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Letter from Acting General Manager Hollingsworth, Atomic Energy Commission, to Gerald Johnson, 27 November 1962, enclosing "The Biological and Environmental Consequences of Nuclear Attacks Using Clean Weapons," Secret, excised copy

L--------- ' _ _ JPY __ '__ _ _ _ _ _ _ ''' SECRET JPY N _ _ _ _ __ - _ _ _ _ - UNITED STATES ATOMIC ENERGY COMMISSION p ASHONGTON to DC Honorable Gerald W Johnson Assistant to the Secretary of Defense Atomic Energy The Pentagon Washington 25 D C Dear Dr Johnson In reply to your letter of August 15 1962 to Chairman Seaborg I am enclosing aco y of a dra ft report entitled liThe Biological and Environmental Consequences of Nuclear Attacks Using tClean' Weapons 1f This report was prepared by the Technical Analysis Branch Division of Biology and Medicine As noted in your letter to Dr Seaborg the report follows work done cooperatively between the Technical Analysis Branch and the Department of Defense Damage Assessment Center DASA lasting over the SUIll fler We would like to have your comments on the draft report A final report will be issued after we hear from you The DODDAC report as received in the Technical Analysis Branch on November 13 1962 Much of the information in it'had been received by mid-September inforn lly but most of the ps and some key graphs were not seen previously We are nO T reviewing the DODDAC report and may make some changes in our own report as a result Preliminary results of the DODDAC work 'I-1ere also sent to Chairman Seaborg under your transmittal letter of October 12 1962 We vlOuld also like to have your general comment as to the scope emphasis and degree of detail appropriate for studies such as this report represents so that we can plan more effectively for future work The Technical Analysis Branch is Just over half a year old and is still developing staffing and budgeting requirements Working relationships between AEC and DOD on this general subject are yet to be developed beyond the exploratory point for this first study and we would appreciate any cOllunent you might now have on the general approach suggested by Deputy Secretary of Defense Gilpatric in his letter of 1-1arch6 1962 to Chairw n Seaborg The Tec1mical Analysj s Branch expects to rely heavily on resources primarily within the purview of the Department of Defense and -- When separated firr ft1 r r rndle this document as ______________ -' __ _-' __ ______________ _ __'2 L i l1S0rt proper c ilsslfic tiofi NW# 44472 Docld 32586105 2 v JPY p DECLASSiFIED i Authority y tf 72- 1 ___ __________________ - - 2 as an example -- has already made arrangements for work to be carried out at the U S Naval Radiological Defense Laboratory and at the RAND Corporation Sincerely yours Acting I 6ffir Enclosure Report cy 1A I' j I I 1 I I 1 I II' I I 'I II I I I I I I I - 4' Docld 32586105 3 DECLASSIFIED -- Authority ' Y Lf Lj 72 This dooument consists ot _ pages o ' '0 SECRET J No o A _ of - _- 2 ___ Copies Series f L DRAFT THE BIOLOGICAL AND ENVIRONMENTAL CONSEQUENCES OF NUCLEAR A'l'l'ACKS USING lICLEAN fI WEAPONS November 14 1962 U S ATOMIC ENERGY COMMISSION Division of Biology and Medicine Technical Analysis Branch oa a Th S ' 't m l CjitD i1 1-' f j l d in th A 0 - t r ' htl C l' Of the n - SECRET NW# 44472 DocId 32586105 l J LtStJi'c uniiutnorizi cl d c j 1 r Hs a r 1 j i t a s 3j I aWl n hlnej tv p H1 Fi ' i J J I 4 DECLASSIFtilmE D ---- ------------ 4 Authority -Y --LLf--l'1L--7L-2 k - -_ I----- ---------- SECRET ' TABLE OF CONTENTS Page 1 In'traduction ' o o o o o o o o o ' 2 Scope of this Report ' 10 3 4 5 6 o ooooo o ' o Prompt Damage Assessment Input Information and- Methods for Estimation oo oooooooo ooooo o o o o Exposure Dose from Internal Emitters ooooooooooo ooooo ' ' o o o o o The Effects of Ionizing