Operation Castle - Project 2.5B, Fallout Studies (Deleted)

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Pacific Proving Grounds Headquarters Field Command Armed Forces Special Weapons Project Sandia Base, Albuquerque, New Mexico This is an extract of WT-916, Operation CASTLE, Project 2.5b, which remains as of this date. Extract version prepared for: DEFENSE NUCLEAR AGENCY

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Chemical Warfare Laboratories Army Chemical Center, Maryland Headquarters Field Command Armed Forces Special Weapons Project Sandia Base, Albuquerque, New Mexico Approved for public release; unlimited d stribution. ,. TYPE of 6CPORT k PERIOD COVERED ;. PERFORMING ORG. REPORT NUMBER to. PROGRAM ELEMEMT,PROJECT, TASK 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 DNAO01-79-C-0455 with the clcse cooperation of the Classification PlanagcrnentDivision of the Defense Nuclear Agency.

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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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The objectiveof this grcje~%was to docurmt the charactcAstics of the close=-??aradioactivefallout resultingfrom the surface land or water detonationsof high field nuclsar devices in order to associatedwith the residualcontaminationfrom such bursts,(2)the tsticsand signific??nceof the radioactivedebrisdistributedby baso The objectivewas accomplishedby samplingthe falloutwith interzdttentfalloutcollectorsand by analyzingthe particulateand Fallouts’%ationswere set up in varyingarrangementsfor Shots When significantfalloutoccurredat an islandafter any of these shots,it apparentlybegan to arrive there within six minutas after the detonation. The maxlnrumactivityper samplingtinm intmval resultingfrom Shot 1 ad other sho’tshavingyields of the same order of msgnitudearrivedat all samplingstationsduringthe first hour after the detonation. Extrapolaion of the beta actiti.tiyhad indicated Most of the activityhad atived at a given stationwithin 3 to 6 hours after the detonation,with small amountscontinuingto arriveup to at least 12 hours after the detonation. Gama dose ratesat the shot atoll 1 hour after each shot wers estirrtodto be as followsfrom data collectedby this projectand Rad Shot 1$ 1600 to 2900 r/hr along the northernislands,160 to side of the atoll. Shot 2$ IMO ta 4700 r/hr on the northwestislandsclose to ~und zero and 2.4 to 14 r/hr on the n=~ng islands. ,Shot3$ 41.or/hr at Uncle, justwest of ground zero 10 to Shot 41 160 to 440 r/hr on the north and northeastislands, and OJ to~7br elsewhere

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ity of groundzerosdroppingto 17 to 32 r/hron the islandswestward and 1 to 6 ?/hr eastwardfromgroundzero. wrticle sizedistributionwith distance,direction,ortime. The approximatenmel-~fian diameters of saqles collectedrangedfrom 5 to 20 U. Up to forty-threeper cent of theseparticleswere under fron Shot3 appearedto be mostly crystalline, ashlilm, or fused. In particlesfrom149 to 1000P, the percentageof particles tith actiti.ty on the cutsidegenerallyincreaseddirectlywith size, was scattertxi randomlythroughoutthe remainingM per centof Thcr; was no appareritcorrelationbetweenthe locationof activity cn the particlesand theirphysicalappearance. No conclusionscouldbe drawnaboutthe presenceor absenceof

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Thisrep+ is one of the reports presentingthe resultsof the interestedin otherpertlmnt test information,refcranceis nmde to Miltta s smmary reportincltiesthe followlng aggestions in the phnning and executionof this Many peoplehave made contributionsto thework describedherein; Liederand MissCarnm Paulhave aIl contributeda greatdealof tins ‘7.1RadiologlmlWfetiyhit, and is usedwith the pwmiaelonof

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IIX Spider and ‘XYayswith Cups .......l 21 Interiorof the IFC, Showingthe F“tor and Gear Glass Jars for LiquidFalloutMunted on the Emmple of Shot 2 IkcsyOurve Plottedto Sho~s 2 and 1 Zero Time l *** 48

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Variationof Beta Activitywith Time,Shot 1, Variationof Beta Activityuith Time, Shot 1, Vsrlationof Beta Activitywith T%ns~ Shot 1, Variationof Eeta Actitityuith Time$ Shot 39 t’ariatio~lof Beta Activitywith Time, Shot 3, of Shot 4 Fallout.. ......~~~

