Interim Off-Site Report of the Johnnie Boy Event (Operation Dominic II) July 11, 1962

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JOHNNIE BOY EVENT OPERATION OOMINIC II OFF-SITE RADIOLOGICAL SAFETY ORGANIZATION 5!4£1BEST AVAILABLE COPYBEST AVAILABLE COPY

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TABLE OF CONTENTS LIST OF FIGURES Road 3 Remon i tored Figure 5 . Monito~ Readings a t Cedar Pass, 8.8 mi les Nest of Cedar Pass, Rev ie l le Mill , and 14BEST AVAILABLE COPYBEST AVAILABLE COPY

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LIST OF TABLES Charc•Jal Cartridge Isotopic Results Ratio of Activity to ~aximum Permi ssible 30BEST AVAILABLE COPYBEST AVAILABLE COPY

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Of~- Site Radiological Safe t y Organi z1 tion The JOHNNIE BOY event was conduc ted as a sur f ace shot in Area 18 at 0945 hours on July 11 , 1962 ; by the Department of Defense, According to the AEC-PHS Memorandum 0 f Unders tanding , the Publi~ Health Serv ice Off-Site Radio l ogi~a l Safety Organizatian perfarmed a miss i on of off-site radiation surveillanc e during this event. of a radi ~active c l o ud whi ~h moved north from the test site. This c loud split into two portions : the lower portion traveled s ligh tly wes t of north to the area ,:if Highway 6 between Tonopah and Warm Springs, then traveled east o f no r t h 1 after ass uming a width ~f 25-30 miles ; the higher portion, above 11 , 000 feet Mean Sea Level , traveled east of north. The higher portion produced only a 3mall fraction of the fall~ut from this event within sever al hundred miles of Ground Zero. The highest reading taken by ground monitoring in a populated lo cation was 3 , 0 mr/ hr at Rattlesnake Maintenance Station, 92 mi l es f r om Ground Zero on a bea~ing of four degrees. The highest reading reco rded on a recording radiat i on monitor ~perated at a populated location was 3,8 mr/hr at Twin Springs, seventy-five miles from Ground Zero on a bearing of four degrees. The highest gross beta activity detected on a glass fiber air filter from a populated locati~n was at Twin Spring E with 23,000 • I I I • METHODS AND EQUIPMENT Two Air Force aircraft, a WB-50 and a U3- A, manned by Air Force crews , were supplied to t he PHS to conduc t aerial radiation surveys during this event. The aerial monitors with a range of 2 - 2 , 000 mr/ hr, and additional survey instruments as used for ground ~onitoring •

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All field uni:s, includ:n5 the airc raf: , were equippea with For the ~ap of roads monitored and c l oud passage , 5ee Figure 1 . For t ~e map o f roads remonitored and residual activity , see Figure 2 . for recording radiation monitor locati ons, locati~ns in the off- si~e area during this event. The air samplers are Staplex and General Metal .Yorks high volume air samplers using 8 " x 10 ' glaaa fiber filters. Fourteen of the stations were alao equi pped with MSA a c tivated chargaseous fission products. Flow rates are about 50 cfm for · he glass fioe r filter alo ne and 25 cfc with the additional char coa l cartridge in place. See Figure 3 for the air sa~pling station locations. Glass fiber filter3 were counted for gross beta a ctivi ty in the proportional range on Nuclear-Chicago Model 192-A ultrascalers with Eberli ne Model AC- 4 fission product backgr~und levels were counted several times w1thin ~~ree to fi ve days to study decay characteristics. All charcoal cartriages a nd any glass fiber filters with gros s beta ac t i vi ty significantly above bac~ground levels were counted f or specific ga.::ima ?.•i:!.tticg isotopes on a RIDL 400-chancel spectr ometer , using a steel 9hidlrl with a NaI(Tl) crystal with a cs 137 peak resolution of eight percent, -2-BEST AVAILABLE COPYBEST AVAILABLE COPY

