Atomic Energy Commission Radiological Safety Criteria During Nuclear Weapons at the Nevada Test Site, April 1957

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The miter i a and procedures se% forth in %ne following paragraphs were established a f t e p full. consideration for protecting tihe health and welfare of the public, both in hme of radiolagPzaP exposure as well as possible hazards, hardships 631- ineonvenfences resulting from disruption of normal act id ties,Criteria are established as guides for the Test Organization fn determining whether any speeieik actions should be taken to protect the public. These criteria are not established with the expectation that the coming tests at the Nevada Test Site actually will result in radiation levels which will be greater tRan heretofore, Rather, they formalize past criteria to give even clearer guides for protecting the public, With improved methods of predicting fallout and with the use of balloons and higher towers for detonating the nuclear deices, it is expected that fallout i n populated areas from future t e s t s at $he Nevada Test Site will be less than the highest mounts which have occ med an the past, Two basic assumptions are made i n this reports as It is the responrsribility of the Df-vision of Biology andMedicine t o establish such criteria for the Atomfc Energy Commission as deemed necessary to protect the health %nd welfare of the general populace from consequences of weapons t e s t e conducted a t $he Nevada Test Sib, b o The operational pPocedmes adopted for meeting mese criteria shall be the PespomibiUty of the Test Hanager, as

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technical guidance of the Division of Biology and Medfchx?. The following criteria do not apply to domestic or wild animals since levels of radiation which would be significant to them would have to be higher than those specified herein,

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were allowed to raafn, One, presumably there might be a health hazard if the personnel Two, there is dwap an element of danger and / o ~ hardship to personnel involved in such cun einergaey measure. It is recognized that esrtcanuatbg ebm st smc es my aeeompzny any situation where eondftfons h die ate evacuation as P mode of action, !be aiee of the communfty, areas and accommodations available f o r the evacueeso weather conditions, means of transportation and routes of evacuatfon, disposition of ambulance caseas protection of the property l e f t behind, and m a n y other factors may enter Snts the decfsfon relative to evacuation, Further, it is recognized that under certain conditions, the evacuation.. of a community might no% only prove rather ineffectual but could result i n more radiation exposure than if the population ~emainedin place unless the situation be adequately evaluated, in advance; each situation can be &que. A blanket svallaestion cannot be made fore are suggested as guides in assessing the possible radiological hazarda; the final decision must be made on the basis of all relevant factors known It the time, They atre intended .e0 apply pr he i pally to relatively large poplatiom since small groups m y be evacuated without equlvcllent potential O w i n g to the necessity of making early measurements and decisions,

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OFFICIAL USE ONLY it is t o be expected that dose-rate rea&ngsp tahn with survey meters, will be the available evidence et the %hes of cma=em0 !!!his necessitates makhg rough approximations fm advance of the effects of wsathernng and of shielding from normdl housing, in reducing =the radiation exposureo "he variable nature of these two pasmetera makes hposs%bPa the establlbahment of a precise Therefore, the faPlwing may be used in making conservative estimates of these effects: a, FOP weathering -- tihe measured gamma dose rates a t thrse feat above the, ground be assumed t o decay ctecordfng t o ( e ) for the first week after a detonation, -Ie3f o r %he second bo For shielding - the aocumulobd dose per day be 25% less than the out-of-doors doseom I n the ease of 8 truly emergency aftuation where potantid. hasa.rda may exist either from the fallout QP f ~ o mm ass evacuation of large populations, it would seem pmper &at due eonafderation be given to t h e biological repair process that takes place with radiatfon doses distributed. * This co ncq t was suggested after cmsLhy%ing data f m both the Nevada Test Site and the hiwetok Proving Ground and was intended t o give generalized estimates t o cover a wide variety of situations, with the smaller fallout patterns aromd the Nevada Tea% Site and with the sandy soils, the affective decay eonstants m y be greater than these, However, rather than attempt farther estimates for NTS a t this time, these values wjuB be used until the results of the expanded radiological monitoring program f o r Operation PLUIBBOB can be mdymd0 It is recognized that SHI. This is b a e d on an sve~age12 hours per day stay in P frame house having an attenuation factor of two. will be in bufldings having higher attenuation factors and f o r longer p e r may live an appreefable m o u n t of %%meout of doors and where windows and doors are left open, so the %a%fout matmfsl may enter buildings. Again revision of' this estimte w i l l await the results of the expanded radiological program of Operation PLUMBROB, It is recognized that some individuals 0x1 the other hmd, &hi$ is generally an area where people

