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 Approved for public release;

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IO. PROGRAM ELEMENT. PROJECT. TASU ARE A & WORU UUIT NVYt3ERS Chemical Warfare Laboratories Army Chemical Center, Maryland Il.COMTROLLIWG OFFICE NAYE AND ADDRESS Headquarters Field Command Armed Forces Special Weapons Project Sandia Base, Albuquerque, New Mexico 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'pcrformed by Kaman Tempo under contract DNAOOl-79-C-0455 with the close cooperation of the Classification

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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 18holes88in 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 prodectwas to documantthe ch.aracterf.stics of the close4a radioactivefallout resultingfrom the surface land or water detonationsof hfgh yLelldnucleardevicesin order to provideinformationfor the evaluationof:(l) the immedfatehazards isticsand significanceof the radioactivedebrisdistributedby base surge phenomena,providedthat a significantbass surge is causedby The objectivewas accomplishedb-~samplingthe falloutwith When significantfallout occurredat an island after any of these shots,it apparentlybegan to arrive there Kithin six minutas after the detonation. The maximumactivityper samplingtim interval resultingfrom Shot 1 ani other shots having yields of the sawz ardsr of magnitudearrivedat all samplingstationsduring the first hour after the detonation. Extrapols 1rates as high as le3d.@.4 dpm/ftion of the beta actitilqhad indicated 1 to 6 min after the detonation, beastof the activityhad arrivedat a given stationwithin 3 to 6 hours after the detonation,with slrnllamountscontinuingto ‘arrive up to at least 12 hours after the detonation. Gamma dose rates at the shot atoll 1 hour after each shot wera estimatadto be as followsfrom data collectedby this projectand Rad Shot It 1600 to 2900 r/hr along the northernislands,160 to 630 rb on easternislands,and 15 to 43 r/hr along the southwest side of the atoll. Shot 2: 1100 to 4700 r/hr on the northwestislandsclose to groundzero and 2.4 to 14 r/hr on the rerariningislands. shot 31 ~0 r/hr at Uncle, just west of ground zero 10 to where. Shot 4:r 260 to 440 r/hr on the north and northeastislands,

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ity of== sero,droppingto 17 to 32 r/hr on the islandswestward and 1 to 6 r/hr eastwardfrom groundzero. Plithinthe atoll.,therewas no apparenttrendof radioactive Frticle size distributionwith distance,direction,ortime. The 5 to 2OP. Up to forty-threepar cent of th6separticleswere under 10 )1* Shot 1 particlesappearedto be coralor crystalline;those from Shot 3 appearedto be mostlycrystalkLne,ashlike,or fused. In particlesfrom149 to MOO ps the percentageof particles with activityon the outsidegenerallyincreaseddirectlywith size, whilethe percentageof undfortiyradioactiveparticlesgenerally decreasedwith size. Thesetwo typesof particlesaccountedfor about90 per cent of the radioactiveparticlesexamined. Activity Therm"s no apparentcorrelatiorrbetweenthe locationof activityon the particlesand theirphysicaf.appearance. No conclusionscouldbe drawn about the presence or absence of radioactivityIn the base surge,becauseno sampleswere obtaimd in

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Thisreportia one of the reparttrpreaentlngthe reeultsof the 34 projects pmticipating in the HU.tmy BffectsTestaProgramof Operation CASTLE, which indluded six tast d&oxHicms. For readers interestedin otherpertinent test Information,refmmce is nnde to b. Discussionof all projectresults. co A summaryof each project,includingobjectivesand results. d. A completelistingof all mports coveringthe Nllitary supersedesthe preliminaryreport;IT23-916,whichwas issuedin Yay Many helpfulsuggestionsin the planulngand executionof this Many peoplehave mde contributionsto the work describedherein; Liederand Miss Camn Paul have all contributeda greatdeal of time and energyto the preparationof this report. hb3t of the data in AppendixC was furnishedby the Task Group 7.1 Radio3.ogirxii.SafetyWit, and is usedwith the permissionof

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IFC Spfderand Trayswith Cups Exampleof Shot 2 DecayCurvePlottedto Shois l l 2 and 1 Zero Time Variationof Beta Activitywith Time',Shot 1, &g l l

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Variatiouof Beta Activityvith The, Shot 3, of Shot 4 Fallout of Shot 4 Fallout ...ce......

