Nuke weapon effects

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NUCLEAR WEAPONS
EFFECTS

PREPARED FOR
EMERGENCY MEASURES ORGANIZATION
PRIVY COUNCIL OFFICE, OTTAWA
By
DR, EE. MASSET
DEFENCE RESEARCH BOARD te aA Mes
NUCLEAR WEAPONS EFFECTS

PRODUCED FOX

EMERGENCY MEASURES ORGANIZATION

ey

DR. E.E. MASSEY

DEFENCE RESEARCH 80430
NUCLEAR FEAPONS EFFECTS
IRTRODUCTION

‘Aconsiderableneed as existed for un cubertetive publtcetioe on austoce
respons effects fot could be toad and aderstoad by eom-tnckaleal ometgency

seus ail clit defence planning officials, Existing pablcaiocn in thls Meld
tay Lave bien ton vagus 0 120 complicated forthe avemge reader.

‘Tha mnunl waa prepared hy (he Defence Resestch Foard atthe rqaast
of the Emergoocy Neamuse Organization toll hin med. Uille [Je not Iotended
‘hat ths manual ba a aubatitate for auch ublicatione ae the "Etfents of Nucleer
ospoar” which 1s published by the U.S. Asoo Enozey Comission fr Mighly
qualled technical redera, it Sx hoped that i will provide seficeat uptodate
‘and scewate infomation for those engaged in emergency plenning,

Peivy Coaacit Office [ENO

arch, 153,
WUCLEAR WEAPONS EFFECTS
Table of Contents

Tnodsstion

AW BUR esses
Ground Shoe =.

Bypleolone dn Wate.
“Theamal Renton.

Radiation Effects.
Tastes

‘Tele — Reletive dagtees of afects for valous burst sonditons «+...

‘Toble — Peok ovorpressutes ness ground s0foce <=. ..-.- 1210

‘Tehle IH — Haxlmm dyranle pressiwes sees .

Table WW = Moxtnum mind speed ss osesescase sees see teteeeieeeiee

"Table ¥ Times of arive of peek oveqtessutes ...p-cs- set eget ecotsee :

able V1 — Oaration of positive phase, .
‘Toute VOL — Vevea wat welded uremmensee cieeecenteensen
‘Yoble VII — Reltions betwasn peak ovarprecoeres and straccural alla...
‘Teble IX — Maximum renges fom ground zero for etucrral denape trom ale bret «
‘Table ¥ ~ Crater dimensions foe surface bart lt dey soll eee sess
‘Table x — amoge criteria for nogartely deep madorgound stacewes «oes aene nee
‘Table XL — atinated overpeasures for dltect blast caeualtler a
‘Table MMI — Veloce, wesese sed dencitles of lraawate.
Table XIV. — Probailies of giees fapmeats penateting abdominal cavity,
‘Toble XV — Woapes effects for ait bursts with manlalzod ranges a
‘Teble X01 = Theva effects oss s eee
Talsle VME — Ignition onotgy for various mateiala ++
“Tale XVIII — Frequancy of exterior Lauon pots ia a ity on

‘Table SIX — Ranges thom gen ceo fr vais file ralllln Juve fn si bal
‘Table HX ~ Heighta of brat above wich nelighve easly Callout is produced .....,
‘Table X37 — Radlatlon Protection (otOI9. ses ssessasscsconseecesececteeeci eewees
‘Table X21 Doce rate eduction Foctog mfoted to dooe rao ot 1 T hrs.
‘Table ll — Lifetite dogs factors related 10194 14068 0 ss esese ree vens
“able XXIV — Half ive of sone redllantopes,
‘Table XV — Dots fer high yleld wespooe spose eceecsesene

‘Table XXV1— ave heights producad by auclese wenpont at specitied tances from
safes 2200
NUCLEAR FEAPONS EFFECTS
Dr, EE, Maaoer
DEFENCE EESEARCH BOARD

(The dete contained hari are ton tally fom “The Efacta of Nuclea: Weapons”,
Washingt, 1962 Balter)

1. Nasloat ealosions range i1 energy seleoae (or Myitld"”) from a few toot, dhovgh Kilotons CL
‘iteten “1,000 tans) to any megstoue (1 megaton 1,000,000 tone) equivalent of THT. One kitton ts
sutltsaly defined es being easel {>
19% calories
hich senate
Ga 10" args
ka oe fo foe
15 4 104k
1B 10 bas,
soergy of 350 tons emi, and cones Ste the Deion of
18 10" octet
ot about Zowneex of U ae Pa.

