World-Wide Fallout from Operation Castle (Deleted)

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WORLD-WIDE FALLOUT FROM OPERATION CASTLE This is an extract of NYO-4645, which DATA as of this date. Extract version prepared for: DEFENSE NUCLEAR AGENCY Approved for public release;

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BEFORE COMPLETING FORM WORLD-WIDE FALLOUT FROM OPERATION CASTLE United States Atomic Energy Commission May 17, 1955 Technical Information Service !3.NUMDEROF l ACES Oak Ridge, Tennessee Approved for public release; unlimited distribution. This report has had the classified informationremoved and has been republished in unclassified form for public release. This work was performed by Kaman Tempo under contract DNAoO1-83-C-0286with the close cooperation of the Classification Management Division of the Defense Nuclear Agency. i world-wide network of gummed film stations was established to monitor fallout ‘ollowing Operation Castle. Although meteorological data were poor, a general con- ~ection of tropospheric flow patterns with observed fallout was evident. There was a ;endency for debris to remain in tropical latitudes, with incursions into the ;emperate regions associated with meteorological disturbances of the predominantly :onal flow. As the season advanced, such incursions became more evident. Outside of he tropics, the southwestern United States received the greatest total fallout, about ive times that received in Japan.

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This report has had classified material removed ’in order to make the information available on an unclassified, open publication basis, to any interested parties. This effort to declassify this report has been accomplished specifically to support the Department of Defense Nuclear Test Personnel Review (NTPR) Program. The objective is to facilitate studies of the low levels of radiation received by some individuals during the atmospheric nuclear test program by making as much information as possible available to all interested parties. The material which has been deleted is all currently classified as Restricted Data or Formerly Restricted Data under the provision of the Atomic Energy Act of 1954, (as amended) or is National Security Information. This report has been reproduced directly from available copies of the original material. The locations from which material has been deleted is generally obvious by the spacings and “holes” in the text. Thus the context of the material deleted is identified to assist the reader in the determination of whether the deleted information is germane to his study. It is the belief of the individuals who have participated in preparing this report by deleting the classified material and of the Defense Nuclear Agency that the report accurately portrays the contents of the original and that the deleted material is of little or no significance to studies into the amounts or types of radiation received by any individuals during the atmospheric nuclear test program.

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3.2 Totals for Individual 3.3 Comparison With Total OF DAILY FALLOU. ..... The work rermrtedon here was ~erformd under th directionof was estiblislmdby the Healthand SafetyLaboratory,New York Many helpfulsuggestionswere receimd frcm colleagus h the perfozmedthe laboriousand pamlaulng plottingof data and preparation of the finishedmanuscript*

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MeteorologicalTrajectoriesfor Burst No. 2, Romeo .... 10 Total FalloutFrom CastleSeries as of July 1, Total Fulout From Castle Seriesaa of July 1, Maxixm Activityon SamplingDay at Individual

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gumnedfilm stationsuss established cal data were poor, a gener~l‘&xmectionof troposphericflow patternswith observedfalloutwss etident. There wag a terxlencyfor debris to remainin trmical latitules,uith incursionsinto th Statesreceivedthe greatest to~l fallout,about five times that estimatedto be about ~f t* tital fissionactitityproduced. The maximumfallouton any day at an indltidualstationin the It is concluiedthat tb probabilityof early falloutin inhbited regionswould be red=ed by holdingPaoifictest series in the winter months.

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&pooit&on of radloaotivedust redting from tlm detonatla. For to inoltdel mpreeentativeworld+%de networkof 122 stations dleowseed in pmwioua reports. 8* the Wtallatlon of emu ‘T ed gunned film stud for we in enowycktes coneisted mklng tho obeervathns eoqmmble to thoee of rainfallon a con70 slqlify the proceduresused in correctingfor deoay ld e@m of burst aeeigznumtwas ueed in those caeeswhere th burst to lmve 00W from the latest burst, lotixityeleenhereIn tlM world,

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reassignedto the appropriateburst. In the case of obsermtions in deterninethe burst responsiblefor tb actitityfroman examination of t.% trajectoriesof the debrisin con$mction with observed necessaryto we the arbitrarilyassignedburst. All msps of dally falloutvaluesindicatethe burst assignmentusedfnccmputlng the deoay correction. Lkilessotherwiseindicated,all radioactivityis r~orted in unitsof disintegrationsper tinuteper equarefoot of law for the decay of fissionproductactiti~ has been= throughout. l?m maps of dailyfalloutincluieonly the dati from the land stations, since thereis considerableuncertaintyin the ship data. The locations of the shipswere imperfectlyknown and the procedures for amidimg cross-contaminationof samplesin handlingati mailhg, particularlyon shipsexposedto heavyfalloutat some time d@ng their voyage,were not adequate. T& ship data were utilizedin the drawizgof isolinesof actitityon the falloutmaps lndin the interpretationof the land stationdata.