Radiation on Terrestrial Ecosystems o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o Conclusions oo oooooo o oo oo o o o o o 3 5 6 22 33 14-1 List of Tables and Flgures Table I - Special Attack Study Problem Table II Table III Ca ses Selected 8 - Summary of Prompt Effects for the 2L Nuclear Attack Situations o o oo o o o o o o 11 - Summary of Land Contamination Estimates for Two Agricultural Situations Surface Burst Cases Only oo oooo oooo ooo o o o o Table IIIB Table IV Figure 1 15 - Summary of Land Contamination Estimates for 1'1 10 Agricultural Situations Surface B-urst Only ' 16 - Relationship Between Fission Products and Other Radionuclides as Contributors to the H 1 Dose Rate Over Agricultural Land o o rr - H -l Dose Rate from All RadionucUdes at 10% Contour Figure 2 110 18 - H l Dose Rate from All Radionuclides at the 25% Contour 19 Table V - Livestock Sur vi val 20 Table VI - Fractional Uptake 26 - Estimate of Upper Limit of Radiation Exposure from Internal Emitters o 31 - Prediction of the Sensitivity of Plants to Chronic Gamma Irradiation 39 y 11 iii ' Crops Per Year from Soil ' Table VII Table VIn Table IX - Chronic and Acute Dosages of Co-60 Gamma Radiation at which Various Responses Occur in Two Pines P Strobus and P Rigida o oooo Docld 32586105 5 DECLASSIFIED Y 4'172 DRAF'I' TAB DBM I ffi det 10 8 62 It v lassified Title Reference The Biological and Environmental Consequences of Nuclear Attacks Using Clean Weapons Letter from Gerald W Johnson Assistant to the Secretary of Defense Atomic Energy to Chairman Seaborg August 15 1962 Introduction The Department of Defense by the letter referenced above confirmed its previously informal request to the Atomic Energy Commission that i t undertake a special nuclear attack study The problem as to make an assessment of the immediate and the longer term post-attack biological and ecological effects of a nuclear attack comparing different targeting weights of attack and degrees of i capon cleanliness expressed as the percentage of total bomb energy yield comir from fission For this problem the general target was to be U o S S R The weapons studied would thus be U S designs The problem was first presented to the Technical Analysis Branch Division of Biology and Medicine by Dr Johnson at a meeting in his office At the same time arrangements ere made whereby the Department of Defense Damage Assessment Center DODDAC part of DASA would carry out a preliminary analysis including the following steps 1 Postulate attack patterns including choice of targets and numbers and sizes of weapons 2 Provide other mostly technical input information concerning the country to be attacked such as population dist conditions type of agriculture maps etc This dClr tm lt c r t 1 s res ri li d data as defined GBP 1 1 ' ' 1 of ES1 I s tl r r aj d r r tt f tS G Hlents in any mltt disr to an 1If1 tilllJri' clJ p IS ln is iltcl'lib J In til' ot Ute A om iL -_ - _ I INW# 44472 Docld 32586105 6 o DllE C L A S SI F IE D -------- Authority y t f Lf 72 -- SECREl - 2 - 3 Employ exJsting calculation methods where available to estimate selected prompt effects such as blast casualties and fatalities 4 Develop new calculation methods where needed to cover gaps which appeared too important to neglect The main example of this was the cooperative effort with Dr Carl Miller tiA4uiJ k'D tv P d nL f ' OCD to develop a method for taking into account in predicting fallout such factors as a Fractionation of fission products b Particle size and solubility of fallout particles as they relate to potential availability for incorporation of the associated radionuc des into the biosphere and potentially into and anin ls persons I 5 Carry out by digital computer the actual calculations of selected prompt effects and related information upon which the AEC's assessment of