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Theoretical and ExperimentalRatiosof the Area of the Photopeakto TotalAreaand Fractional Factorto CorrectArea of Photopeakto Nunberof The ~a1401.6 SW Photopeakas a Functionof Time Shot 3 white, opaque, PoroG, L&Lw' l l l on the Outside . EniuetokIFC Station for Shot 6 Shot 1, Beta Actlvftyat Ssmpl~ Time ....

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3.13. ~IO$ and 3 Radioaatfve PartiaLe Amlysfs Avtwqpa of CsnnukitiveFeraentof Radioaative 30 xain Iuterpsl colleotors . Beta Activitiee at Coit&g*Tiie;Sh& jp i ah l Liquid Fallout Colleated fn IFC Traps ....

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The objectiveof the projectwas to documentthe characteristics waterdetonationof highyieldnucleardevicesin orderto provide infornstionfor t'neevaluationof (1) the immdiatehazardsassociated with the residualcontandnationfros suchbursts,(2) the mechanism of particleformationand distribution,and (3) the characteristics and significanceof the radioactivedebrisdistributedby base surge phenomenonprovid8dthata significantbase surgeis causedby surface To accomplishthe objactive,the followingspecificphysical a. Betaactivityand the time at which it arrived. 8. The activityper unitweightor volumeof liquidaid solid tion of activitywithinthe sizedparticlesr 3.2 MILITARYSIGNIFTCANCEOF THIS INVESTIGATION degreeto whichfalloutmay influemx militaryoperationsdepcsndaupon tha magnitudeof the significantradiationfieldand uponthe.ability to predictthe extent and locationof the field. The amotmtand activityof the falloutis primarilya functionof weaponfieldand conditionsofdetonation,ioe3 whetherthe detonationhas takenplacein the air,on the surfaceof land or water, or underneaththe surfaceof land or water. l'hiainvestigationseeks to extend the how18dge of suchvariationsby study@ the falloutresultsfrom highyieldnuclear devices. The resultsfma this projecttill aid in (1) determining the significanceof falloutfrm surfacedetonatfonsof high yield

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fieldsand conditionsof detonation,(3) emluatingscalingparameters, OperationCASTLEresultswere exnectedto providethe basis of a theory for the mechanismof particleform&ion in the cloudand to supply datarelativeto the dtiferencesbetweenfalloutresultingfrom land and water surfgcedetonations. Residualcontamination resultingfrom falloutwas initially observedat OperationTRINIW; subsequentatomictestshave resulted in residualcontaminationwhichwas militarilysignificantfor all typesof nucleardetonationsexceptair bursts. Experimentswere designedto documentthe falloutfromboth the OperationJANGLE2/ and are of limitedapplicabilityto the CASTLEtestsbecausethe yieldof the JANGLEshotwas very emalland in desert sand ratherthan coral rook, whCe the main downwindpatternof falloutfromIVY Mike shot went out to sea and was not instrumented.The JANGLEsurfaceshot demonstratedthat a low yieldweaponcouldcausea significantdegree of contaminationand definitelyestablishedthe need for furtherwork on the contaminationproblemand associatedhazards,especiallyfrom opportnnityto investigatethe generalfalloutproblemresultingfrom the surfaceland burst of a high yield nucleardevice. An unanticipatedbase surgewas observedshortlyafter the CMSSnot entirelyconclusive.Attemptsto studybase aurgeeffectshave sincebeen Illsdeat JANGLEand at somehigh explosivetests. Theseexpertints have not determirzdwhether the base surgeis a carrierof radioac?ivity.OperationCASTLEpmvided the first opportunityto studybaee surgecharacteristicsfrom surfacewater shot.