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in time (recognizing t h a t such effects from radiation as genetic changes and life shortening may not be time The estimates for biological repair for m a n are q d t a uncertain 80 st canservrtive value is used here of a half-time of repair of about four ueeka, Graph I incorporates the above factors of weatherfng, shielding, and biological repair into a single emeo This graph may be linearly cuctrapolatsd t o other dose rate readings, For example, if fallout occur8 three hours after datonation and the dose rate is 10 P per hour, then a b u t 67 r (effective bfological dose) my be acermmulated, %BeoD Effective Biological Doses may be cde dated according t o Table I may be used in evaluating the fe asl bil it y of evacuating rslatively large populatiom , RADIOLOGICAL CRITzERIb FOR EVALUATING FEASIBILITY OF EVACUATION Effective Biological. Dose Minimum Effective Biological Dose That Must B e Saved By Act of Evacuation (Otherwise Evacuation Will Not Be 50 roentgens and higher (EPraeuatfon indicated without regard t o quantity of dose that might be aavad, providing adequate shelters are not a.vailablle and the estimated hazards eonzomitant with the evacuation are

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material has rdned in direct cola%actwith the skin,) greatly reduce this latter effect, it is highly desirable t o make decisions Wore or very ahorkly after the Start of %he fallout, shielding a t these early times will be of optimum benefit due tothe relatively high gamma dose rates. To prsvent or Likewise, part id Thus, the decisions must be based on predicted fallout fn an area, o r on dose-rate readings from field monitors' These predictions a r e of toupee subject t o varying degrees of Mcertainty 80 t h a t personnu1 may be asked to remain indoors unnecessarilyo On the other hand decisions and actdon must be taken solatively quickly if optimum benefits are %o be derived and remaining indoors until the radiological infomatian is more olccwatdy evaluated probably represents one of the e a s i e s t and effective ways of meeting an emergency situation, Due t o unceptain$fas i n QUI- howledge, and recognizing the usual unequal distribution of fdssa$, 2% haa no$ been possible t o establfah precisely the amount of %Uau,t 5n an area that could prodwe beta burns, The Marahallese urperfsnee showed rruclh effects for those people exposed t o 175 r and 69 P whole body gamma radiation, but none f o r those individuals on the Island of Utir%k (370 mXlee from ground Zero) receiving 14 roentgens.

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ioe o $ different particle size distribution, different type skin, etc, A t one location, Riverside Sabins, Nevada, about 1s people Were in an area rewith no known cases of beta b m a , although 2% is not known if anyone was out-of-doors during the I the of fallout, phenomenon, it would appear adasable lxl remab out of the dfr t ct fallout when the amount would be such as t o produce about IO roentgens gsmma infin it y dose as measured a t three %.et above the groundo personnel are out-of-doors d w b g Phe % h a of this mount of fallout, the possibflfty of beta burns could be greatly reduced by the simple expedient of changing clothing and of" bathingo Un%iL more is learned of this If people were n o t asked t o remain indoors during the period of highest doae rates i n an area whem the f nf in it y dose was 10 roentgens of wholeThfs would not necessarily bo hazardous but would exceed t h e When t h e gamma dose rate rea- as measured by a survey meter held =threefee%above the ground reaches the values given in Graph I1 at tho times fndlcahed, it is roeomended that personnel be requested tQ remdn indoors d%hwindows and doors closedo Relerse from this restrictive action should be made on the basis of further evaluation of the radiologfcs%conditions, I n the event that them be convincing avldance that the radiation levels given i n the graph w%ll be reachedg it is recommended that personnol Al

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radiation lt vols equal those in Graph 11, tivo octfon should be made on the basis of fmthor evaluation of tho Release from this rostricI t f a recommended that people who had been out of doors during fallout of t h o above magnitude or greater be advised to churgo clothing and to baths, The clothing may be cleaned by normal means. While bathlng, apocfd attentfon should be paid to the hair and my exposed parts of the bodyo In the event that the monitoring takes place AFTEZ tho fallout ha8 occurred, and extrapolation of the dose rate readings equals or exceeds thoso in Graph I1 a t the oathated time of fallout, thon it i s roeommonded that the samo addco bo givon as in the preceding