biological and ecological effects would be based 6 Present the results of this work in suitable report form including tables graphs and maps Input information on weapon design characteristics was supplied by Los Alamos to AEC to DODDAC Informa tion from Li verlllore 4 s-tIftcl erstood-t'o-have furnished to DODDAC through Dr Johnson's office Input information on the physical and chemical characteristics of U S S R soils I aS provided by the World Soil Map Group U 8 D A and the Military Geology Branch Dr Carl Miller of OC -ae-a n indb id lorked ' I'i th DODDAC on calculat ion methods as noted above i I w# 44472 ---j Docld 32586105 7 DECLASSIFIED - Authority - - o o Y Lf Lf 72 SEGRET '----- ------ - 3 cope Of' r 'h Report Work done by DASA-DODDAC is bel ng reported in detail by themselves Y This report will include an appropriate discussion of the input information and teclmical assistance provided by others The AEC report - this report - will therefore consider the DODDAC 'report as suitable for direct citation and reference Its material rill not be duplicated here except as an essential part of a developing argument or conclusion Scope of the Special Attack Study Problem Cases Selected A stud y of the biological and ecological effects of attacks using clean weapons almost demands an approach that is at least in part comparative with similar attacks using standard thermonuclear weapons Direct fatalities for example are easily and effectively' studied by this approach Other hD' Hdh' effects such as from contamination of the ground would seen1 to need some 1 degree of absolute evaluation as well so as to give a feelj ng for relative impor cv G jor difficulty in comparative studies hm rever is that the comparisons may be rnade under such limited circumstances as to limit in turn the value of the comparisons because they can't be generalized For this study time limits were severe and therefore a miniInal number of cases each case being a defined attack situation were chosen These were based on the following Type of target 1 2 1 1 Military targets only U S S R Military targets as above and industrial targets combined Ti tIe of DODDAC report REPORT 1t throughout referenced simply as DODDAC -------------------- SEOtlEr Docld 32586105 8 DECLASSIFIED Authority y 4 tt 72 - 1 - Attack i reights to a1 yield 586 MT on mili ta '7'J targets J or 971 MT on combined targets 1869 MT on military targets or 3014 MT on com'bined 6037 MT on mil tary target s or 10 000 MT on combined 1 2 3 FOIA b 3 - 42 usc 2162 a - RD DOE E013526 6 2 a Type of burst 1 2 All air burst All surfage burst All of the cases chosen were pure cases i e no mixtures of weapon designs nor of surface and air l ursts Weapons were used in 1 5 and 20 MT sizes but of course the spectrum is not identical for the various cases The air burst attacks were considered to lead to no radiation effect The number of these cases 6 is therefore independent of 'deapon design For the one standard and tiVO clean designs used for surface burst attacks 18 add tional cases resul't A total of 24 cases thus forms the structure for this stUdY These cases are tabulated in Table I Prompt Daw age Assessment Input Information and Methods for Estimation All of this is covered in the DODDAC REPORT as to approach and results Some comment on the methods and results are interspersed in later sections ------- DECLASSIFIED Authority y i f 't 72 SECRET - 5 The Prompt Effects of the 21 Attack 8i tuations Here we consider the DODDAC esti w ates of the following effects 1 ntunbers of surviving people 2 nlJ mbers of persons defined as IIwell11 3 numbers of persons defined as l1well but who also received 300 r or more of external g8JlUllB radiation from local fallout 4 the average cmnulative external gamma dose to the surviving persons from local fallout 5- the-a V-e