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Theoreticaland &perimental Ratiosof the Area of the PhotoPeakto Totil Area and Fractional Factor to CorrectArea of Photopeakto Numberof The M@ 1.6 .%v Photopsk as a Functionof Time Prepemtlon of particleMedium;kveloping and Examinationpositionof Strippix Film .... Shot 3 White, Fused Particle210-420 on the outside ............ Rample of a WLced Particlewhich w Uniformly Bikini IIN Land Stationhta *U*. Beta Decay Ikpcnentsof Shot lSize Graded Samplee Actititybncentrations of Shot 4, How Beta Range Measurement . 1600 kevhmma Ray inLa~O to other _

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Semplesfkom How Island. ..ll.ll. Beta Activitiesat CountingTime, Shot 1, 30 min Beti Aotiti.ttesat Canting TimB, Shot 1, 5 and Beta Activitiesat CounttigT*, Shot 2, 5 h Beta Aotivittesat CountingTime, Shot 29 30 min Mta Activitiesat bunting Tizm$ Shot 3S 1 m Eeta Aotlvf.tiesat CountingTim, Shot 3, 30 min Beta Aotlvitiesat Oounting‘MM ~ Shots 4 and 69 Rad Sde Gamma Suwey Mxtings After Shot 5 . . Rad Safe @nna Summy Readings After Shot 6 . .

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The objectiveof the projectwas to documentthe characteristics of the closeqn radioactivefalloutresultingfrom the surfaceland or water detonationof high Weld nucleardevicesin order to provide infornntionfor Wne evaluationof (1) the immdiate hazardsassociated with the residualcontaminationfrom such bursts, (2) the mechanism of particleformationand distribution,and (3 ) the characteristics and sigflicance of the radioactivedebrisdistributedby base surge phenomnon providedthat a significantbase surge is causedby surface To accomplishthe cbjective,the followingspecificphysical characteristicswere documentedwhere possible. a. Beta activityand Lhe time at which it arrived, e. The activityper unit weight or volume of liquidand solid tion of actititywithin the stied particles. positionof radioactivedebris (fallout)on the earthtssurface. The degreeto which falloutmy Influencemilitaryoperationsdependsupon the rmgnitudeof the significantradiationfield and upon the ability to predictthe extentand locationof the field. The amountand activityof the falloutis @marily a functionof weaponmeld and conditionsof detonations.e~ whether the detonationhas talom place in the air, on the surfaceof land or water, or underneaththe surfaceof land or water. ‘lhisinvestigationseeks to extendthe knowledgeof such variationsby studyingthe fallout resultsfrom high yield nuclear devices. The resultsfxvm this projectwill aid in (1) determining the significanceof falloutfrom surfacedetonationsof high @eld

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weapons, (2) predictingthe falloutpatternsresultingfrom other contaminationprocgdures~ In additionto thesebasic investigations, operationCASTLEresultswere expectedto providethe basis of a theoryfor the rmchanimof particleformationin the cloudand to supply data relativeto the differencesbetweenfalloutresultingfrom land and water suvfacedetonations. Resfdualcontamination resultingfrom falloutwas initially in residualcontaminationwhich was ~ltarily significantfor all types of nucleardetomtions exceptah bursts. Experimentswere designedto documnt the falloutfrom both the operationJANGLE3 and are of limitedapplicabilityto the CASTLEtests becausethe yield of the JANGLEshot was very small and in desert sand ratherthan coral rock, WMle the main downwindpatternof falloutfrom IVY Mike shot went out to sea and was not instrumented. TIM JANGLEsurfaceshot denmnstratedthat a low fieldweapon could causea significantdegree of contamlmationand definitelyestablishedthe need for furtherwork on the contaminationproblemand associatedhazards,especiallyfrom opportunityto Investigatethe generalfalloutproblemresultingfrom the surfaceland bW8t of a high @eld nucleardetice. An unanticipatedbasa surgewas observedshortlyafter the CRJSSRCADS underwaterdetonation~. It appearsthat the base surgedisnot entirelyconclusive. Attemptsto studybase surge effectshave sincebeen mule at JANGLEand at som high explosivetests~ These experlmsntshave mt determimd whether the base surge is a carrierof study base surge characteristicsfrom surfacewater shot,