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"he principal pq o a csa for dax mtdna%b gpcpssomel areto reduce the potential beta doses t o the s k b , and to o 2,tssor degree reduce the external of measuring the gamma rad h tio as (ad;S,hm eatrapolatfng t o the accompanying have been denloped f o r direct beta measurement, but there remains considerably more work necessary B;a calibrate them in tams of beta dose rates t o The followfng eri%er%a were ?~~vfOU8lydeveloped on the basia Recently new field instruments Until this f a aeeompPishcd, the past criteria may be used,, Where it, is not possible ta monitor p ~ s ~ n n d .outside of a general radiation f%dd 9it i a recommended that an estimate be made of the degree of persomd~cont;uninat.ionby determining the there is un cert ah ty as t o $he vdfdi.t-y of such an esCfnate, the assump$ion w i l l be mad6 that the individual was out-of-doors during the time of fallout, equals OF exceeds 3bQ ;k.sontgs%aa,2% is recornended that t h e hdividual be advised t o bathe amd t o change clothing,

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field where perssmtEcontanlnstAan exists over relatively large areas of the EXPOSED body tome-half square foo$ or more): When the reading ofa survey in st merit hold with the center 0% the probe OF center of the ionization chamber equals OF exeaeds t h e values given in Graph I11 it ia recornmendod that personnel be advised %o bathe and t o change For personnel being monitored outside the general radia%ion field whore personnel ean$amhatio:! axiats over relatively a mall The recommended rnaxhm values ire one-half those gfvon fn Graph 111, Monitoring ~f .Wo head, arms, handa, lower legs, and feet w ll b be considered as eomfng undor this categoryo Mashing may be 1Mhd only tothe contunfnatod parbs, and d r o a ehonge of elo%hfngmay not be indicated, unless tho radiation P w u B s excaod thoee stated below coneamfng monitoring ui' e,aetepls.r surfaces of clothing, For pereomel being mon$%oredoutside the general radiation The reeomended maximum vahes are cae-f%fth ~ 0 8 0given In Graph 111, Waahfng may be limited only t o the eonCamhated p&s, and a l s o a change sf clothing may not be indicated d s r e the radiation Iepvgl~exceed those statod For personnel. being waomf$ored outside the general radiation fiold

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When the general esn~xmi.na..$fone€ a com w ty is of the degree to produce m estimated nna.sdmm $beam$ica% infinity gamma doae of 20 roentgens OF greater, perasmel who have been out-of-door8 a% any time during the f3r& two days and generally moving around i n the area (as apposed ts such building and a vehicle) ahofld be advised t o brush off the footwear after tRe final return fndosrs each day, In addition personnel ac% as walldng only between I after 8uch a fallout rhould be oM scd to wash their hands at least afhr the final se+um fndoara each day, and mare frequently, if

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herent in persollgel mod%arbg are applicable here plus additional ones, such as estimates of M e probabflftg of contac% and .elha amount of transfer of radioactive material from the vebicPe t o the skfia, !he following veloped, and until the new beta measuring instruments (see Sectfon 111) One method of avoiding 02- signi%fe%x4tJ~reducing vehicle contamination is t o prevent their being in an area during the time of actual fallout. It f a poas%ble that fd out across a Mghway may be higher than

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that trpffic be temporarily hd%ed m$%Bt h e fdSiout has essentially I t is recommended that when the predicted fallout across a main highway be equivalent to IO roentgens OF greater infinity gamma dose, vehicles be held unta the fdPoupI has essen tif iy Graph I V may be used in determining the advisability of decontaminating motor vehicles, be held with the center of the probe or center of the ionization chamber four inches from any readily accessible surfacee The survey instrument should

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In any area. wne~ar ashe thcosabncd g m u f&nni%y dose exceeds 10 roentgenso adequate sampl%ngsf the water, air, and foodst.mffs should be made to as cert ah the conda$fons of possible eontamination, if for no othor reasens than as prscautianarg m d documentary mea.cswos. past data, hewever, it f a not qac:$ac? %ha$ under those condtiana of fdl eu t where tihe radiation levels are beBm those stipulated for poasible ovacuatfm, t h a t the degree of con$aminatim would be a health hazardo Ner i a it hp l fed hera that my $eve8 abme %fa does ecpnstftuts a roriour contamination ad" …