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Tlm bwsta of the Caatle eeriesare given in Bikini Atoll, tlm swceeding four from barges In the Bikini lagoon ad th last on Mwetok Atoll. As alxmn in Table 2.1, mat of tlm rudioactiw CMXIS crealxd tb aloud In levelsbeyoxd the reach of routinemeteorological obeermtlxma, For this reaem, it ha been iqosslble to prepare ~ lt variom levele. Tlm netwrk of war air observing statlma in the tmgics is extrmmly apsraelt best, and uid repcmta ld~cent areas eatabllshedespeciallyfor this test sties. Eh8n

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tlwrefore,be computedlt levels above m ,000 ft. ati are doubtful even at lower levsls. All trajectoriesgimn in this reportwere Tb teqmraturs eomdlngs for all of the Castleburstswere very similarin theirnmjor features. There uare no pronounced inversionsIn the lower layers (exceptfor an invsrslcaat lbout 7,m feet ddng Romeo). Tb air was qtite mist up to lbout in tlm qper troposphere. TTlm tmpopause uas betuaen 8$~ lti 5b,000feet tith mry stablelaws rates in the louer stratosphere above. The winds obtiinedfrom observationsnmde at or near each of th shte are shownin Figure 2.1. h first burst of the Gstle series,Braw, was detonatedft’om res~t~ cloud of radioactivedebrisreachedto m, 000 feet with th bee of the mushroomat lbout 60,000 feet. T&J tzopopause at this time was at about n,OCNlfeet, so that th’ mushroomof t~ extended to about 6,000 feet, tith llght westerlyulds increa~ tith altittieto a maximumof about hO knots at 3%0,000 feet, were easterlyat about x kmts. Trajectoriesof the louur parts bf th cloud are ahonn in i?igure2.2, but dortmatdy, no tra jeotorles can be constructed wlrxlsIn the lower stratosp-e, so tint this portionof th OH ment of the cloud abowe 1~,000 feet lre available. &nwer, it 18 Tlm daily falloutmaps for the pcmiod followingth Bravo toot are particularlyMx3restiag In that th backgroundof fission productactivitymm prewiouetests was negligibleand the suc~ areas of falloutfrom day to day is more easilyseen.

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lgreant with tlm few uimd obsamtiona availablein t& upper Wpar le-1 oastmlias oontri~ted to thla falloutllso. far t& dams to rernin in the tropioalUtitties. By far the latitu%s of each hsmlsplmre,partloularlyin the Americas. An exaqle of tlxisean be seen in tlw eouthueslxm Wted Statesb the ptiod beginningMarch 15. At this t~, l deep low pressure fallout ~1~ occurredduring the first t!nwe daya of tlmperiod wmre aevurelstat.lonareportingprecipitation the falleutoccumwd In tb -on dmlmated by the southwesterlywimis and was not precipitation was more uidesvreadIn thin oaae and nmy hava had T& second burst of the Castle series,Rawo, also b~st of the sanM order of maznittiel8 the Bravo test. at 62,~ feet. The wind observations associated with this b~st showd light easterly wtxxisat vtrtually all levels increasing b speed l-e 80,000feet to a tim of 92 knots from the SE at the top of the highestobservation,9$,000 feet. Althoughthe trajeclarles