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The collectorswere desigmedto collectliquidand solidfallout to between1 * and 30 uin. The sanpleswere at least large enough to be analyzedby standardtauntingtechniques. Base surge estimationsfrGa work done by the Naval Ordmnce LaboratoryTask 152 indicatedt’.~atthe nmcimumradiusof the surge from or 15 miriafter detorationa Tinebase surgewas pri..xwzrilyexpectedfrom the surfacewater shots;however,Shot 1, detonatedon a reef, was instrumentedfor base surge %mples becauseit was thoughtthat the reef was so narrow that Hid shotwo.fldbe, in effect,a water shot~ Since ut collectorsin the regionwere ruggedlybuilt. These collectors heaviestfallouton the atoll cccu.rredwithti the first30 min after the detonationand tM t fall.outcontinuedt,ooccur more than 6 hr after the detonation which was the maYMum samplingtime of the IVY COlThus, two collectorswere generallyplacedat each station:(1) one sampMr~ at l-o-5-reinintervalsfor a totaltime of 24 min or 2 hr respectively,h documnt the base surge or early fallout;and (2) Eastcal~v,the same type of instrumentswere used to sample fallout on the surfaceland and surfe-ce water shots. anism and a housing (Figs.2.1-2.3). Each sectorcontaineda triangular trzy 3 3/7 in. x 10 in., anti3/4 in* deepo one traY at a time was exposedto fallout throqgh an opersingof equal size in the top cover. The tide end of each tray held four glass countingcups (1 in. In

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diameterand 5/15 in. high),positionedin a quadrilateralabout 2+ in. on a side. l%e cups were wated on the insidewith siIicQnegrease to producea tacky surface, This tacky surfaceheld almostall.particleswhich came in contactwith it; rainwatercollectedduring the samplinginternalwould not wash particlesfrom the tacky surfaceunless the particlesthemselveswere soluble. An 8-02 jar was fastened beneathan ope,nhgin the bottomof the tray to collectliquid fallout (Fig.2.4). A door coveredthe samplingopeningboth before and after The instrumentwas startedby an externaltiming signal. After a delay of 1 rein,the coverdoor opened and the first tray nnved into samplingposition. Succeedingtrays roved into positionunder the wver openingat set tim intervalsuntil the cyclewas completed; (Fig.2.6). The door then closedand the fia.chineshut itself off. At the time of the detonationan externaltiming signalactuated the clockwhich had been pre-setfor a short t~ delay before the door opened (l%lg.2.!3).At the erd of this delay micxwswitch~ in clockwas tripped,allowingtk currentto flow throughthe driting nmtor which in turn rotatedthe spider;the door openedand tray 1 sptderrti was ne longerclosedby one of the cams on the spider$ ticrosvc.tchC2 opened. I%is renved the currentfrom the clock coil and reset the clgck. The drivingmotor continuedto run until the cam under the next tray mowl over S3. When S closed~the currentpath zto the drivfngmotor was broken and the mo or stayedoff until the clock fitisbd another cycle. Succeedingtrays nmved into nosition under the rover Gpeningat set tim intervalsuntil the samplingcycle At the tire?of detomti~n a srming cam was restingon a microover the microswitch,S5, completinga circuitthroughR3, which was thrown and latched. After the last tray was in samplingpositionand the door closed,the spring cam agati rode over S4, breakingthe circuitsand stoppingthe instrument, Push-buttonswitch,S2, was used as a reset Stitchso that the tion. Toggle switch S2 was mountedtier the clockand was used to presetthe @ck. This switchremainedclosedduring the entire operafrom overshootingtheir position. Variablel-ohm resistorsand also lengthsof nichromewire were used. Where wire tindmg signalswere availableat a station,a minus l~ed to actuatetho IFC. Where no wire tting signalswere availab~ was used to actuate the lFC. I?tietiming signalswere initiallyused,

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where avaihble, becauseexperienceat Im indlcatetithat blueboxes were not always reliable. However,towardthe end of this operation blueboxsignalswere used where feasible,becausecf the satisfactory performanceof the mdlfled bluekxes. At the raft stations,the MC At the Bikiniland stations,the IFC and its batterieswere ueully mountedin concretefoundations(Fig.2l9). At the Bikini lagoon stations, t k equlpmmt was mountedon woodenplatformsbolted to 6(MnanNavy llfe floats (Fig.2.10). These floatswere mored to floatsin turn were tied to mring bUOYS furtishedby Helms and ?iarver,Inc. At the Eriiwetokti.ndstations,the IFC and the wooden batte~ boxes were dug into the groundflushwith the This pzvjectWtici@ted in Shots 1, 2, 3, and ded to participatein Shot 5. However,water wave damageto the statIons fmm Shot 4 made particiwtion in Shot 5 impracti@ l Generally, IFC~s were placed in groupsof two at Bikinilocations,aml eingly at the BikiFi raft and Eniwetokstationsl mere two IFC~s were on an islandor raft station,one was set to samplefor 12 hr at 30-mInintervals and the other was set to samplefor either24 sampleswere collectedfor Project2.6b to detertinethe degreewhich the base surgewas contributingto the residualcontaminationpattexvh The 5-rid.nintervalinstrumentsdocummted the early fallout and the 30-min titervalinstrumentsdocumentedthe falloutfor the mximum length of the possiblewith this instrument. where OXM IFC -S looatedat a stationor raft, it was set to sampleat 30-minIntervals The stationlocationsand tindmg intervalsare listedin Tables 2.1, 2.2, and 2*3 and shown in l%gs. 2.12 and 2.16. ately followingthis event,the pro:ectlsmain base of operationsat operationalsupplieswere lost. Th> long delay before Shots 2, 4, and chargedin the hot weatkr,requiringfrequenttrips to the stations Heavy seas in the BikiniLagoon causedthe cancellationof the Bikini raft stationprogram. TM rafts broh away from their moorings with distressingfrequency. Locatingand nmoringthe rafts In