r'-a ge-e l a EUR-R' 'Fe-s i Q aJ -4969 to@ tlite-su r v i v i j lg ' f EURlrsOJ H from 16lQo l J a llout 6 numbers of surviving livestock 7 levels of land contamination from local fallout 1 NW#- 44472 Docld 32586105 10 DECLASSIFIED Authority _y 'f Lf 72 SECRET - 6 - TABLE I Special Attack study Problem Cases Selected AIR BURST Military targets 5 FOIA b 3 - 42 usc 2162 a 6037 MT - RD DOE E013526 6 2 a Milita ry ta rgets as above combined ' 'li th industrial targets 971 Ml' 3014 MI' 10 J 000 MT 'f Total Note b each attack weight was programmed 1'01' a spectrum of weapon sizes selected from three 1 MT 5 MIT and 20 total yield per weapon DocId 32586105 11 DECLASSIFIED Authority _ y '1 't 72 SEGREr - 7 - FOIA b 3 - 42 All but the last of these are summarized together in Table II usc 2162 a - RD DOE E013526 6 2 a I ------------------ This is to be expected ---------------------- From Table II one can o ra - the following observations 1 The number of animals surviving stays in rough proportion to the number of persons surviving This is not surprising in view of the fact that the attack patterns even for military attacks tend to coincide--in a country as large as the U S S R -with the places where people live and i here agriculture is carried on This is not to say however J that the surviving animals and people are necessarily located suffiCiently close to each other to permit an easy resumption of the aniwal industries post-attack 2 When clean weapons are used for surface bursts only in the largest attack sizes does the number of survivors people and livestock tend to drop 'dell beloi those for air bursts 3 The average cumUlative external gamma dose to the survivors for the clean leapon attacks is about 1 3 in each case that for the standard weapon attacks for surface bursts The worst case for clean weapons 196 r for 10 000 MT corribined targets is not nearly as bad as three of the six standard weapon cases 391 r 410 r 622 r for 3014 MT combined 6037 military and 10 000 MT combined respectively 4 The columns giving the percentage of w'ell people receiving over 300 r cumulative external gamma dose must be interpreted carefully 17 NW# 44472 DODDAC REPORT pageJ241 Docld 32586105 12 DECLASSIFIED Authority y L f't 72 sECREI - 8 These percentages are of pre-attack populations as noted in the table Thus if survival itself is low obviously that portion rho are trwell and highly exposed will also tend to be low SEORET INW# 44472 DocId 32586105 if 13 DECLASSIFIED Authority Y Lf't 72 I-- ---_ _---J - 9 o l-' ogzO 0 l 0 0' ' s 1- f-' cT III c r III Ii 1-'0 l O 00 '- I-' I-' 0' - o ' ' o 0 0 1 '1 0' 5' 1 Po 't III f-' 'q 'q I I cT c 00 01 LEGEND o' l-' l-' 1-'- --- Surviving persons fraction t - of pre-a tta ck population 1I s cq 'g Oti Well persons fraction of pre attack population V Ul 0 0 0 1-'' -0 --J-40 00 0 0 0 0 -4 --J 0 0 l f'- 1-4 f-' H o oCT l o 't ro w H I-d Well persons as above J rho also received 300 r or more lifetime dose 5 Average lifetime dose to survivors Surviving cattle fft tiQ70I Of pre attack population Sf 1 - 2 000 000 I I I 0- 11 W 0 '- 000 1 I t Sci f-' 0 e c tJ j H I 1 't CI OW' - '-' 000 H - C o - ' As above 1 0 CoWVl 1 o I 0 I 0 I-' f'- 0 0 O W cT P' 1 I - I-' W Vl WV1 v g H H I-' I 0 l p- II 1-' 0 0 0 0 0 - rs r-' '--' o 000 1 0 0 c ct PJ Q J I-' W Vl I O W I I 0 I I I-' p- Ul 1- 't - 1 11 wO CP '-' 0 0 0 25 g vi 't 0 s 00 It II 0 0 ' -00 FOIA b 3 - 42 USC 2162 a - - 0 0 W OI-' RD DOE E013526 6 2 a 0 O 1 1 f I-' 00 --J 0 l 0 f J1 0 00 o I II If NW# 44472 DocId 32586105 14 DECLASSIFIED Authority YLJ Lf 72 SECRET - 10 Footnotes for Table II preceding page 1 From DODDAC REPORT which gives bacY round for development of these numbers usc FOIA b 3 - 42 2162 a - RD DOE E013526 6_2 a -------------------------------- I Pre-attack population 210 million persons 1 41 