World-Wide Fallout from Operation Castle (Deleted)

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WORLD-WIDE FALLOUT FROM OPERATION CASTLE 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 POW WORLD-WIDEFALLOUT FROM OPERATION CASTLE 10. CROCIAM LLCYCWT. PROJECT. TAW ARtA A WUW Ualt MUYIIIS United States Atomic Energy Commission Technical Information Service Oak Ridge, Tennessee Approved for public release; unlimited distribution. This report has had the classified information removed and has been republished in unclassified form for public release. This work was performed by Kaman Tempo under contract DNAOOl-83-C-0286with the close cooperation of the ClaSSifiCatiOn Management Division of the Defense Nuclear Agency. world-wide network of gummed film stations was established to monitor fallout ollowing Operation Castle. Although meteorological data were poor, a general conection 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 incursionsbecame more evident. Outside of he tropics, the southwesternUnited States received the greatest total fallout, abou 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 Totalsfor Mividual Tests.......... The work reputed on herewas perfonaedunderthe direction was establisbdby the Healthand SafetyLaboratory,New Pork coordinatorof the program. Many helpfulsuggestioriswerereceivedfromcolleaguesin the Pooler,Jr., and Leo R. Quenneville. The staff of this section performedthe laboriousand peinetaringplottingof data and preparation of the finishedmanuscripts

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Winds Aloft for Castle Events. ..............7 &9teorO1OgiC81ti838CtOri88for Burst No. 2, Romeo .... 10 TotalF8lloutFrom Rode, Atlantic Hemispbre.

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cal datawerepoor, a generalcammotionof troposphericflow patternstith observedfalloutws evident. Therewas a tendency for debristo remainin tropicallatitudes, with incursionsintotti temperate regions associatedwithmeteorologicaldisturbancesof tlm receivt3d in Japan. The total world-wide falloutup to July 1, 19%, from the castleseriw outsideof the imediate testarea,is estimatedto be about Jf thz totalfissionactivity produced. The maimurnfallouton any day at an individual stationin the It is concl&ed.thatthe pmbabilityof earlyfallout in in the wintermonths. .

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indicaticns that the arbitrary system IJBSin error, the actitity was reassigned to the appropriate burst. In the case of observations in the Pacific and adjoiningregions,it was usuallypossibleto deterzinethe burstrespomiblefor the actitityfroman examination of t.Fletrajectories of the debris in conjunction with observed increases in radioactivity.Elsewherein the world,it was ordinarily necessaryto we the arbitrarily assigned burst. All maps of daily falloutvaluesindicatethe burstassignment used in computing the decay correction. Unless otherwise indicated, all radioactivlty Is reported in units of disintegrations per minute per square foot of law ior the decayof fissionproductactivity has been used‘throughout. The mapa of daily fallout incltie only the data from the land stations, since thereis considerable uncertainty in the ship data. The locations of the ships were imperfectly known and the procedures for avoiding cross-contamination of samplesIn handlingand mailing, particularlyon shipsexposedto heavyfallout at some time during their voyage, were not adequate, The ship data were utilized in the drawing of isolines of activity on the fallout maps and in the inwreta tion of the land station data.

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therefore, be computedatlevals abov8hO,Wft. andaredoubtfti man at lowarlevels. All izajeotoriesgiven in this report wera The temperature8omddnga for all of t2m Castleburstsware immious inthelowerlayara krceptforanlnvarsionatabout 'I,000feet dming Rome). Th6 air was quite moist up to about of thel shot8 are shouninyigure 2.1. The first burst of tIm Castle series,Bravo, was detonatedfkma resultingcloud of radioactivedebris reachedto l&OQO feet with extendedto about 6,000 feet, with light trestarlywinds increasing with altittie to a maximumof about 40 knots at 35-40,OOOfeet, winds inthelouar stratosphse, 80 tbtthisportionoftbb olopd me& of the aloud above 100,000feet ara available. &war, it is Thsdaily falloutmap for the period following ths Bravo bat ara part&cvilarly inimeatisg in that the beground of fi88iOn are88 of falloutfrom day to day ti more aa8il.yseen.

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it ir en- possiblethmt rtratospheriodebrisaoplng dth tha 10% to MoH, dthocamional asmrcrim3into the more temperate htitocb8 of each h8nd8phare,psrticularlyin tbe kmwicas. An axampleof this oanbe8eminthb mathweatarn kitedstates in that.tId.8falloatWa.8independent of precipitrtion. The highest f8l'l;oPt~valUi&occmred durbg the fir8t'f&8eday8 of the period r&uilar8arie8 of event8 occwred in the period March a-25, rlthaugh burst of the same orderoflnagaituierl thekwo test, was detonated from a bwge at1830 WE, March 26, 19%. The reslrltingcloud of debrisreached to llO,OOO feet, with tk bass of the nmshro~mtop at 62,000 feet. The wind observations8SSOCi8teddthttds burst speed above 80,000feet to a Wtm of 92 knot8 from the SE at the top of the highest observation,95,000 feet. AlthoUghthe trajectories (Figure.2.3) at all levels in the tropospheremmed westward

