To Col Stafford Warren Chief Radiological Safety Section Operation Crossroads 140671 Submitted by IT' ' A ' ' _ r n I Jo • • ' • • al ' PRlVACY ACT MATERIAL REMOVED • ·- • Obaerrationa aJld $ugge•tiona Resulting from Participation in eat Able and Teat Balcer A Civilian Atomic Bomb Monitoring Corps I was awe re that the monitors were probabl 1' chosen because thq were physicisna or scientists uperiencecl in radiation or radiolog or both as well as that they were selected from wideq scattered communities throughout the country It seemed to • that the training we received and the first-hand experi nce we gained with phaaollml associated with atomic bomb uploaiona would be beat exploited and moat usefttl to our nation 1n time of the 1 ueTitable atomic bombiJl4ga of our citiea if we were organized into a nation-wide corps of monitors instantaneoual 1' available for service during and following such e ttaclcs We could have a civilian status such as that of ilr-Raid Wardens and mambera of the Civilian Defense Corps during World War II We should be provided with suitable ident ll insignia end credentials to enable us to perform our duties as expeditiouely as possible A travel and comD11111ication priority for such emergenCJ' use shou1d be assigned us so that we could contact a centra1 headquartera immediately at any time and be directed to travel to those cities or ares a in our own communities which had greatest need for monitoring We should have in our possession at all times several recentl1' tested instruments see below both for replacemea t and for daputiea trainecl on-the-spot for their use under our direction We should also have several hundred signs marked Dangerous B adioactirlt7 Do Not Stq Here 0 - r with the blank to be filled in by the monitor in minutes or hours with black w cr q On The experience we gained at Bikini should be considered as our ini tip l training period We should be assembled at a source of large amoUllts of redioactivit7 such as a pile periodically every two or three years for refreeher purposes and to acquaint us with the proper use of the latest instruments trupplied us as they evolve Since severa1 scores of German scientists were captured by a potential eneJ 7 and are undoubtedly now being exploited by that nation for the development of methods -2- of production of atomic bombs we anticipate that an atomic bomb attack on our cities Illa7 be launched at a ny time swiftly and without warning probably by rockets or by placements by saboteurs Therefore the proposed Civilian Atomic Bomb Monitoring Corps should be organized and probably expanded as soon as possible Those monitors who served in Operation Cro saroads might serve as the nucleus of such a corps A large number of new monitors sho'-lld be trained at Test Charley to be added to the first group A large supplemental7 list might be recruited from those qualified by utensive monitoring experience on the Manhattan District B P-T Boat Re•cae and Monitori Dg Unit• • I was stationed aboard PGM 24 for ' eat Able and abca'd PGM 32 tor ' eat Baker A a 7011 know all of the gan-boe te became bad ¥ con taJllinated with radioactiTit7 after Teat Baker which limited their useful nee• somewhat in that the cren had to be eTacua ted at night because the excesab• radioact iTi t7 could not be disaipated b r ra nning the ships at sea MoreoTer these vet ll l•la have a minimma speed of a bout e t knot• which is too great for probing into sha rpl 7 delineated areas of highl T radioactive water BUch as we encountered ThirdJ T fair ¥ large crewe are required them On the other hand the LCP L ' a became liabilitiee when their- motor failed and they were likely to drift into high radioactivit y Therefore I should like to SU geat that in time of war for purpose• of rescu e of aa lvagable crews of ships on the fringes of atom-bombings for morale if' nothi ng more as well as monitoring functions that a boat intermediate in size be provided Probably a P-T boat or a modification of it would serve the purpose Such a craj't should have the approximate specifications a Two completely independent enginea 1erews etc l Be as large aJI possible sea-worth y but still small enough that 1t could be hoisted out of the water end the pd int contami Dated durillg the daT could be remoTed resiil r aJld a new coat of speciall1 deai D ed pcUnt be applied during the night in readiness for next da r 1 s activities c Be speed7 and verr mawnrverable so that rescues could be affected in a short time in waters that would be too 1 hot 1 to operate in with slower boats C Instrc menta As you are well awal e the multiplicity of instruments served o to confuse us Howe-rer their immber and va riet y was a good thing since it enabled a critical evaluation of performance in the field to be made It is of course essential that three sepe ra te instruments be ava ila ble for the performance of a satisfactorr monitoring job -3- 1 A rate meter