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the lagoon prcved to be dange~-ousto personnel. Salt sprayand water made maintenanceof electricaleqti?~nt on the rafts difficult. minorityof pro,jectpersor.nel.were ak~lato work at the raft stations withoutbecomingseasick. only two of the origiml nine raft stations able after Shct 1 was removedfror.the rafts and used at land stations Since no sampleswere obtainedfrcm predictedbase surge region of any CASTLE shot,none of the desiredinformationabout the characteristicsand signtiicanceofthe radioactivedebrisdistributedby base surge phenomenawas obtained. Recove~ was carriedout on the fourth,fifth,and ninth day after Shot 1, the first day after Shot 2, the first and secondday after Shots 3 and 4, and the first day after Shot 6. A tio-mn team used a lo-passengerhelicopterto recoversamplesfrom the land stations. A secondtwo-manteam used an LCM to recoversamplesfrom the raft stationsafter Shot 10 TM recoveryteams removedthe spiderassembliesfrom the lFCIS$ placed them in dust-tightboxes$ and mmed them to the packingarea~ All locationsavailablefor packagingsamplsswere somwhat windy and usuallyin contamted areas. Packingwas done on an open barge near Nan after Shot 1, in a Tare tent after Shot 2, ha Nan tent after Shot 3, on Oboe, iri the re= of a closedt~ck twned On its side aftershot 4, and in a ten+.at m~r after Shot 60 The jars were renmed fmrn the trays and Psppedo The trayswere sume~d where possible,and a few samplessalectedfor decay masuremmts at the I%vject2.6b Elmer laboratory. Plastic‘snap-onncaps were put on the glass cups,and the trays were sealedwith alumlnum foil~ The trays and jars were returnedto Army ChemicalCenter,Marylandby a specialsampleretwn planewMch usuallyleft Eniwetokone or two days after reco~erywa3 cnmpleted.

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LEROY— . l 30 Min Interval Colloctom fig. 2.16 StationIayoti for Shot 6

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samplesaxxlthe areas fromwhencs they came~ (2) studyingdecay; (3) extrapolatingthe beta actitityresultsto estimatedactivitiesat _ling tire,and (4) stud@ng the acthity per unit weight or volume, The glass countingcups were removedfrom the trays,externally nessesof less than 2 mg/cm2. The tubes were nxnantedin verticallead ing brass plate was insertedbetween the O-M tube and the sample.~ The outputof the tubes was fed into Atomic Salers kdel 1060 havinga characteristicresolvingtim of 5 microseconds. The samplesin glass cups were countedfor beta actitityin the countedfor 10,000 counts, sampleswith activitiesless than 1000 cpn were countedfor 10 min. Each samplewas counted twice; in caseswhere the two countsdid not agree within one standarddeviation,athird countwas taken and tho three counts averaged~ It WZLS necessary to apply several correctionsin order to aP_ proximatethe disintegrationrate of the samples. The method ~st commonlyused to obtain the distitegrationrate of a sample is to comparethe sampleunder mnstderation with a known source countedin an identicalmmmr. However,there is no one known sourcewhich representsndxgd fissionproducts. The procedureused here evaluates the variouscorrectionfactorsin terms of the sampleitselfand thus avoids the errorsassociatedwith a tiect comparisonwl.tha singleisotopestandard. The procedureis as follows~ 1. The raw cpm were correctedfor coincidenceloss.~

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2. An 8.15-gm/cn?brass absorberwas insertedbetweenthe sample ~ the tube. This absorbereliminatedall beta …