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The ,VB- 50 aircraft t ra .::;<ed tne c l oud f r om 0945 ho 1.1rs until 1,105 hours, N0 rea d i ng s were rake:1 withi!l t he cloud s o as to avoid a i rcra ft con. .... a~ination. At 1005 hour5 the r ead i ng a bove t he we st edge of the cloud wa s 5 ~r / hr a t 16 ,000 feet .MSL . Th etop of thec loud was e s timated to be at l3 000 feet MSL , wi t h -;:he cloud f our mi l es long, t wo mi l es ·.1, ide, and novir..g on .1 beari ng of fi v e degrees f r on Gr ound Zero . At 1012 hours t he lea ding edge of t he Lake . rhe t op ofthe ~l oud was a t 16 ,000 feet MSL at 1014 hour3 and t he reading 1 , 000 feet above the cloud a t th isti me was 500 mr / hr, At 1 0 24 hours , a n e a .at to we st pa s s was made t en mile s south o f Kawi ch Dry Lake , 1000-2000 feet above t he cl oud, with a maximum r e a d ing encountered of 1000 mr/ hr. The l e ading e dge o f the c l oud was a t Kawich Dry Lake at 1040 hours, and t he clo 1..1d width was e stima t ed at f iftee n mi les. The cloud l e ng t h was estimated at ten miles , extend ing f r om twenty t o thirty miles north of Gr ound Zer oat 1045 hours . At 1125 h ours a pass from 3even miles sou t hwest of Reed to two miles northwes~ of Reed at 18 , 000 feet MSL , 500 f e et abov e the cloud, showed a maximum readi ng o f 100 mr /hr. At 1140 hours a pass was made ove r t he port i on o f the c loud t hat we n-cover Gold Flat Dry Lake with only ba ckground r ead ings encoun tered . The high por t i on of the cloud was aga in foll owed t o the nor th. At 1402 nours a r e ad i ng of 0 . 5 mr/hr was found ten mile s northeast of Lockes ovsr Highway 6, The cloud tracking miss i on o f t h e WB- 50 was termina t ed at 1 405 hours . Table 1 contains the ~ompl ete aerial monito r i ng result soft he WB- 50 , Al l readings above are gross gamma mr / hr as measured inside t he a1r~r a f t and are not correct e d for the a i r craft a ttenuatio n of 3 0- 50%. The U3-A air cra ft t r acked t he c l o ud f rom 0945 h ours until 15 4 0 hour s . From 1300 hou r s t o 1 445 hours, t he aircraft was at Tonopah re f uel i ng . At 0950 r.our s the top o f the c loud had begun to d r i ft north but the bo t t om wa s still a t Ground Ze ro. By 095 8 h ours t he c loud had begun t o sh ow grea t wind s hear , whi ch was to later split it i nto t wo parts . The cloud wa s e stima ted to be two mile s north o f Gr ound Zero , one and one- half t o two mi les wide , a nd two miles l ong at 1005 h ours with a reading of 5 mr/h r at the l eadi ng edge at 7 500 f ee t MSL, -3-BEST AVAILABLE COPYBEST AVAILABLE COPY

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miles south of the lake. At 1~55 ho~rs the we3t edge wa; d ~e 21u~h of a point two ~ilss west of the west edge of Gold Fla t Dry Lake and the l eading edge was two mile3 south o f the lake, and in the b.)t+ :,m of the upper (. loud with a maxinum read.ng encollntered of At 1135 hours the reading over Gold Flat Dry Lake at 10,000 feet MSL wa::1 220 mr/hr . rhe top of the l?wer portion of the cloud was es~imated at 11 , 000 feet MSL. An average reading of 25 mr/hr was obtair.ed at 1220 hours from Mellan to ten miles east of Mellan at 6500 feet MSL. At 1233 hour s the reading ten miles east of Mellan was 25 :nr/ hr at 8000 feet MSL. Due to low fuel the U3-A aircraft landed at Tonopah at 1300 h~~rs and reB~med the mis~ion at 1445 hours. From 1515 hour s to 1540 hours pa3ses were made from Warm Spring s to Rattlesnake and from just west of wan Springs to Hot Creek Ranch with only ba~kground readings recorded. The ~loud tracking Figure 4 shows the cl?ud position as estimated by the ~?ni~~ring teB.!!l of the U3-A at 1110 hours . All readings above are gross gamma mr/hr as ~easured ins!de the aircraft and are not ~orrected fo r the aircraft a~~enuation of The cloud was firdt detected by ground mon i toring in a p0pula~ed location at at 1247 hou~a . A ::iaxi~um readi~g o f 0.3 mr/hr was takan at 1254 hours, and 9 readings were down to bac kgr ound by 1316 hours. The above readings a r e in excess of the 0,7 "!lr/ hr residual a~tivity from the SEDAN e ·~·ent present at this locatio n on July 11th . Six persons , as well as t he mvnit:>r , we re at At the Tonopah Tes t Rar.ge, fifty-fou r miles from Ground Zero on a bearing ll o f 329 degree3 , a l l readings ware background between 1125 h y_.r3 and 1400 degrees, the cloud was firdt detected at 1405 hourB. Tr.e rr.ax:~•.un reading was 2.0 ~r/hr at 1435-1455 hours . By 1510 hours the readings ~ere down F LBEST AVAILABLE COPYBEST AVAILABLE COPY