1 To thoer sho have not sean cae of thear explosions, Agus aad units mesa very lite. The
Nepisakl bout was ied at 20 kilolonn lew auch energy Is 20 kilotons? Perbops oe of the mare meanlng-
Tall statomonss 1s to sey thet fis amount of exrtey suitskly applied could raise a ship the size of the
(Queen Wary oo ight of seventy miles, A 20 Rt bomb releases ‘on tines as much enwcey 2 the explotloa
of the tmunddion ship Woot Tilane, which vs carging 2008 toae af THT, and whlch al: but destroved
ntifas in 997.

‘3 Ertesdlag ths asalogy, ane wezsten ould be mareseated by the eralorion of = fine of such
shin ten to ster an estendiog for tmanty alles. Even bo, th 18 small conpered alth ta energy eeleagad
fn name ratoral phannnana Khas henn calctlcted tha thin i ccffniant apagy to kaep « Mica a
taslenns for about teenly aaconte, The Operation Tey (eat of Rovenivar 1052 Liked 1/90 cuble niles of
sural sand — the Kenkataa (East Fniles) voleane, le 18AS, iad 1% eahie milan, Much Lagér dutatiten of
‘moti have haan cjctad in soa teas wall knot volomnie eaptlons.

“41 must he understood that Were are alvaya wncerainien in may geanitatien ante given fot
apeclilc weagocs effects. Fltaly, thete are Inherent dificalties in naling exact mesuronarte beceuse,
ven in teats, all conditions connot he contain. ‘Than, tuo espns of fhe mame Sield nay bave diferent
eltets, bacause of dilereaces In daeigs. Vacetalties are iatedaced by the condtians of biel height,
fpeued ype, tensia, wenlies, ond by the extne of the atic, an well at by the chesactotctice of he
farget complex Kind and consi of buildings, dstefbution of peceli Heace, only very appresimete data
should be used in plonning. WIth thle Hnltetion, it te poceible, Lnoniag whet ane alge noepon ill d
Cesinate the effect of x difarant alae weapon. This process ix called “ecaling'

Ts convenient to coasider Weepons effects under four headings

‘Blset

‘Then Raetlon

Anitial Nucloor Resition
Residual Nvclee: Relation

6 These wilt be ciscossed in tum. Theit rlstice effectiveness for vatlous types af burst in indi-
‘ted in Toble Lf the Append.

‘i Blast
7. The high temperature of the Bzabll ofthe explosion heats the adjaces: ex eo such a degice thet
its te of expansion poducns shock wave which trvels in all dlvctona fom the pont of burt.
‘a, Tee damage reouting fiom the aly blant of the ahock wave may be bright about ia te mays.
Fist Ghee inthe sudien iasvenga Ia presaure whee the blest wave orives, Ths qsoaa0re riser almost
ue called the “peck overpressore” and thea gradually Glls off, che time teen for

ure to eetun Lo stooepheric being longer a greater distmnces fram the seplosion, and for latest
yield explosions
5 The pene overpeetsure inthe blast wave before it atikes anything 18 desesibed as the “Incident
peak overoensire”. then it ests a awrface reflection occurs, and the pressure, cow called the “flected
‘overressnre is incseosed ae icioated ia Table VIL This occurs wh each seflerton,

10.Aa the blast aren angilis 2 stortue, pepssure Gtlereoces act Ypih it arch oF dafoam le
‘Tais is called the “dfrenton effect” ox “ditimetion lauding” and the dagree of danage depends eu Se

magne ofthe caak overposaure (See Appcedix, Tabiee Il, VD,

‘1. Sacoaly, Innedlaely following ta shock ft of th blast wave thers Jo « ang wind (Appee=

fix, Table 1V) which lous aa long at tar prenante fa above atmospheres This 3

1s dyeamic pressace (Table

‘9e of the imporast Ziflereycea belwoun lage ascten: Bass and shales hgh eaglesive blast

fo the aplication of

ID for ag lng ae the wind blows, The long dutation (Vatle VO of es wisd ix

hs affet

on siretures i calle the “érag” ffect Mhehor tne dffexction or dag efcx dominates in causing donage
fs partleulor steacaure depends om the ae sad shape of tae stvctore and whether fis anchored down,
Aaylhing which Is sot anchored down, or which as rlaLively alender strctural wenbecs, wll respond
‘redomineatly to drag, eich trgots are poles, towers, tons bridges, ales fimne buildings wlth fongible
alls, wekicles and people. Horses, ax well as tote mative sinceres, wespond ssialy to the action

alice,
Th The folloning stems how the dletence te ponluct a particular eect seaiee with the yleld of ie
respon.