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and then eastward within a very short time. The lowest 1~818 continued westward and the 18,0001foot trqjectoq appeared to cttcpb bsok towards the United States on the 28th, elthotlghthe mteorolevel of the top Of th8 cloud wre probablyfrom the e88t, o8rrying most of the mu8~oom westward. of debrir. It is not certainti this is due to the CoTqlete18ck of x&eoroEOgiCal obsermtions in the EasternP8CifiCand the winds were really rrtrongerthan 8ssumed,or that the debriswas 8CtU8lly to 100 d8ys after the assignedburst, Values assignedto diffe?ent bursts cannot be compareddirectly. The extrapolationfactor depend81 both on ths dey of th? burst and on the day the eample~8s counted. 2 would have to be increasedby 8bout 8 factor of three if the debris were assignedta burst 1). By Aprils 2nd and 3rd increasesin activityare etidentalong the Gulf Coast of the kited States and certainlyby th8 tth and 5th there is good evidenceU&debris fkom this btrrsthes arrived over t-k kited States. Again, as when fresh Bravo debriswas present,frllout seemed to OCCUF irrespectiveof the occurrenceof precipitation. The progressionof debris westwardfrom the test site appearsto have been mom rapid than indicatedby the low-leveltrajectories at 5,000 ard 10,000feet, at le‘astfor the first few days following is 8 result of transportof nsrterialwestwardin the stratospheric easterliesor in fester-than-observedlow-leveltr8desis not certain. Again, 8s uith Bravo debris,there ~8s a marked tendencyfor the Koon, the third burst of the series,was, by fer, the least powerfuldevice tested,with a yield of 110 m. It was detonated8t Bikini 8t 1820 GCT, April 6, 19%, but cloudy conditionsprevented

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aaaurate observations of the character of the aloud. Presronably, ths top of the ~~u~hroom tms at, or slightly sbow, the tropopause, which was at 53,000 feet. Ths winds wsre easterly to 5,000 feet, light southerly aboveto about 30,000 feet, becoming westerly about 30-40 knots to the tropopause. Because of large amounts of fallout from the second burst, which occurred eleven days earlier, it was Mosaible to trace the history of the debris from Koon. According to ths meteorological trajectories (Figure 2.41, the lowest laysrs moved uestusrd, the mid-tropospheric portion milled about to the north of the Marshall8 for manydays a& the upper portion mooedeastusrd, remainingsouthof the huaiian ISlSnd6, ~~hi4g the southwestern states on April 13. No fallout station reported debriswhichcanbe definitelyassigned to tMs burst, although it is likely that some of ths activity assigned to Romeo is, a mixture of debris from the two bursts. No fallout -has been assigned to Koon in this report. The fourthteatof the series,Won, detonatedat Bikiniat 1810 GCT,April 25, 19%. was also a high-yield burst, wMch reached typiual,easterlytradesin the lower levels, light winds abow, becoming wstsrly near the tropopause, and strong eestarlies abow 70,000 feet. Trajectories of this burst are shown in Figtie 2.5. If tb 30,000- ati 40,000-foot tra jectorG6 are correct, wry little fallout was evident from these lewls, since no debris uss detected in Wsxico or along the Gulf coast mtil Hay 5 or later. Fallout at Medford, Ore., on May 2 and in the -stern states on the following days is in good agreementwith thb 18,000-footmeteorological sincedebris arriving in Central and South America on May 5 uss most likely transported at these levels. Falloutto the west of Bikiniseemedto be in good agreemnt with the trajectories.It shouldbe notedthateven thoxh a month had elapsed since the last tropicsand it is b no mans certain that the debrisassigned to hian is not from an earlier burst, or that some of the activity assumed to be from Romeois not actuallyfrom &ion. Yankee, the fifth burst of the series, uss detonated from Bikini at 1810 GCT, May 4, 1954. It was a Mgh-yield device

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rpperred to proceedfaster then Indicatedby the low-leveltr8de8, Of the 8erie8. Tim rerultingaloudreached 72,000 feet. Ths thti tlllm.&ily frlloutm&p8 for the reminder of the month, 16y 22-31,are given with 811 data extrapolatedto 100 drya after However,it is likely that the IU$E portion of the frlloutreported on thb8e dry8 originatedfrom Ymkee. To convertthe reported rativityto 100 days rfter xmkee, 888u11dngthe debris originating

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To ComerYe space, daily falloutmnps for the monthof June are not 8bnl. Rather, a map show& the averagedailyfallout for the monthis glwm, togethervith th3 numberof daysfor which data VII mailable &each qtatian. Again, the extrapolatlcm la based on Nectar,and actitityis shounat 100 days after burst. It ir 8180likelythatthe majorportionof the fallout In Jme ori by about25 to givevalue at 100 da$s after Ysnkee. Althoughthe discussionof the transportof debrisin the the actualpathsof individual radioactivepartiolesare complex,