See DODDAC REPORT for interpretation of well 2 External gall'lll'k'1 dose from local fallout clUllulated j Pre-attack population 71 mHlion cattle see DODDAC REPORT for sheep and pigs 11 NW# 44472 The DODDAC damage assessment system does not estimate cattle fatalities from air bursts For most of the surface burst cases percentage-wise the cattle do slightly better than the people and this 'tlould not be unreasonable to assume for the air burst Cases too Therefore use the percentages in column 1 as a rough guide If anything the percentage survival of cattle would be even higher approaching lOO survival the survival of the rural human population for the air burst attacks is estimated at 10 DODDAC REPORT p 14 Docld 32586105 15 DECLASSIFIED Authority _ y 4't 72 - 11 - Estimates of levels of land contamination are presented in the DODDAC EPORT 1 for all the surface burst cases for two situations Atoms per square foot deposited on cultivated land cropland in the U S S R for mixed fission products for 6 selected fission product radionuclides biologically available for 2 selected soil-induced radionuclides and for resid ual weapon material radionuclides 2 Atoms per square foot retained on the foliage of all U S S R agricultural land cropland plus grazing land as above This tnformntion is presented graphically in the DODDAC REPORT as a series of cumulative distributions showing fractions of land area not contaminated al ovc a specified number of atoms per square foot Not all of the different types of contamination as listed above are actually shown on the graphs because of the crowding that would be caused but multipliers are given by which any curve not shovm can be readily derived Information taken from the DODDAC REPORT is sununarized in Tables III and IV The plan of preseDtation has been to take a look at the levels of contamination corresponding to the contours containing the most contaminated lOi - and the most contaminated 25% - of the U S S R land area Such contours are of course fictitious in the sense that the actual areas of highest land contamination are spotted about over the U S S R The DODDAC REPORT maps suggest the actual geographical distribution The n l dose rate from all radioactive atoms - at the 10% and 2510 contours taken from Table III and columns 5A and 6A Table IV are plotted for the different attacks in Figures 1 and 2 These plots show that the H l dose rates are lower by about a factor of 10 for the clean weapons 13 NW# 44472 Oocld 32586105 16 DECLASSIFIED Authority y t f Lf 72 SEGREl - 12 - The result can be viewed in another way when combined lith the livestock SUTvival information Table V 8hO' O 5 the 8urvi val of livestock only cattle are shown but - as the DODDAC REPORT graphs show the result is little different for pigs or sheep goats outside Le on land contaminated less the l - and the 25% - contours for standard and clean attacks For the andJ clean attacks some cattle survive inside the 25% contour except for the t fO largest attacks even the 10% contour For the standard-weapon attacks only the smallest attack gives any appreciable survival of cattle inside the 25% contoUT and in no case is there any survival inside the l contour This result is to be expected from Figures 1 and 2 It might be asked why the lCP o and 25% contamination contours tere chosen and why not the 5 or even the contaminated land 75% contours i e why not look at less The reason is apparent from inspection of the DODDAC REPORT land conte mination graphs giving cumulative distributions of land contamination atoms sq ft These might be regarded as the result of sUJmning up areas inside the actualH 1 fallout contours as estimated for the U S S R land area The horizontal axis of the graphs ranges from roughly 1016 atoms per square foot of mixed fission products down to 1012 or so