Dissolving of Twenty Day Metal at Hanford

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Ow ton of ir radi c tef uranium with fifteen days coolinF was dissolved from a two ton batch loaded intoa clean dissolver on December 2, ?.9LS, Calc ul ded. a m o u t s of activity evolved here GO00 curies of 14.31 an& 7300 curies of Xe-U3; measured values were higher thm this by a factor of 2to 3. & eli d nary ca’lcxl a t i o n 8 of the hazard were Illede by the method of 6. G. Sut‘5on and attempts made t o check these values by reac3ngs on fixed and mobile instruments, The meteorological con6itions during the actual hour8 of d is sol ~ n g ’ nere uns+.ablt with the winC veering from 3 southerly direction a t the start t o a northerly direction aboxt helr-my through t h e run. Rawinsonde readings a t Richland during the run indicated as hallo ~surface inversion with an unstable condition daft. It is poatulated that much of the dilution occurred above the inversion, Reedings as high as 2 x 10.4 uc/l of 1431 and 2000 t o 3000 c/m on portable Geiger counters were obt25nod ri thin a radius of 4to5 miles from the stack, Significant readings cppcarcd i n the Richland - Pasco - Eenton City area about no0 of Dee mber 3. filters at Spokane on Dccembcz 3 and Deccmtcr 5 , 1949. hdi cate d peak act iv ltl as In the morning a t Ritsville and between Richland m d Considerable deposition occurred particularly Cl03e t o the stacks, vegetation readings, above the permanent tolerance value of 9 m u c h occurred mer a region extending frob Tho Dalles, Oregon, t o Spokane, and from Yaldma t o the Blue Mountains. The rate of deposition in water was estinated at2x Id; vegetation decayed t o background with an eight Gay half-Ufe. thosc found In other plants. Animls collected from the region Indicated that 8peCime~from within the yroject boundary received th poi dima v afi on vqJing Zstinated maximum concentrations vcre on the order of IOo9 t o 10I& ucfi of 1-1-31, Queetionablie positive raadih@s.were obtaixkd on Aircraft measurenents mado i n the dlrection of Spokane on December 3, 1949, It l a postulated that -the peak closeat t o the project vas due t o 1-331 lkposrtrer of clesn potted plants in the area gave results compsrable t o from tolerance t o 80 times tolerance daily.

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DISSOLITNC CF TI?ENTY DAY MFTAL AT HANFORD The Health Instrument Divisions were interested primarily in obtaining monitoring reeultrr tome that no one was overexposed tothe active fumes, and aecondarify in the travel -of-the activity and depoeftion-on_fhe,voeetation, 5ntroduction to the report, is a map showing fhe location of the more prominent

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8ad seeing fhat t h e hrmes -em liberated safely, An outline of this planning $8 Upon ree eh bg this information, Qach group participatfng started more detailed obtaining as mch information 8s possible from the operation holm aiaoo mu& of tho nork dono a t this time aided considorably ia Inter - TAW tb3.n mmmt of activity being roleased, good dilution of the fumes before ihg came fo tho ground i n the areas wore required fo a ~ o i dgross contamination of tiha build hp and possible exposure of por~omu~l.Criteria decided upon for weather (1). & Lmerted vertical temperature gradient extending from the ground fo 8-1 fnmdred feet above. ThLr otipulotlon necessitated sche duh g the run durkrg =iM-time, as it is 0- then that inversion conditions a t I I ~ O ~ are fie- [2). 100 rain, fog, low cloudineas, or &er frrctor which miat pretrenf t h e 0 (3). w#t fo modemto d s d Rpoeda 1 5 mph a t the 200 ft. love1 was decided