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(exceutKoon) and from the whole series has been oomputedon th b88i8 of reStit from the monitoringnetwork. since none Of the A compositenmp for the completeseries,showingthe total of 811 felloutoccurringthroughJune 30, 19%, end decayed to July 1, 1951r,is rhmn iu Figures3.1 and 3.2. These maps contain the cumul8tivetots1 of 8ll debrisdepositedon the networkfrom Febrmry 28 throxh Juue 30, 19%. The debris was extmpolated to July 1 on thb basis of the burst assigrmentsindicatedin Ap~endti A (exceptfor felloutoccurringafter tiy 21, which was reertrauolatedto Yankee, see Section2.6). the aver8gefalloutfor the uusld was Computed,by numricel To obtain the total falloutdue to e8ch of the individual tests. the followingprocedure,~8s used. At each station,all fallout assignedto the given burst,8s indicatedon tb maps 0 there tw8 some doubt 88 to burst assigmt?nt.) In the event that data were missingfor 811 occ88ion81 day st 8 given station,the for 8 number of dey8, the sum was enteredin parenthesesrnd

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It is not appropriate to compare the results from the various tests dthout First considering the timeperiodsbetweentests. For example, fallout from Bravo was not masked by later debris for about a month in the region of tests, and could be identified for an even longer period in regions remote from the test site. On the other ha&, Union debris was quickly overshadowed by fallout from Yankee, uhich occurred nine days later. The world-wide distribution of fallout from Bravo is shown in Figures 3.3 aad 3.4. Assigned to the burst was all fallout-from the period froa February 28 to April 5, 1954, with the exception of debris in a limited area whichwas determined to be from Romeo (See Appendix A). The average activity of this fallout, corrected to 100 days afbr burst, ~8s 1937 d/m/ft2, for a total fallout of msgacuries, or ,asgacuries as of July 1, 1954. Figures 3.5 and 3.6 show the total Romeo fallout from the time of ths bursts through May 3, 1954. .The2uorld-wide average activity at 100 days after burst was l44s d/m/ft for a total of *egacuries, or regacwies on July 1. No debris was assigned to the t&VI burst, Koon. Fallout from Won (Figures 3.7 and 3.8) covers the period throughPzay12, a somewhatshorter period than the_ first two bursts, since Psnkee UN detonated only nine days after Union. ‘The worlcbide average fallout was 284 d/8l/ft at 100 days after btpst for a total I of nsgacm’ies, or aegacuries on July 1. Yankee cusnilative results are given in Figures 3.9 and 3.10. Debris uss spsctiically attributed to this burst throughHay 2l. However, much of the fallout which occurred beyond tizb periodalso originated from Yankee so that the total fallout is u&oubtedly much greater than t3 values given. Throush May 21. Yankee fallout msgacuries at 100 daxs after burst. Corrected to July 1, 1954, this value becomes Nectar fallout is shown in Figure 3.ll. Since this burst follomd ths powerful Yankee burst by only nine days, debris from Nectar is identifiable as such only for a few days and in the region near the testarea. 2T~s +‘allgut from Nectar anxnmts to a world-wide average of 81 d/m/f t , or. &gacuries, at 100 days after burst, negacuries on July 1, 19%.

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rrlid the bet88o~~~f~pprodUOt8f'roa 8 Aondxul A comperisonof the observedf8uOUt from the firsttwo eVent8

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The snmll percentage of total debriraccounted for by the ob88rHng netwotiis somwhatpuzzling. Althoughitmust be aesumed 4% from the by 8erie8.b Simzetb three most powerfulburst8 of the Carrtle8erie8were considerablylarger than the Ivy Mke teet, it is po88iblethat a hrgar fract5aaof tha debris ua8 transportedinitiallyinto the Th8 total falloutfrom the Bravo teit (Fig=88 3.3 axi 3.b) clearly 8how tb bmdency fortha majoraotivityto reaain near tki8ourcelatitaxie. In marked oontraet idth the f8lloutfrownthe Iwo Jima than on any of the other PacificIslands. The difference Thts oell is almoSt non-existent,in the man, during the winterand *Tb flgare8given in Table 6.2 of reference(2) have been revised following8 recalibrationofthe countingequipment. The revised

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early spring, when the Aleutian lows are farther south. As the western cell of the Pacific high intensifies, more debris can be carried toward the north, so that by the time of the Yankee test (Figures 3.9 and 3.10), in early May, a larger fraction of the fallout occurred in Japan. R-estrmablp, tests in the summerand early fall muld result in tb greateat contamination of the Japanese Islands, while winter tests would result in the least. Also during the winter months, precipitation in Japan is at a minimumexcept for a narrow zone on the western slopes. For most of Japan, maximumrainfall occurs during the warmseason, tith the heaviest rains in June and September. Similarly, in other inhabited regions likely to be most affected by relatively early fallout, ~Mexicoand Central America to the east and the Phlllipines to the west of the test area, the dry seasonoccursin the winterand the rainiest in the warmer months, so t!mt here too, fallout would be at a minimumfor winter tests as comparedto otherseasons. The highest fallout reported on sampling day …