were related to fall-out as a function of drift of all portions of the atcmic cloud from ground to maximum height which the cloud was expected to reach, in addition to this use of the wind directions and velocities, ar attempt was made to relate general atmosphcric stability ond precipitation probabiliby to fayorable or unfavorable fell-out consbideraticns, b, ‘the presentation anc discussion resulted in « forccast SURFACE RADEX (Radiological Exe Lusiion areca). This was disseminated by tho commander, Jeint Task Foreo THREE to all the task groups and was valid for one (1) hour ufter detonation, If fall-out proceeded according to the forccast, the RADRX could then be cancolled at H plus 1 hour and normal operations would then be resumed. Usual RADSAFE pro- cautions would be taken theroafter for lagoon braffic. c, It was planned that actual clearance to enter islands of the Atoll would be the result of a detailed, but rapid, island survey by low flying Sircraft. Rad~ Safe clearances for individual uninhabited islands would be granted at about H plus 3 hours, «All essential work on shot islands would go forward because seasoned Rad- vafo monitors were provided for all such essential working partics, These monitors a . Loos . tet ae . were especially trained and, with their cxpericnce and professionel qualifications, pee were capable of "on the spot! ovaluation, ~e= SO LR vy 3h i A