if Deg of ‘Reage of effects or slauural™

[svete Damage weapons of

_ tke DM Bue
Wood tame Moderne (eid 3500 0 35,0007 Toa
overs eming cred, smile) ailes) (4 afesy

out ally domnged, H
{nesor perttoas
‘town do
oiserey Moderate (walle 2500 t 25,000 4 50,0008
wall-beering beats cached, ale) Galles) 10 mites)
Des, apatt= smcedor partitions
ment hones bodty ercked or
we blown devo)

2. Muticcrey Severe fame 600 2900 f
steal fame istic, te 4g ife) ites) ites)
ofthe Bldgs clpeat collepoe
wlth Ligat
cuala walla

4. vetictos (Need mor peice 10 18,000 ft 40,000 &

alley 2% miles) sites)
Blows donn 1300 6 21,000 304000 f.
om (tes) aitesd
Cunasveree
fevaicetton
of test)

* For ground mutt wenoda multiply thee 1
1 Naantere [acd 2 are difraction tye argee, wi

ate by

3,4 and Save doog type reste.

1B, The dideace at which « opeclfig peak overpressure le produced Tx proposal Wo the cube vost

‘of te weapon yield TUS is soma i the demuge distance foro “alfetion” target, Dag de

1 tenets

fut nly on the prewure but upon tho Jeogth of tise the pressure 13 applied, Tas duration alsa acalen
cording to m cubs root law ao toa for large yislds damage ditences are greuer then world be predicted
by sealing pressare clone ‘this Le selected in the demegr datancaa given,

ae
14, Ar Mes og sh, sot am boat dicot cause of cma, Slant cables salt
sndecly by cllpeag bull, gina tei or hy hy aopscamers Taide compares the expected
Hale! ef are epartes ts inter dang ort te svt lene

TE The putes fea of Rone debs haniter) ye ddd fice Tbe at

46: Be tla je te stance acct te pact wth» Ye ote to th 10
fon pur teond i elitly te pce © get ur f seus jue: hen 8 20 fe pet
tevin cove thle boy oar vd ste tow or cosa he prety foal ny see
‘Spy sit incesing velo At? wilco tom tn srt ne ong # 166k nan sina vlog
Fst ver 20 fc persed et ghee of 1 fot

12 'pma's cinednson of fe mochntins ty which cesice ete sean allows Gey even
ster sisal dog nay bo consi, tna conalee can ba set meet by hla cove

nn else gn, ing Ss ad gh wo

S08 tmnt Sly bate th eration wd the ato he le Ge sae sto at
thee day beeen a ignng Banh ead tandecogs Ye Sack wave els mec fer a,
Gin oped of sven eto thus Jose wafer mony eodlnos fo people Ante op aes te
Chasse a uel in th nea bameon the csp sed te slo te Lisa weve

Grovad Stock

18. A wespon borat asa the ground aurace will ruse some ground shock and prodace » crate
‘The groand shock may cause some Gamage to below gourd installations #g shown in Table XT. Crater
inensions for surface burst ate glven in Toble 3.

Explosions in eter

20, Butts in water will goneito «shock move Which wavela through Ge Wales, and is called a
‘oat shook", It ean cause damage to the hills of vessebs aid to dite culents. (yedallon water waves
te stented which troral ceaciderable distances and may ofuse dacage by floodiog, Heights of seven ate
‘itoatt to predict, They dopead, oot only onthe size ofthe wewpon Fut, in etion, othe depth af ater
sod the dopth of bees Maver ore smalls for ures im shrllowcr water, The depth of Dooding they crass
depends on the composition and vontuur of the bottom near the shove, nd the nayle of incidence of he
sprroacting wave, bot aader the furat cmiitions Gooding soph oon be tice the height of the eppreachieg
‘wore, Wore heights resuting (tom underwater nuclear bausts ate given in Table RXV.