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and then eastwardwithina very short time. Tlm lowest levelsconlogicaldata is unoertiln. Winds b the dratoaplmrs up to the level of the too of tlm cloud wre probablyfrom the east, oarr@ng most of the mushroomwestward. Although alnmsta month elapsed bstuaenthe firstand seoond present to seriouslyinterferemith attemptsto tracethe prognm of th secozniclod by an examinationof falloutdata. For example, an I.norease In depositedactiti~ occurredat aoms atationa In Centraland SouthAmerica on Mroh 31 and April 1, sevursldays before the meteorologicaltra$sctorieswould indioatethe arrival of debris. It is not certainif this is due to the completelack of meteorologicalobser=tlons In the EasternPacMic and the winds were really strongerthan assuaed,or that tb debrisuas actually from tlm Bravo burst. (Nob: Stice all falloutdata is extrapolated to 100 days after the assignedburst, valuesassignedto Wferent bursts cannot be compareddirectly. The extrapolationfactordependsI both on the day of tlm burst and on the day the ample was counted. For th areas mentionedin this paragraph,=luas assignedto burst 2 would hve to be increasedby about a factorof three if the delmis were assignedto burst 1). is good etidencethat debris from this burst Ws arrivedover t-he kited States. Again, as when fresh Bravo debriswas present,fallout seemd to occur irrespectiveof the occurrenceof precipitation. The progressionof debriswestwardfrom tb test site appearsto bve been more rapid than indicatedby the low-leveltrajectories at ~,000 ad 10,000feet, at least for tb first few days following tb burst. Whethr the arrivalof debrisat yap and hror on March 2’9 is a result of transportof materialwestwardin the stratospheric Again, as with Bravo debris,tbre was a markedtendency for th falloutto occw in the tropicalareas,with occasionalincursionsinto Koon, the thirdburst of t~ series,ms, by far, the least powerfuldevice tested,with a field of 110 KT. It was detonakd at Bikini at 1820 GCT, April 6, 19%, but cloudyconditionsprevented

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aacurateobservationsof tlm character of the clod. Presmbly, the tip of the mushroomws at, or slightlyabove, tlM tropopause, light southerlyabove to about 30,000feet,becomingwesterly about 3M0 knots h the tropopause. &cause of large amountsof it was impossibleto trace tlxsMetoq of tb debrisfrom Koon. about to the north of the Marshal.lsfor many days and the upper portionmoved eastward,remainingsouthof the Uuaiian Islands, reachfngthe southwesternstabs on April 13. No falloutstati~ nported debriswhich can be definitelyassignedto this burst, althoughit is likelythat some of the activityassignedto Romeo Is a mhture of debris from the two bursts. NO fallouthas been aueignedto Koon In this report. The fourth test of th! series,Union,detonated at Bikini at beaomingwasterlynear the tropopauee,and strongeasterliesabove 70,000 feet. Trajectoriesof this burst are shown in FiguPe 2.5. in Mexico or along the Gulf coest until &y 5 or later. hUout at Medford, Ore.,on I%y 2 and In the wstern stateson the following days is b good agreementwith the 18,00o-footmeteorological trajeatary. It la very possiblethat the lack of meteorological since debrisarrifig in Cenlmaland South Americaon May s was most likelytransportedat these levels. Falloutto tk west of Bikini seemedto be in good agreemnt with the trajectories.It should be noted thst ewn thougha month had elapsedsince the last tropicsand it is by no means certainthat the debrisassignedto biuI is not from an earlierbmst, or that some of the actitity assumed to be from Romeo is not actuallyfrom Mon. Bikhi at 1810 GCT, May h, 19%. It was a high-fieldde~ce

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h cloud naehed 110,000feet. Altho~h the winds, in g~, were slxllarto thoseof the prwloua bursts,tlm reacbd Hexiao City on Hay 8, and falloutwas widespreadover tb uestem plalne statesld the Roekloeby ~y 9. Falloutfrom for s period of sore than l week. TIM fslloutfrom Xsnkee in tMs lny of the otlmr tests of tlm series. Tb west~rd noving debriu lppearedto prooegdfaater than India ted by the low-leveltrades, reachingKoror by &y 6 lnd Mngapore by My 9. Again, It is VWY possiblethat high-leveleasterliescarriedtha debris, alnce the detonatedfrom Eniwbtik. It occurredlt 1820 OCT, May 13, 19%, lnd um of l somawlmtlower field than tlm other high-fieldteats of the 6erlea. The resultlngcloud reacbd 72,000feet. TIM easterlyulds extendedto 20,000feet, with light westerllealbove (Figure2.7) began with a slightlygreatercomponenttowardsthe north tbn for the pretiousbursts. is virtually~ossible to distinguishbetweendebris from the two b~sts. An lttempt to separate the two sourcesof debris WJ made for tlm flrat ueek follouLngkctar, but was not atten@ed beyond this time. Daily falloutmaps for tlw re~inder of the month, Hay 22-31,are given with lll data extrapolatedto 100 daya after Howewar,it is likely tlat the rnjor portionof the falloutreported on thue daya orig~ ted from Yankee. To convertthe reported lctitityto 100 deya lfter Yankee, lsauiuing the debris originating from Yankee, the valtws gimm on the maps shouldbe Increasedby