before going off scale The lower value represents an H 1 dose' rate of about 1 r rrt visuallzes that l011er contours will not include much more land area One But not' all 01' the total U S S R land area is accounted for much of it is uncontaminated from local fallout as predicted by the DODDAC model Therefore the lOi of the U S S R agricultural land area most contaminated is really a higher NW# 44472 Docld 32586105 17 f' TABLE III of - - Summary Combined targets co - - 1l 2 0xlO1 5 6 5xlO15 2 2x1016 971 ill 3014 MT 10 000 Mr 7 3xlO14 2 7xlO15 1 2xlOI6 1000 3250 11100 8 0xlO13 2 6xlol4 8 8xlO14 370 1350 6000 3 cr l013 1 08xlO14 4 8xlO14 40 130 440 1 3xlO1 5 4 3Xlol 1 5xlOl o -P -P ro s H l tlD ro -g c 0 'g -j t5sj ffi tlD sj -1 0 -1 Utll'lj @ 0 fj o d c l oP u u cd l sj o O -1 o 'tr- s o 3u a' l-P 01 o l --- g0JPYl j o -1 '0 ' rz lj lj Q S 1 From DODDAC REPORT u Q Q 0 H U till lj d 4' -j rO V til l J 0 m '1j o u H l'1j P l l ' 'r 0 -j fl -P ' Ul 1 -rlO S J'L t u u 2 650 2150 7500 0 N 16 54 240 0 1 lxlol3 5 2xlO1 3 2 3XI014 26 r l 6 85 t 5 26 300 Cl 115 -P -P ro l 0 - -1 5 2xl013 1 7xlO14 6 jxlol 4 140 650 2900 1j l 0 1l - 'r I01 ti ' -1 N 0 --- 'g --- g N U u 0 D t rl 0 00 'H 2 '1j 'H 2 '1j S 0 H -P ro l tr- 8 0 S '0 J 0 l o p H 3 p S 0 t ' cd l fl roP ' H 0 u u -j H H 0 Ul N oq -P-P01 m l-P H 0 U u S 'lj l w't RO om$- p OJ p ' U N C ' 0 0 Q s H H ' 0 t 1 2 3 Ix 4 U 0 0 hich gives background for development of these numbers except as noted below Calculated from 1012 fissions sq ft - 1 r hr at R I CZl CZl 1 ' l 'r 01 ro 2 8xlO14 1 3xlO15 5 8xlO15 -P -P'H'H ro 0 o a' 01 o m'--- 'r C J 01 -P S 1j -P 0 sjUl-P - s m m tlD -P -1 lj d Y 0 I ' -j Military targets 586 MT 1869 MT 6037 MT N N r- 0 GBP s # - Z 11 - 3 TABLE III-B Summary of Land Contamination Estimates for Two Agricultural Situations L j i Surface BlITst Cases Only -- III N Combined targets D 1 3xl014 7 8x1014 2 2xl01 5 971 MI' 3011 10 000 lvTI 2 1xl014 9 8xl014 5 0xl012 3 1xl01 3 8 8 xl01 3 8 4xl012 4 0xl013 0 N I f M H 0 M 1ilitary targets M 2 Oxl013 3 5xl014 1 Ox101 5 586 Mr 1869 MT 6037 MI' 'ri ' j t5 '1 H o o ro h s Ul -00 -1-- ' o ul til H H ' P p lOO O ' ' ' ro O 'H -rlOO ' Ul t d ro Q 'rl 'O H Ii cJ rl d Q 1 8xl012 1 6xl01 3 III H N Ul D ro ' rl r-l c o I -I ro 0 0 ' t Ul ' lOr-l -o -l l Ooo'H H Q'rl P bbd P 1-1 m Ul O l l ' 0 gJ3'g CiS b1J N D orl J ' H CiS ' CiS ro cd ' ' 0 0 r4 l o OorlO ' oroorl'H a H ' r J b1J o o I cd 0' l 1 4xl013 4 0xl013 8 Ol 1 a'l -I ' ill cd c -1 p ' 4 5xl013 4 Oxlol 4 o -0 l 1 -I 8 Ox1011 -- 'f N 0 ' I' CO 'I' M QJ JCl o g -riOO ' ro ' o 'cd 0 LI' J -ri 0 rl Q Ul lj13 Wp O LI' H 0 r _ '0 H U 0 Ci C f o S 5 r rJ f o Q NOTE -EURo -5 l See preceding page for footnotes 6 5 6 N r-- q' oo r oo r # Z DECLASSIFIED Authority ---Y LJ Lf 72 SECRET - 16 TABLE IV Relationship betl een fission products and other radionuclides as contributors to the H 1 1 dose rate over ae ricultura1 land FOIA b 3 - 42 usc I I 2162 a I I - RD DOE E013526 6 2 a Combined targets 6b 971 MT 3014 MT 10 000 fLilitary 16 32 108 260 880 240 480 52 170 6 26 12 115 230 54 targets 26 85 300 586 MT 1869 MT 6037 MT 600 52 Table III column number 11 I iNW# 44472 Docld 32586105 20 Authority it 2L #33 E01 3 DECLASSIFIED Authority Ail-2L DECLASSIFIED _AUthority y 72 - 21 - LEGEND Fraction of pre-attack population surviving co W 0 0 co 0 o CD ' I 0Q V1 Fraction of survivors 0 surviving outside 10rf0 contour J Fraction of Burvi vors b surviving outside 25% 0 CD '-'00 '8 g contour 3 J -CD O - 'E I --J Fraction of pre-attack population surviving outside 10% contour g r- Fraction of pre-attack co population surviving outside 25% contour J V1 j '-J As above 0 1 0 0 0 0 co - l I ' co CD 0 0 00 II l-' o FOIA b 3 - 42 usc 2162 a - RD DOE E013526 6 2 a J NW# 44472 Docld 32586105 23 DECLASSIFIED Authority y 4 Lf 72 - 22 - percentage of that