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The collectorswere designedto collectliquidand solid fallout samplesat preset, successivetime intervalswhich could be adJusted to between1 min and 30 tin. The sampleswere at least large enough to be analyzedby standardcountingtechniques. Base surgeestimationsfrozework done by the NavalO&name LaboratoryTask 152 indicatedthat the xmxima radius of the surge from the CASTLEdevices could be from 15,000 to 34,000 ft, dependingupon, the yield.of the devices. The phenomenashouldbe completewithin 10 or 15 tin after detoration. Tinebase surgewas primrlly expectedfrom the surfacemater shots;however,Shot 1, detonatedon a reef, was instrmented for base surge sanplesbecauseit was thoughtthat the reef wa3 so narrow that t&a shotwould be, in effect,a water shot. Since out collectors,inthe regionwere ruggedlybuilt. These collectors were set for l-tin intervals* Experienceat Ima indicatedthat the heaviestfallouton the atoll occurredwithin the first 30 I& after the detonationand that fallout continuedto occw more than 6 hr after the detonation,which was th8 marlmum samplingtime of the IVY colThus, two collectorswere genarallyplacedat each station: (1) one samplingat l-or-*min intervals.fora total time of 24 min or 2 the other samplingat 3&&n intervals for a total tinmeof 12 hr. BasicaU.y,the sane type of instrumentswere wed to sample fallout on the surfacelad and surfacewater shots. anism and a housing (Figs.2*1-2*?). Xach sector containeda triangular tray 3 3/7 in, x 10 in., ancl3/4 in. deep. One tray at a time was exposedto fallout throqh an openingof equal size in the top Cover. The wide end of each tray held four glass countingcups (1 in. in

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diameterand 5/l5 in. high), positionedin a quadralateralabout 2a in. on a side. The cups were coatedon the insidewith siliconegrease to producea tacky surface. This tacb surfaceheld almost all particleswhich came in contactwith it; rainwatercollectedduring the samplingintervalwould not wash particlesfrom the tacky surfaceunless the particlesthemselveswere soluble. An 8-o% jar was fastened beneathan openingin the bottom of 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 min,thecoverdoor opened and the first tray roved into samplingposition. Succeedingtrays moved into positionunder the cover openingat set time intervalsuntil the cyclewas completed; (Fig. 2.6)* The door then closedand the nachineshut itself off. At the time of the detonationan external timing signal actuated the clockwhich had been pre-setfor a short time delay before the door opened (Fig. 2.S). At the end of this delay xrdcroswitch clockwas tripped,allowingthe currentto flow throughthe dri ng motor which in -turnrotatedthe spider;the door opened and tray 1 roved into samplingposition. spiderrim was nc longer closedby one of the cams on the spider, microswitchC2 opened. 'ihisrevved the currentfrom the clock coil and reset the clock. The drivingmotor continuedto run until the cam to the driv%g motor was broken and the z closed,the currentpath mo or stayedoff until the clock finisbd another cycle. Succeedingtrays roved into nosition under the cover openingat set tim3 intervalsuntil the sampling cycle At the tinm of detonationa spring cam was resting on a microtrical latchingrelay R3. As the cycle progressed,the spring cam rode over the microswitch,S5, completinga circuitthroughR3, which pras thrown and latched. After the last tray was in samplingpositionand the door closed,the spring cam again rode over S4, breakingthe circuits and stoppingthe instrument. Push-buttonswitch,Sl, was used as a reset srritchso that the operatorcould sas_Uy reset the entire instrumentby one simple operation. Toggle switch s2 was mountedtier the clockand was used to preset the @ock. This snitchremainedclosedduring the entire operation. Resiitor ~1 controlledthe drivingmotor speed to keep the trays from overshootingtheir position. Variablel-ohm resistorsand also lengths of nichromewire were used. Where wire timing signalswere availableat a station,a minus used to actuatethe IFC. There no wire timing signalswere available at a station,an EXNG Nark III or Mark IV battery-poweredbluebox was used to actuate the IFC. I'7iretiming signalswre initiallyused,