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are not skun. Rather,a -p showingth averagedailyfallout for tlw month is given,togetlxwwith tim nuder of days for which data uas lvailableat each station. Again, the extrapolaticm is baaed on Nectar, lnd actitityis shoun at 100 days after burst. It is llso Mkely that the major ption of the fallout in Jme originatedfrom Yankw and all.valtms dmld be Increased by lbout 25% to @m valuesat 100 days after yankee. Althoughthe discussionof the transportof debrisin the atmosplx3rehas been confinedto essentiallyhorizontalha jectories, the actualpaths of individualradioactivepartioleaare complex, three41menslonalphenomena,influencedby tla fall velocitiesof the particles,atnmsphericturbulence,rain scmenging ati

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Tlm total world-widefalloutfrom each of the Castle (excamtKoon) and from the whole series has been oomputad basis of resultsfrom the monitoringnetwork. Since none stitions were locatedinsftediatelyd~wnwlndof the test area so as to experiencefalloutin the first day or two follow@ a detonation,it is apparentthat by far tlw largestfractionof A COmOSite map for the completeseries,showingthe total of au falloutoccurxzhgthroughJune 30, 19%, and decayedtm July 1, 195b, is slmn in Figures3.1 and 3.2. These naps contain tk cumulativetotil of all debrisdepositedon tb networkfrom b July 1 on th basis of the burst assignmentsindicatedin ApD@~ A (exceptfor falloutoccurringafter May 21, which was reextrapolatedto Yankee, see Section2.6). Isclinesof activitywere titerpolati betweenslationsad To obtain the total falloutdue to each of the individual tests, the follouingprocedm, was used. At each s~tion, all tations,falloutoccuming after May 21 was not considered,since there was aom doubt aa to burst assignment.) ti the event tht data were missingfor an occasionalday at a given station, the for a number of days, the sum was enteredin parenthesasand indicatedas a lower limit of “activity.holines of actitity-re drawn and tb total falloutcomputedby nurmricalintegration.

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It is not appropriateto comparethe resultsfrom the w?rioua testswithoutfirst consideringthe time periodsbetueen tests. For example,falloutfrom Bravo was not nwskedby later debrisfor about a month in the regionof tests,and couldbe identifiedfor an even longerperiod h regionsremotefrom the test site. @ the other hard, lhiondebriswas quicklyovershadowedby fallout from Yankee,vhich occurrednine days later. Th world-widedistributionof falloutfrom Bravo is shown in Figures>.3 ad 3.4. Assignedto the burst was all falloutfrom the periodfrom February28 to April S, 19%, with th exception of debrisin l limitedarea whith was determinedto be from Romeo b 100 days after b~st, was 1937 d/m/ft2,for a total falloutof migacties, or megacuriesas of J~y 1, 19% Mgures 3.5 ad 3.6 show the totalRomso falloutfrom the time of the bursts throughhy 3, 1954. The2world-wideaverageactivitycmies, or wgacurieson July 1. No debriswas assignedto the thirdbursm, Kcon. Falloutfrom Union (Figures3.7 and 3.8) coversth period throughMy 12, a somewhatshorterperiod than the<first two bursts, averagefalloutwas 281J dimfftat 100 days after b~st for a total of mgactiies, or megacurieson July 1. Yankee ctiative resultsare given in Figures 3.9 and 3.10. Debrisuas specificallyattributed to this byrst through Hay Z1. However,much af th falloutwhich occurredbeyond this period also originstid fioR Yankee so that the total falloutis undoubtedly much greaterthan t~ valuesgiven. Thro~h May 21. Yankee fallout after bmst. Correctedto July 1, 194, ttis VSIU =omes Nectarfalloutis shown in Figure 3.11. Since this burst f ollouadthe powerfulYankeeburst by only nine days, debris fr~ kctar is identifiableas such only for a few days ad in the region

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It is possibleto conqm’et& total falloutobeervaddting the Oautle serieswith tlm luxmt of bets sctitityproduced. Assumingthe relatlmnohipsbhmen fissionyield and totalbeta valid the beta •a~ti~b f= produotsfmm l nominal beta aativltyprochmd h the Mstle is sbwn h Table 3.1. TotalBeta Activity hoduts in Castle series A comarison of the observedfalloutfrom t~ first …