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feet hi@ Rattlesnake Mountain t o t h e snut'r of the mea. (5). Conditions where@ the bulk of the stack effluent would stsy aloft. A dilu-bion factor of l5OO:l was decidad upon a3 t h e lowest penni68ible factor. A r e v i e w of date from the past several years at the Hw Ideteorologp Station showed *a+, during n i & t hours at this season of the year the "aloft" condition p ~ - vailed 76%of tbe time, and that the sky coverage averaged 6.7 on a scale of 10. Hourly nind speeds between 0300 and 1200 averaged from A-6 q h at tbe7 feet level to 10-11 lnph a t the 4OG foot level. The prevailing direction was northuest. A de rate fnversion usually overlies the area atni & t , forming near sunset and tesminating about one-half hour after sunrise. sad the probability of its occuTence during sny particular 24 hour period ia dm8 Normally, precipitation is infrequent The above statistics indicate tSat the chance of finding favorable ~ t ~ orchg - ical condi%ionsfor t h e dissolution on q particular date might be good. Hommr, the mntb of Nawmker, 1949, was plagued nith inclement weather which included two periods of recurrent storms w i t h attendant wind and rain, interspersed by a lO-dey 8tagMnt period during which ceillnga wre continually lor and fog was present on nn a m p of nearly 10 hours each day. This inclement weather necessitated postpanennxzt of the n m for one ne&. I On fhe morning o f December 1, the United State8 Welrfher Bureau in a apec i al forma& to f h i a plant, predicted that the end of the current rories of fmqwnt simnu5 r a a in sight, rrad that conditions favorable for the operation could be expected * Saturday nigh%, December 3. The d h o l v e r mr t€ien loaded bo tbat opera= tionS d d begin Pridap d@t,December 2, if condition8 were favorable. Tht, W Didsion, in charge of the actual dissolvfng, elected to uae the upare dissolver 3x1 the R l ? plant (200 Vest Area) 10 that the "heel" reuultlne h p m the ,--! dbrolutlon of only a portion of the metal cmgsd, could bs stored h the U s - solver for an sddlticmal cooling perid. Twa ton8 of metal pushed on Kowmbsr 17,,

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uem loaded i n t o a clean dissolver on December 1, 194?, and the jackets dissolved OE *&e 12-8 shift on Deccmbcr 2, 1949. Tho actual length of the dissolving time taLe uf metal per chargs on tap of a one ton heel. An estimate of 12-16 hours f o r t h e dissolution of one ton ms made. The amaunts of 1-131 and Xc-123 in the metal after 16 days cooling wre cs;lmted at 6150 end 6370 curies per ton roapectively. Assuming thtlt 5% of t h e io&e(*) remab in the dissolver and that there iso 30%increase over the averago in t;ho amount8 of fission product; in tke outer portion of the slug, the dissolution of one ton nould l i b o x t o 4000 curies of I-l-31 and 7900 Curies of Xc-133. S a c 0 the off-gas scrubbers nore not opcrsted, all of this activity would be diadhrcrged fmm the stack. -Th6 rate of discharge vas ostimcted f r o m thmo evolution curpos moesurcid in - 1947 bp the 8. I. Divisions. These curves indicated tlmt rifh an ei@t hour d b - solving period the Xc-133 reaches a nvudmwn inbl / Z houre and the 1-131 reaches a m d m m in 3-4 hours. Extrapolation of these curves to a 16 hour di8solving (Fig.2) Andieated a xenon peak a t about throe hours and an io-o peak a t about amen hour8 aft= the statt. me rncuinnau rate of omission waa estimated a t 0 . a curiee/sec for Xo-I33 snd 0.U d e s / s e c for X-131. These values wuld mount to about 28 UC/Z of ~0-133and 10 uc/l of 1-131 in t b o stack on t h e bas18 a" an e now a i The Strrt mr planned f o r 2000 on Docember 2 a8 a compromise between the Bir Fomeccr8den- to s t a r t a t 01001036(! on Decomber 3 80 that the mcxbuum would occw w libouf baybook, snd fbe opO~fiOn*SnQOd b 8- Q 8 IO- after SUndom 88 p d b b no that t h e buQ of the activity wuld bo liberated before fh8 inversion bmke tha N next moraing. With the start at20 ~ 3 ,t h o ruudanm 18-133 1-131 actfvity would o c w abaut hours before surup to olimlnata most of the acfivify. actid* would occur abut

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Extra neather forecosting and observation stations were s e t up by the Air T?t.her service t.0 augment existing stations in order to obtain sufficient data 23:- Torecasting tbe movmtent of the cloud and to com late the ed sting conditions with the activity pattern found. Reports of forecasting and obsorvation stations over the Northmst were utilized to get B clear picture of the weather for weeks before the test, mobfie Rawinsonde station and two pibal units sere mvod into the VicWW of the Banford Fmjeet fora more detailed analysis, '&o Richland Airport and one each of the pi bal etations a t Washtucna end bses fake. The Rawinsonde unit was placed a t 5, 6). The basic equation for these caldstiaola ist

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sum of tho s t & Uty of the Rtmosphore. 1 = t h e heiw of tho stack 5n meters. as he wed tbm for tc sts in Podon, England. This is one of the weak poi0 in auch a cttlculation since the conditions a t Banford as8 undoubtedly different with rcgard t g gustbeas, etc. .Howover, it rpas folt that est bat ions this mothod rm;rld be du abl c in foreseeing hazards snd b interpreting re0d.t~. Tho cwfValue8 ofthe coefficients Cy, Cc and n were abstracted from pcpora of SuttOnts

