Letter to Commander, JTF7, Et Al, Subject: Radiological Surveys of Several Marshall Island Atolls

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1. Attachedherewlth for your inforamtim and rehnti m are copleu of radiological surveys made on certd,n Marshall IslandAtolls. The surveys were conduotedaa a result of contaminationdepositedon the affeotedatolls half nautioalmiles scjuthweetof Naim, Bikini Atoll. BRAVOShot tb was t 2. Whter and aoll samplm were ahi~ to the Heal#hand SafetyIaborfFOR THE COKMANDEZ: BEST COPY AVAUJN3LE -.- Cm 7.3 - Copy 32 Qliefof staff 1. Report on Soil and L%ter Sampling 2. Report on Soil and “JaterSampling @Mo 3. i%d. Surveyof Downwind Atolls Contaminated

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and AIXDK Atolls, JMO Mand and MEJXT Islandin the E&em hshalls between measuring level of gamma radlatIon presentat those placesIn c~eotlon with BRAVO. The miss~ consisting of the underalgnedand a &rsh@me interpreter, Ian Iakapan,enharkedon the US BEWAW (DDE@9) at Kwa$dein, visitedtk four sitesand returnedto Bll&i, where the reminder of the ttip ,toWwetok.qs POXV formed by PEW ‘Rmre followsa detaileddisousslonof the flt@lngsat eaeh ~ocaas LIKIEPATOLL. The samples were taken on LikiepIsland,whiohhad the Poor lightat th end of the day and numrous coral headqnecea&t@ed anoherimg about 4 miles from IAkiepIsland. l!ripin was awls by whalsboa~‘b foq MO-. A inter samplema taken from a large cisternfed from th x of the Catholioreotory, and earth sampleswere taken from randomsp@ about isI&d readingwere noted on clothingor bare feet of individual. AQoordbg b’+ Island. TMS locationwas reachedat UOO 14,6 Maroh 1954. R heavy surf on three sides. Therebeingno plaoefor Ia@ing a tialeboat,perxaac: and equipuentwere transferredfrom the whalsboatto the reef by a one mm zubber raft. The undersignedtransferzwdhimselfby miming. The islandprovedto be uninhaMted, and report+ is a sea turtlepreserve. Turtlehuntersereoted severalhouses,a rain brrel of which provideda water sample. Earth GKUI@8U were gatheredat ranti from open meas, Including me of beach sand above the high tide mark. The party was led straightacrossthe islandand back to the M

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higher male showeda lower reading. lkwoh 1954, md s ly moved to an anohorage off Ailuk Island, the most heatily populatod. The lagocn has not beon swept, and numerous coral hinds and pinnaol.os prtided considerabb hasardto hip nmmment. The landing~rty movedmhcm by whaleboatwithotidfficulty, and again obtainedinter samplssfrom the xat pron&- ent clstmrnand soil samplesfrom mndom unshelteredspots. Redngs with the MlC-j r=q of 7 =/’&, howevor, on a difforontmale a readingof 12 or 4 mr~ was obtained. The U-5 reading is probablynearestcorrect. No dgnifkmt varlatiom were detcctodon bare feet or clothingof Individuals.Samp&s and readingswere d. MEJIT Island. This sir@s Cod islandis also surrounded~ a roof, ho surf. The isti was foundto bo homily popu&ted In view of its sise,tho fieldinstruumts of tho type used arc M@@ Unsatitiactory. Qlo U-5 and thrm AN@DR27 B tistruments all showed wido~ variant readings on differeotmales, and variedamng eaoh other when exposedto the same radiatAm= An A@DR ~14 Pmmd oompleh~ usekss nut holdingto sero oven after an hoursmm-up, and also showingwidelyvarknt readingson diffarentmales. 3* IuKmQmDla~S. biding parties In islands such as ~ and WIT should with loss dangerof the boat being stow k. shl~ as~ed to suoh miseions shoulddraw suoh oqui~t priorto dqmrture. 4. Tho successfulaocomplishmcmtof the missionms greatlyfacilitatedby tho titarestand enthusiam of the Cmmnding Officerof the USS I@&Ui!Y,(XR L. Hto the misaim, howovgr,the my wl~b~ suggotij.ms and assietme h mluticns

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1954 for the purposoof obtainingearthand drinkingwater samples, and of masuFing gamm cay doso mtoa, and a3so ~hookod tho radiokxl c~tion of tho S.S. ROQJE on ita arriti at Mjuro 7 Umh 19540 2. Tho first four atollaworo viaitodby Mmhalloao $mtorprotorTala@xi C-47. Erikub might havo boon omitted sinoo it was not Inhabited,Ming pmporty unknom untilaftmr tho fit. ) % At - aton, only WI principal inhabitedidand was d.sited. At eaoh vidtod islandan effortma mado to aomposoa roprosontativesoilavorago by collmting into a ahglo oontainoramoral 6amplo8,oaoh apprdmtoly me aquar’ foot of area and one inoh depth. Water aamplosworo collnctodfrom tho princi~ soumos currentlyin uao. Tho gamnm doso ratesaro avoragasfor tho inhabited kby Major R. D. Oroa and tho titorj It ma origimlly plannedto perform’* T r $xintly, and when it beoamo adviaablo to soparatoand mumy difforontatolls, no tim remind for diaouati of detailsof toohniquoa. 5. --ray doeo rates on .Mbtjoand on Erihb am -ch tho amrago of =-5 inoporativo *on tho rubber Wo raft WAS awampodby surf @l”tho f$ratatttiy@to rangoaro of very chabiousr+abilityg 6. Tho following tabuhtion ‘mumarizoatho atull aurvoy. S tu Sou, W ia AT(U ISLAND DATE TIMB SAMPLENO MR/kR & SAMPUNG m path to beach. NO ti~. ants, no water supplyfound.