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on a bearing of 354 degrse s , until 1435 hours , at wtic.h t1!lle "':he reading was 0.3 mr/hr. Maximum readi:1g taken was 0.8 :nr/ hr at 1445 hour a, and b y 1530 hours t he r eading had dropped t .:> 0. 2 :nr/hr. There were .f:>Ur psr sons in t his area aa well as the ~onit~r. Zero on a bear ing of 345 degrees, at 1430 c 0urs. The r eading a t ~h i 3 time was 0,05 mr/hr , and i t dropped to background at 1445 hours . Th13 r eading was probably the maximum at thi s locatiDn 1 s 1nce the sam!l maximmn r eading at this locati J n as well as the monitor. The reading at Hot Creek Ranc h , ninety-six miles from Ground Zer~ ~n a bearing of 358 degrees, was 0.3 mr/hr at 1549 hours. There were about s ix people in this a rea as well as t he monitor. Zero on a bearing of f our degrees , waa 3.0 mr/hr at 1547 hour g . By 1803 hours t he r eading had dropped to 1.4 mr/hr . There wer~ about five persons in this ar9a aa well as t he l!lOnitors • At Locke3 9 104 miles from Gr?und Zero on a bearing o f s ixteen degrees , a reading of 1.8 mr/hr was taken at 1610 hours. At 1830 caur~ the reading had dropped :o 0 . 2 mr/hr. Th~ above readings at Lockes are in excesa jf the were three people at t hi s l ocati~n although t bia number was vari able sin ce thi s location is also a gas station . The abov e ground monitoring data is a swmnary of all data from po:pulated l ocations that were monitored during this event. All readingB above are net gallI!lla mr/hr taken three feet above the ground. FJr complete ground monitoring data fro~ both populated and non- ~Jpulated areas see Table 3 . See Figure 5 for gra phs of monitoring readings against time at sever al nDn-populated locations; Cedar Pass, 8 , 8 miles wes t of Cedar Pass, and Reveille Mill. Ground remoni toring was cone on the day following the 9Vent 1 n several areas • The only popu lated area s urveyed was f r om the Juncti on of Highways 50 and 93, twenty- s ix mi les southeast of Ely , to Pioche with only backgrour.d encountered . For comp l e te ground remonitoring da t a from both p0p~lated and r.on-populated areas see Table 4 •

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The recorder at Groom Lake, twent y-six miles from Ground Zer :i o n a bearing of se venty- two degre es , showed on ly background activity d ur1 11g th 1 8 event. The re c. )rder a t Diablo , fifty-seven milea from Gro und Zero ona be-aring o f twelve degrees, was operated from 0756 hour s to 1653 hours o~ J~ly 11th. Cl oud arrival wa s shown at 1236 hours with the reading ri,;ing t o a ~aximu.11 of 0.3 mri hr at 1241 hours . The reading dropped to 0.2 ~r/hr at 1245 hours, then rose again to 0 , 3 mr/hr at 1247 hours. The r eading had dr ) pped to 0.1 mr/hr by 1257 hours, and had re turned to background by 1352 ho-..irs. ;he readings above are in excess of the 0.55 mr/hr residual acti'lity of the SEDAN event detected by the recorder. The recorder at Twin Springs, seventy- five miles from Ground Zero on a bearing of four degrees, was operated from 0815 hours , July 6th , to 0745 hours , July 17~h . Cloud arriva l was recorded at 1145 hours, July 11th, with a peak reading of 3.8 mr/hr at 1316 hours . For a graph of the recorder chart at this location The r e corder at Lockes, one hundred and four miles from Ground Zero on a bearing of sixteen degrees, was operated several days before a nd after the event . There were several fluctuations reaching a maximum of 0.35 mr/hr at 1625 hours, J uly 11th, above the residual activity of 0.1 mr/hr from the SEDAN event . Reading3 before this could not be correlated as to time due to power variations at this F. Gross Beta Results Analysis of the glass fiber air filters from populated locations for gross beta activity showed samples with activity above background concentration3 o f radon - thoron daughter products plus long-lived Pacific and Rusaian a c tivity at Diablo, TWin Springs, Warm Springs, and Lockes. Highest activity de~e~:ad at a populated location was at Twin Springs, sevent~-five miles …