agricultural land area having any contamination at all There is little point in estiw ating contamination levels lm rer than that shmm in the DODDAC REPORT Appendix F of the DODDAC REPORT gives inforrr J'1tion on the decay rate of mixed fission products soil-induced radionuclides and weapon material residual induced radionucUdes Figure F-17ff p 68f f' gives the time integrals of the dose rate curves for two assumptions about fallout arrival time one hour and five hours This information is developed for a single Heapon and does not take into account the effect of overlapping fallout patterns from multi-weapon attacks The information is a fairly good indicator however of the origin of the external gamma dose over various periods of time FOIA b 3 - 42 usc 2162 a - RD DOE E013526 6 2 a i f - This paragraph added at the last minute after DODDAC REPORT was received it will probably l e slightly revised and relocated in the final report -I NW# 44472 Docld 32586105 24 - DECLASSIFIED J -- -- -Uth- -Ority_ _y_L f_ _72--- J __ SECRET - 22a - Exposure Dose from Internal Emitters DODDAC made no estimates of the exposure dose to persons or animals or plants from i nternal emitters This 9ub joo't is very OOR lifiJ1ex requir treatment for each chemical element - in some cases more than one nuclide or at least groups of elements It is common practice however to eliminate many of the fission product and neutron-produced radionuclides from consideration by qualitative arguments 1 These may be surrunarized as follows The half-life is extremely short making it fairly clear that little or none of the radionuclide would reach the bioshpere 2 The half-life is extremely long leading to the argument that the radionuclide is essentially stable or in any event there is time later to lido somethinglT about it This argument o Ould have to be used carefully with sayan alpha-emitting bone-seeker 3 The element to which the radionuclide bdbngs is known to be transferred into the biosphere - or at least into the parts of the biosphere where it could be incorporated into man - very poorly That is it is noli taken up by plants or by animals or if ingested by man even is NW# 44472 Docld 32586105 25 J ----- -------------------------DECLASSIFIED Authority 'f 72 SECRET - 23 readily' eliminated from the bod 4 The radionuclide in question has a sister whose probable dose contribution is so much larger as to make consideration of both an unnecessary burden hen time is limited Needless to say no special revie r of internal emitter toxicology and supporting information relating to transfer through the biosphere has been ' made for this report Both DODDAC and we have made arbitrary choices of which radionuclides to even attempt to make a quantitative estimate of dose for It is clear however that the validity of this approach for the purposes of this report should be assessed keeping the following factors in mind 1 16% and 82% of the U S S R population are estimated dead from the smallest and the largest standard-vreapon attacks respectively 4% and 57% are dead from the corresponding clean-weapon attacl s I 2 attacks received an estimated lifetlme external gamma dose I of 130 rand 620 r respectively I I 1 'rhe survivors of the srnallest and largest standard-'I eapon From the clean attacks ltO rand 200 r respectively 3 Some internal emitters notably 1-131 are by present methods estimated to produce rad doses to the thyroid ranging in the thousands and hundreds of thousands if no countermeasures y rhatever are taken This is true for both standard-weapon and clean- veapon attacks but the fission product doses in this report would be estimated to be for the clean attacks 4% of the estimated doses for the standard-weapon attacks however estimated ECrrff INWi 44472 Docld 32586105 26 DECLASSIFIED Authority y l f't 72 ---------- J