Thermal Radlation

21, Stating st the momeet of the explosion, considorable heat 1€ given ff, This thems sedition
‘tavels with the sveed of lirkt: Indeed it fchaves easentially like Tight fm ll tegpects The Jongth of the
sflecilvethecnal alae increases with energy sled

For 1 Moten itis oughly 6.3 seconds,

10 wegatons it is roughly 30 ceeends,

2%, Becanse the thermal caditica ie 9 similar t Light in behawoor it con be stepped by any
fopagee material, Moreover, vaiatoas in snaspheris conditions ~ clots, haze, ng — mil modify the hast
radiation in exactly Be sine wey they modify suligh, Geeupe of thn it ix imparafble to prediet exectly
vwhat will happen tony partionar city attacket,

2), As night be expected, the larger tho wanzon the grestts the fhemal encesy emitted, and ot
Doin at any spaclfed distmce Em tke point of >uret the total quantity of heat delivered Le roughly propor,
Hionsl to the yield ol the weapon for the sane etnospherc candiints. Hance, if a 7 Moot delivers
alone persquare contineter2¢ 1 nile fom the point of bust, 2 100 kt bom would deliver 100 caloica rer
Savare continster atthe sane distance under tho sone canditinan. What happens te 9 eustave which roccbved
Yhemal radiation depends won hom much therealrasrlon It eceives end how Tae it receives fe

24, Tho un delivers woghly abme 2 calories per =qeete evatineter per mlacto to the earth ‘The
four colostes delivered ia ono minacex y he wun have v decidedly warm fecling, bit tt to all: Delivered
‘in 30 mecuads by @ 10 mt explosion 4 calories par eqiate contimeter oncees a itt degre bon, rad
‘ellvered in 0.3 seconds hy # Ke meglasin i enzone 4 ercond degree bee
25, Distoncee to which bume ca by axpacd from vasous yield weapons a given io Table XVI.
‘The beat of the mua setts fem fine, bat 1 calovieg por ewere centimeter fe 410 mt aaplonionigaites
Bredded novopapee, aed frm at it axploaion It will ignite dy rotted woot (Table XVI) The pole
Undies wr sterting Bec will be spporset from Table XVI. All ree stir ot small Gres, and, If un
hacked rithia a few master, many Sens ney mozge to prodace larger fims. Vf balding densities me
ficiently Nigh, lags Sree miy megs inte meas Brea of fix storm or cenlageation propardone, Wik
Jarge weapons, » ccostderable faction of a targa ores {2 pototilly note guleerable to Bre thn to eevione
loot daage (ase Table XV), and Bie possiilty of dealing with incipient fice ie very roel i theae

2, Coleen of rime for Uncset effects of very Inige meapons on gromd targets Sead ty aver
catinates of damage and ceeeuites, ecw be auger: mamiveion date availa ore eable only
ap to datencos as great so belf the viability (eee Table XXVb

127, itis ingouant to rember that Gh thermal tedltn ta topped by any opaque matelal, becouse
the seplication of this fact cam reduce tos and ptysical injuries voip meckedly. ‘ores sn Ioflmnaste
eter in Bullingitetors 23 06 prevented by thoding the windows with Vetetlan Mads ot siite-mesh,
‘even though tbe subsotueat blest blows ov. tie wiadotn. Many flres cas be peevented by somorlng fe
‘uumabte test tes back yerda ~ plain ordinary “goed housekeeping” in foot. The prevention axpect of
defence ognize tharmal affects canaot be emphasized tov sroagly.

2 Clothing atforés some protectin agalvat themal injury. At least two layesa of clothing oe
rats, Clothing should bs leone, the outer layer should preforebly te of light eolaur, snd lune retdaat
‘wentnent ie edvantageonss

Radiation Efacts
‘, The povtlenlor ind ofzadatlon which is of moat concen to energenry plannarcin gare raison.
‘This ie mach He very goveetul Nays. Ie tewvels in xtnigh Hines sith the anqod of Hight and will sadly
penetevte pager materiale.