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wsre not always reliable. However, towardthe end of this operation. blueboxsignalswere used where feasible,becauseof the satisfactory timing signal cams from the Project2&a nondirsctional,photoelectric, At the Bikini land stations,the IFC and ite batteries.were to Q&man Navy life floats (Fig. 2.10). These floatswere mooredto floatsidenticalto thoseused by Project2.5b* The Reject 2.5a floatsin turn were tied to mooringbuoys furnishedby Holmes and batteryboxes were dug into the ground flush with the surface(Fig. This projectparticipatedin Shots 1, 2, 3, and 4 at Bikini Atoll and in Shot 6 at EniwetokAtoll. It had been originallyintended to participatein Shot 5. However,water wave damage to the stationsfrom Shot 4 made participationin Shot 5 impractical. Generally,IFCts were placed in groups of two at Bikini locations,arrlsinglyat the Bikini raft and Eniwetokstations. Where two IFC's were on an island or raft station,one was set to sample for 12 hr at 30~min intervals and the other was set to samplefor either24 sampleswere collectedfor Project2,6b to determinethe degreewhich the base surgawas contributingto the residualcontaminationpattern. The 5-minintervalinstrumentsdocumentedthe early fallout and the 30-xrdnintervalinstrumentsdocumentedthe falloutfor the maximum length of time possiblewith this instrument..Where one IFC was locatedst a stationor raft, it was set to sampleat 30-&n intervals The stationlocations and timing intervalsare listed in Tables 2.1, 2.2, and 2.3 and shown in Figs. 2.12 and 2.16. ately followingthis event,the project'smain base of operationsat Tare was razed by fire end most spare parts, atiliary equipmnt, and operationalsupplieswere lost. Ths long delay before Shots 2, 4, and chargedin the hot weather,reqtirlngfrequenttrips to the stations Heavy seas in the Bikini Lagoon causedthe cancellationof the Bikini raft stationpagram. Ths rafts broke away fram their moorings with distressingfrequency. Locatingand mooringthe rafts in

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the lagoon proved to be dangerousto perscnnel. Salt spray and water made maintenanceof electricalequipmenton the rafts difficult. Both elactricaland movingmechanicalparts ccrrodedqtickzy. Only a minorityof projectpersornelwere able to work at the raft stations withoutbecodng seasick; Only two of the originalnine raft stations sampledsuccessfullyduring Shot 1. All raft ir&rumontationrecoverable after Shot 1 was removedfrom the rafts and used at land stations Since no saqles plpereobtainedfrom predictedbase surge region of any CASTLEshot, none of the desiredinformationabout the characbase surge phenomenawas obtained. RECOVERYAND SHIPMENI OF SAMPLES Recomry was carriedout on the fourth, fifth, and ninth day Shot 1, the first day after Shot 2, the first and secondday used a D-passenger helicopterto recover samplesfrom the land stations. A second two-man team used an LCMto recover samples from the raft stationsafter Shot 1. The recoveryteams removedthe spider assemblies from the IFCls, placed them in dust-tightboxes, All locationsavailablefor packagingsampleswere so-hat windy and usuallyIn contaminatedareas* Packingwas done onanopan barge near Nan after Shot 1, in a Tare tent after Snot 2, in a Nan tent after Shot 3, on Oboe, in the rear of a closed truck turned on its side after Shot 4, and in a tent at Elmer after Shot 6, The jars were removedfromthe trays and capped. ‘she trays were surveyed where possible, and a few samples selected for decay measurements at the Project 2.6b Elmar laboratory. mast10 nsnap-on~ caps were put on the glass cups, and the trays were sealed with aluminumfoil. The trays and jars were returned to Army Chemical Center, Maryland by a special sample return plane which usually left Eciwetok one or two days after recovery was aompletade

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PLg . 2.2 Interior of the IFC, Shming the l&or and Gear bducer

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Fig. 2.12 Station Layout for Shot I OS Yin xntuval bllwtorr Fig, 2.13 Station-out for Shot 2

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0 S Yin Intrrvol Coltrctorr Pig. 2.16 StationIaput for Shot 3 Flg. 23 station lqout for shot 4

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NORTH PACIFIC OCEAN ENI WETOK ATOLL ...0S Yin Inhrvol Collrotorr Fig. 2.16 statian bycmt fur Shot 6

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eventj"b" the IFC did not operatebecauseof interrvllfailure;W the IFC not operatethroughthe entirecycle;"dn the IFC did not operatebecauseofdid

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event;"b" the IFC did not operatebecauseof internalfailure;99 the IFC did not operatethroughthe entirecycle;"d* did not operatebecauseof water-wave

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Raft floor and?FC destroyedby Mast. (1 min interval) Base Surge shot. Missingafter shot. (30 min Rot set up because 2.5a triggerraft was tissingbefore shot. (30 tin Lost beforeshot. (30 &I interval), Two IFc's on raft. Lost before shot4 (1 and 30 min intervals). Base sqe Did not operate.(30 min interval). Lost beforeshot. (30 ndn interval).

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Blast damagedthe batteryboxes, Blast damagedthe batteryboxes, Water ware upset eqtipnt. Bluehoxwas not triggeredby Locatednear reef SW of Alice.

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Documentationof fallout included:(l)surveyingof fallout extrapolatingth8 beta activityresultsto …