in r per day 2 A CUilllllative dose meter 3 Film badges optional Apparently the film badges we used were satisfactor r insofar as gamma radiation was concerned although I have no basis for judging their efficacy- See D below for comments concerning beta radiation I thought the pocket electroscope type dosimeters supplied us were quite satisfacto17 he Proteximeter was worthleaa The confusion nearl 7 all laT with the various types of rate meters veJ 7 W1aatiafacto17 for the following ree sona a It too often failed to function entirel T liea rl T every'One finail1' tried to get hold of three or four of them to assure himself that at least one would be working by the time he had reached hia assigned poet b It did not read directl 7 in •r• per day e It becaJ1e V9 rJ' erratic and was often misleading on the 20X sea le when it waa eaeen tial that it function well d It did not measure high enough radiation int91lsitie• On the credit side the X-263 was a Light and ea q to carry b Ve17 sensitive more so than neceaaarJ c The head-phone feature was a good one The X-263 was For monitoring after atomic bombings of our cities it will be necessa r r that a fool-proof rate meter be available that will· emboq all at least of the following 1 It must mea111re ' IP to 200 11 r 11 per 2 It must have a thin enough window that f airl y low en erg beta r87a will be mes au red along with the gaJDDl rB1'•• This is an absolute 1 muat 1 • See D below 3 At rates above l per hour a safety we ming bell or buzzer should solllld contin aouaq 4 he lower limit of sensitivity- would not need to be lesa than about O Ol •r• per day 5 The dial should have a lighting device bahizld it for readlll •r• 6 7 in the dark Bew batteri•• easily installahle It must be sturd 7 alld gb up to four or five times that of the X-263 i f carried in the hand or more i f designed to be stra pped on the be ck In order to have the range indicated above the meter IIll st have several scales which must operate from the same zero setting with eas r switching between eca les There is good agreement among ph ysicists experienced in measuring radiation intensities that an ionization chamber is much more reliable than a counter device especially when portability is desired 0 o o v 'Q'4 J Q ' fJ iv -5- The contamination of u r r clothes and the screen the mesk of which only occupied a bout one-third of the total area led me to believe that much air-borne probably as aerosols beta-emitting material was spread around by the Baker bomb Aside from injuries to the skin and underlying structures from contamination of the clothes and hair I would be concerned with that which entered the lungs since a man at rest on the ships would have breathed in about 4oo-500 liters of the contaminated air per hour I do not believe that the film badge values for beta plus gamma compared with gaJIIJEla a lone had much significaJlce beca use the sensitive film was encased in thiclc paper plus a metal foil that would have stopped completely much soft beta radiation which however couJ d still have been sufficiently energetic to injure the thin aJld delicate luw structures I am not an alarmist Colonel Warren 8lld I aJl1 fully cognizant that hind-sight is mu ch better than fore-sight It is rrq opinion that probably no permanent rad iation injurJ' was sustained by aJlT of the participaJlts I do believe tho ugh that many of us probably received ma ch more penetrating ionizing radiation thsi the instruments of very low beta-eensitivity were able to record I have included this section principally because of us were very apprehensive and because I believe that air-borne beta radiation stabilized by the dusts of our a tom bombed cities may be several times more dangerous than the attendant gamma radiation Practical application of this opinion in prepar tion for such eventualities would be to design the instruments provided the Civilian Atomic Bomb Monitoring Corps proposed above or other monitoring agenc v so that both the rate meter and cwimlative dose meter reoorded beta r diation iasofar as possible along with the gamma radiation E Pecul iP r Beker Dey Phenomenon There was observed a peculiar well delineated ha Ze over the target area by several of us a board PGK 32 as we approached the lagoon entraJtce a bout two hours after the Bakar bomb bu rat The f e ct that the halo-like effect remained very symmetrical throughout the four or five hours during which it graduall y decreased in size end faded in intensity would illilica ta that it may ha ve been associated with some sort of radiation Even when most intense it would have been difficult to record photographicall7 and success would probably- have resulted only i f the camera would have been directed paralled to and not more than a hundred feet or so above the surface of the lagoon Its approximate shape and relationship to the target area at about 1100 and 1430 is sketched below NJ Jy ' l- 0 I r 3