1h, Won o nuclear devioe ix detcoated, comms radiatina te enltind, Tt 5 this whieh Le Largely
cesponsthle fr the INITIAL MUCLEAT RADIATION bazord If peocle sseive anongh gemma radiation, they
nay get sick or even die, bari ie imperact remember that this gemma volition doce NOT make saglhing
‘oF eaytody tadioactive, For @ Lat weapon the gauma doa at 1; mileo fram tha expleaio would Ye ler
saffcient to cause sciness in expoced people (Table TIX). Nh larger an Larger weapons The importance
of Intnl radiation becomes less ood Less ly compasinue with Ghe bet and themal aflec> (See Table
XY

41, Simuttanenualy sith the onzlon of the inital sndiaion = lenge momar of mdcactive eeweula
sare prodaced ty the Fsalon of atentun or platonhus. These compounds aim collectively called fasion
oducts. At the high tenpetetine of be Freel! iL van be ensued Ul ll nese ane yapoued on that 38
‘he eball conte many Cort not all) of there ebuloncen vontinee welnctivey to a fine duet, These dust
Paricleo aight be comparable in size to the Water devote iv tae cloud that txoven ftom the pout of =
felling kettle, ond, ful for uthor intervention, would fll tthe gvonnd Jae 98 Saat

32 W harper yucicles to which the Hine dust can acots becoae Inoaporeted Into the cloud, 6, or
feuumple, the ditt raised when she explosion cceurs near the gownd (Vable U0), tha, bacalae fhe larger
partes ‘ell wore rapily, “eeny folfout” may occas. This takes place within 24 hours. The ae of most
sericun becard after a giotad surface burst generally went from the falloat of vieibte peices, Their
sizes conge ftom that of ce sind in the move stent parts dat of mall marble, with tho biggest ones
feling noe ( ground toro,

The dint raleed by » grosad sarface burst may tring dows up to 5) to T0% of the tadioaceve
‘naterinl in the cloud, The remaining dsl may be brought doim ty rait, necks, xontho ct Years late
‘Gnost anyshove on the earih’s mulace, This is “delayed falloat™, ond Becanor of tha Changer it has
undergoe in the acsoline itis oot tre to say “bet goes up mast come dav”, Those eady eadinctive
fallout tends oa anything, that thing is sald ta be coataninated, It iz Important ta dimingglsh betesn
“oclug imediated” and “cing contaninated”. Survival opetstions are concord arly mith the early
fedlout, ond any furthe refereace ta thls manoal to “Erlfeat” Sill eed “eauy tallow
34, The gman radiadon sven off hr the radioactive GH has 4 range of several hendeed feet fa
it, Therefor, its notascessary te come nto dimetcontact with ibe ido be svbjectedto tbe entered Meson
fine its rediation. It bax been extimated Phat SO ofthe doar that @poveon would receiv, If be weve stende
Ing in» faltur aan, would come from more thna 50 feot away and 25% frtt alecces in exceos of P00 fot,

3S, Stopping gaome sedition fs not az simple ea stopping thee rad.tion More weave amounts
of nielfiog ax excennary, A town Leoqeently enevan\cred in discusting radiation abieiing ts “ball inchs
‘neos ayer. Thiv mesas the thicknass of metriel which mavess the intensity of redftion pag though
‘0 50% on, To hal! whickncos layers (whether i contactor wat) radoce Inlewly tos 2h = 4, layers
sedoce 10 GE,

36. The half valoe tayor of concrete far initial dation te abone 4 inchce, and for talation uf
‘Sizer energy to that frm fltout abowe 2 laches. ‘To be aitlely accanite the Well thickness lager apple
cooly to & nai rnfnton bene fom a point source, Hlth ceil acon the mejor problem he prteetion
fam the radistion of scattered dim over» vary extensive aefone (iy Grete, owe aypmyaive tw etre
abicldlng factors fin various stmetatea hea the sof and Uae suring ground see cootraiaatede A
umber of these Farts ae gives in Tebte

37s aulition to gras sediatiog, eutrons 279 ontted at the tine of explosion, and fasion products
cenit beta gaticles. Unfinsioard bomb ateral wll ene alpha pattcles, Noutone hevo e oomewhet dwrar
range than eorima radistlen, hat taen similor efecia ex people, and hare the powtr to make corte oul

(ces sadloacive, ‘Thus, nutrons contribute 4 ialal radiation, wo may comune to Femdaal rioting
ifthe fragt s8 tain neutron range ofthe bass.

438, The range of bela panicles 1s aaly few yun in alt, Thera, they contibate mainly to
residual activity. Thare 16 6 risk of buna If beta emitting matelale ae allowed tp mala In contact Mite
bedy tssee Alpha particles donot panetsts the shia m they constitu & hazard erly mies alpba suitors
ate taken into he body.