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turo,M on open deck,.5-8 in sleeping qudxm on qbr. dock, _30 on rope and down as som as convenient.He was told that the aot%vityxmld not hurt .anyenc, but th+ $t was undesirableto have it aroundlongerthan necessary. - ~i=e h such operationsis very Mmitod, but from his cm obsorvaticnsplus of risk is imolvod. 9. Especially notablowas tho very cooporativoattitudoof the Navy porsonw

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squaro foot to a depthof ono inoh. The nunborand locationsof tho samplm wore solcctodto roprosont,as well as couldbc @dgod, an averageof the arms used unusuallyshadedor undwdod by trees mm avoidod. ~o largo apcbblm~ in tho W&or samplm woro soloctodaocordingto tho principalsourooin currentus{>.

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boat parttos,and it =S only throughhis personaldirootionand participation that it was poesibb to carry out the sm@ boat surwys under oxtzwm~ difficu” caxlitiona. Smoe most at tlm lagoonrotorsworo not navigabloby a DDE, it was nocamary to mako long boat trips In high seas and land m trickycoral X’O@JO Tho HUiVO Shot contamlnatoda nudxr of atollsin gom~ oaatwafi subjootdotaibd radiologicalsurveyof the atollsto tho oastmrd Of - c. Tlm ostimaticn of MO realdual radiation offoota of Iargc-

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MoO Twopartiesin mill boats mrmvd Uving aroaa 1130 Two partiesin amll boats groooododfrom tho IXX: whioh =s stationod outsido Utirik Atoll II@ survqmd Utirilcand Aon Islands,tho main islands of tho Atolls 1700 Ono party in a qall boat Ian@”-* tho outer llm Two partieain sglallboats proooodoq statlmod) and tho otlmr@portant islandsof tho Atol Orn islmds of ~Obp Atolland om partyxbchock)d tho llvingareas on ~olap bland and ostabliuh6d a roforonoo looation for futurodooayrnoasuro@nta. Surwy team arrived Riiwotok Atoll via DDEo IWiac sot AN/FDk39was sclcotodas tho instxummt to bo used in the zerovariationbtwoon inatrumcnta- any scalo. Upon cross chockingthrco of Thoso mrvoy rotorsworo subjectto prolonged and oontinualroughhandling. With cno acooption,all efficientlyfor tho durationof tho oporaticm On tho uso underadvorso condfi

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that CM surreymotor couldnot bo proporlymm adjusted. Tb four rodning AN/PDR-39,stilloporatodofficiontlyand soomd to be in good working ordor, of each atollaro plottodIn Figures1 through5. All moasuromntsworo fmdo at masuromontsmade with tho Mrum& n- to a contadmtod Surface. appoarcdte have slightlyI.oworavorago dose rates than &o romahdor of tlm island. This oan perhapsbo ascribedto differentgocmotryof tho contamination and to dightly groatorpcnotrationinto tho 100sogravelin tho nativovillagcsv. Tho &so ratesinsidotho natim huts appoarodto & almosttho sam as the doso rato outSide. Tho doso rato in tho mid~o of the militarybarracks,tonts$ and on tho windwardal&s of the islandsappaumd to bo sMghtly abovoaveragoconTYPICALREADINGSIN RCNGELAPVIIZME -8 MARCH Locatim Dose Rato (m/k) Near central cistern 300 Near northom cistern 350

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In orderto etite the rate of decaybetween8 and 11 March,the following radSaticnnwasurementswere taken on three days on Ron@ap Island: Southern most cistcm 220 mr/br 145 mrb Water samplesmre colloctedfmm the mtcr suppliesof au $ahabited areas. About two quartsof water were transferredto a pol@hbno bottb at each alto. Thesowill bo turned ovor to tho Now York Oporaticmsoffice,AEC fSoil samplaamm coticted at all inhabitedarms and aZso et sovcra? Unlnhatdtedislands. In colhoting tho soil eamplosa ono foot by cad foot sqww was matim the groundand soil to about ono inch of de~h was romovw fzwn the squareand transferredto a cardboard container. Tho pzdfmry SMIPbS will k tuned over to the Now York OperationOffice,m, for anal@s, and Wed in Tablo 3 are the aamplastalmnwith tho dose rato moasurod .. at waist heightat tho location ~ero tlmy mm talen.

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Utirik (cistern at south of In additia to the above,a aamplaof foilagewaa takenat th windward side of Bikar Island. The radiationfield was 180 mr/k cm 9 M 1%4 80 Conclusims and ~C~ datlonq a. The mdiological surveyprovedthat a largefield surfacedetor.- tion can produceextremly serious radiological contamination ever a dlstancc mom than M MUSS dmnwind and importantccntambtion about 250 miles domr sawmtwt north of Rcngelapmd RongerilcAtollsand probaMy not far from n k~ betwem Bikiniand Bikar. the draw SOtiheaattip of the ato~, the cataminatim was aboutten -s greaterat the north side of the atoll,twentymiles away. d. TIM cmtadnetti decreasedby a factorof about @t ovorthe damwind distance of 50 miles between Ran@ap and RongerilCO f. The AN/lDI&39 proved to be a very diafactory instrument for field surrey work under rigorous etvdronmental conditdmns. =.factorymethod of conductinga broad mliological summy of the type #u* complete& Future surveys should considerusingvesselsca~ble of entertig mom of the atollsand of handlinga hdic opterand severalsma~ boats. 3. Rid. Survey Bihr h hi. Survey Rongerik 5. Rid. Survey Ailinginae 6. Summry of Rad. Survey