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2001 above the gFouad a t distances up to 200 miles. These coccentrations are the maximurn expected along the ax58 of the cloud if It i s assumed that uniform meteomlogical conditione end flatter re in are encountered throu@out the entire path of t h e cloud. Two values a r e given for each distence: (1) the coefficient of the t be dud speed in meters/sec, and 2is concentration in ucfi; and (2) the actual concentration f o r an erniesion rete of 0.05 curiea/aec (cloee t o the average expected f o r Z-Ul) and a wind ped of 11 mph. Fim4 presents eLll estate of the vidth of fhe cloud s t VarioUS di8tanCe8 If it b assumed that the wind I s steady in-one direction. In this cue the cloud w i d t h is defined as the distance betwean the tw polnts on the elttremitiee that hwe a concentration one-tenth of the peak concentration. The maxbmm rctivify expected a t the ground i s pretteated in Figure 5 undor the mma Eonditiona as for the air concentrations. Tbo ground pattern expected for a stsaw moderate inversion condition with a wind sped of 11 mph i8 glven i n Figure 6. FLred bstnrments WBCB located at strrte&c spots where power was available on .the zmsrPr&n. The location o f monitoring instruments during the run ie &yen in Figare 7. All of t h e counting rats metors and nust o f the dr scrubberr were put out specially for the operation and later remow. ' Field creua to {I). Two mea in four &eel drive equipment wre to attempt to locate the point out t h e follorlag jobs were plsnaed: of msximm air concantration and make traverres acros~sthe cloud W d n g reedings

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balloon t o several hundred feet so thct traverses of the cloud a t the axis could ( 3 ) . One man was t o t r a v e l from the intersection of routes 42, and 2s to several niles above Hanford reading detnchable chmbers every mile and tdcfng smll scrubber cad portable GM readings, (4). Two men were to travel fron Pasco t o Connell withR recording GhI counter ada 1-112 CFX air scrubbar operatod from a nobile gonerator, (5). Gno nan was to check a l l instrunents during the run and t c taka small scrubber samples on the reservation. In order t o keep current with activities in A~~ field during ths tine of evoluallowed the use of three telephones end was conveniently located t o XGidB, the patrol radio station, Thus it mes possible t o obtain reports froin tho field cars by radio, from various sur r ogg mps by telephone, and meteorological data from the special units set up by the Air Forces by telephone, This dso allowed the use of the plotting mom facilities in conditions appr ohm ting those o f an actual emergency and mas very valuable 5n gaiiiing information on techniques. The plotting morn was manned by Health Instrument Personnel from 1900 on 12/2 *-- t o 1000 on U/3 and by an A i r Forces representative from 0100 on 1 2 / 3 t o 1000 .on

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Equimnemt and Procedures fn en oral, ~1 brief discussion of the cquipment and procedures used fora particular reading or series of read he is included in the section pre son th g the data, Thi8 section o f the report is lntendtld to describe those items nhich %are used general3y throu&out t h o t7u1 and pocethms nfiich were used in t h e mdy-

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rip d to “scrub* the iodine from the air pe.ssing through if. %bmu&t he liquid from the bottom and splattered the caustic solution on tho filter. Both the solution and the filters were analyzed for iodine content. Diff id Q mas encountered When the systbm was in operation. It WaE founc! that bg t alt bg the n k for the scrubbcr fron the exhaust end of the conductivlty tube, the head of solution roduced the airflow through t h e conductivity tuba t o su& a low value that much of the conductivity sensitivity was lost, and the scrubber had to bo &connocfed duriag the fligbt ln order thet t h o readings taken from the conductivity meter would ’be reliable. A standard General Electric Leak Detector was put aboard and oqui-d rrith - 8 recorder. The probe was t3ped to a whdoi w i t & tho t i p extending throub the dafortable Gaigcr Counters wed far fiold mas,curemonts were mostly the Vicforeen %del #3638 88 l ‘ i s t e d on pago S a - 2 5 of tho AEC Radiation Instnwent Catalog

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the ground. The counter pulse modulated 8 nationalHR0 receiver which detected the carrier; the detected pulses sere recorded on a Hallicrafters Model % Tbe countfng rate meters apottee around the area were General R s a o Unit6 feeding into Esterline-Angus Recorders Thay …