3, The orctcctive elething axed in survival operations i te prevent bath exiting dirt tom ccaing,
{oto contact wth tbe akin. Since thi clothing fo mado of clonely moven cloth 5 dose not protect again
mais inflation, Protective clothing 56 saply ererotla.headgeny glover aed foot eas

2. One promincht Tontue oftadioactivity, hich comes stent trom Hts reiy ectieity, te th 1
srdaally decays. Booty radiosetive aqbatmaes bao ste own ate of deoiy, which be invatable, end i
‘rtwrooed a the time sulted to love bat of tte actrltys Tels fe called the “hall We". Eaamples chowing
ow hat Ties vets widely fram one madloentopa te castor ere given ia Teble XXIV.

41. Flaston prodocts, boing a niztne of anny tadiotnatopen, hava a dafiite bof Hie. The be ite
Incrnases wih agh. The decoy fe wore complicaod ond can, ik tonereh be crpreased Ly ibe satonent
Toe x sevenfold inet is decreed tetfold. ‘Thin fw ainpitiae

shore T in Sntenslty2t tne aed
Wie snteaaity 1 hour after explasioe,
0 wpecitic valece, It mean, for exemple, thal the activity at» cesta place at
HiT near 19 100 meatgene por bour
then ot | Thoorsit willbe ID
thea tC 49heure Hndébe LH
Then at He Donecke twill Lt
then at B63 aomthe i ill eT “
‘Tis reletonahip 1a valid Wilkin 25% fr tines afer the explosion between 30 nlastes aa 200 days, jo
vided there Ia 40 chings inthe quantity of falloat ding the tine faterval wide considertiva, The ford
sanget be used while fallout Sp til dacending, ori o¥étl ply follnd [rm arta wt diferent Snes, or IE
much woathering as uccure. Fence, man actual sltuncon the decay tie mut be Venfled Wy meestemest
25 Gioqundly a3 pute.

"LH can be seen Ut the sdioactvity fale of dating {tp say Llfe compared 10 late, noe the
telative benefit of ouly a few houre prtection dying the ently Ife of the sion pradacrs. Foruaateiy,
sone of thls protestiog Is suionruic ~ euch decay occurs before lion aru, and the tcther dom ind,
he greatey the deley 1s efore Callout eine,

42, Poutng tie
“4 te fellows from the dacey eqeation that the dose rnceived by renautg indefioitey at a place
thors De intently le rat tie fll be Sh, Foe avanple, ithe aettlty at a place 3 homes afc the horet

1s rocetgeno gor hour, the done secelved bemoan} hours and balay would be

Sx dx 1B + 25 roantanne

45, To onder to determine the harend at any contaainatat place i will be apparent thet itis not
sufficient wy how the Goss cate only oa mat Enon too, the tlm since zero. This noptiex whether Hin
Sineetion of aymg wore ove 40, a of going ilo © contamlactod atea either 19 work orto oe, Te
Inatte this pint, take the eanaple given shove of w doze rae of IS sntgens par hour st 3 howe after
but Ti, at ether Hines of ceading, thie same dose rate mere obisined (at difesnt places, of craze the
Glowing lletive dones weutd be obtcined:

ar IS fhe at Lhe feline" done ia Be
AS s/he at hee ” 2 mt
As rhe ot 26 kom keer

“The diierce hese ix sather siting, though peshagy nol oa sealife oc the dose serulated Sa ony, the
ert Db hontes Ths works ot 2

Ts hs at be DW houedosein aT
15 be at 3 at nea sO
iSvheat bs ae
46, Dosage is accumulated a follows lon {1+ 1 hour oavard fia terms of Kfetine deve}
Pon H et telly Sbre Di of liletine dose
Hed tol +12 zo “
new a ae oe
eSdase tH + Gombe wee
Hs 6 mowthe t9Lifetion mse «4

Here egain the vale of protection during the early burs ta clearly damonstrered,
47, Protection ousinst the Zodition from early fallow: ca be sommed ap ander three headings
Distonet — The furtor avay the feliout dapost tno less is the exposure.
‘Shielding — The groster the anoent of mataival batroen oneset end the fallout che lanai the exposure,
‘Time ” ~ (a) Duration = The shorter tae exposure to ration che Less will be the raatian absorbed.
= (b) Delay — The Tongsr the delay tn exposing mesetf to fellouttedatios the Tess will be the
sadiation absetbed for equal utstlen expstur,

area 1985,