EGRET - 24 - 4 Even in the absence of countermeasures obvious factors such as the lack of live milk COV S to transfer I -131 to milk in the heavily devastated regions ought to be taken into account In short it appears possible that omitting certain radionuclides from quantitative consideration is not introducing errors appreciably larger but perhaps much smaller than those errors already included in the overall assessment of these nuclear attacks _ --_ _ _o - - NW# 44472 o _ J Docld 32586105 27 DECLASSIFIED Authority _ y L f't 72 - 24a - The following radionuclides are given some specific attention in this report these are picked out from those i-lhose amounts are estimated in the FOIA b 3 - 42 usc I 2162 a - RD DOE E013526 6 2 a 1'-----_ _ _ _ ---- ------1 There are two general path ays for these radionuclides to reach the diet l ptake by plants follm ring deposition on soil with a possible following step of uptake 'by animals grazing the plants -v- l 2 Retention by the surfaces of plant foliase with a possible folloving step of uptake by animals grazing the plants -cV -'-- J -'rJ Table VI has been worked out from a brief review of the literatureYon plant uptake from soil Some rac1ionuclides listed are eliminated for further consideration because of half-life Others are eliminated because of low uptake by plants Of the radionuclides listed in Table VI only Sr-89 and Sr-90 ofOuld be at all likely to constitute an 6e e Hiiefifil exposure hazard worth considering in addition to the external gamma radiation dose insofar as uptake from soil is concerned For these radionuclides the maximum exposure dose to persons from clean-weapon atts cks would be estimated as about standard-weapon attacks uJ a Iv ' N to foliar contaminatlonJ 1 The 4% of that for the corresponding DODDAC REPORT says that foliar retention of radionuclides is estimated as a function of fallout particle size according to the follmling scbeme I See ackno o ledgments NW# 44472 Docld 32586105 28 DECLASSIFIED Authority y t f't 72 SECRET - T --------------- j- - 24b - TABLE VI Fractiona l Uptake by Crops Per Year from Soil Sr-89 0 01 Sr-90 0 01 Cs-137 0 001 ' -140 0 001 1-131 0 01 Pu-239 Ru-106 0 001 - 'U-237 FOIA b 3 - 42 USC 2162 a - RD DOE E013526 6 2 a Short life precludes uptake bazard - Possible upta ke ha zard for onl l on year INW # 4 4 4 7 2 Docld 32586105 29 DECLASSIFIED _AUthority y 72 SEGRET - 24c Atoms ft 2 foliar retention Atoms ft 2 total Particle size f 0 ' 0 L 5 1 50 l Foliar deposition is furthermore unlikely to be of muchJPY-mportance beyond the first growing season after the heavy fallout This is based on the assumption that the great bulk of the ' orld-wide fallout would occur within one year following the attack and the local fallout much sooner Of the six fission products certainly sr -89 could contribute a bone dose of the same order of rragnitude as that from Sr-90 The Sr-89 dose w Quld mostly come from the foliar depo'sition whereas the 81'-90 dose comes not only from foliar deposition but from soil uptake 1-131 furthermore can produce doses in the thousands of rads or more to the human thyroid principally from foliar deposition But again maximum doses from clean-weapon attacks would be estmated to be about jc of the maximum doses from standard-weapon attacks Both Sr-89 and 1-131 have ha lf-lives in the 5 to 50 day range ivhich tends to maximize the foliar deposition route of entry Longer half-lives permit uptake over longer periods than one grmving season shorter half-lives scarcely permit any uptake at all ________________________________________________________ IFOliar deposition is probably the route of entry if any because uptake from soil 'l'able VI is low Plutonium is not metabolised by animals to an appreciable extent Intake from eating vegetables with surface contamination is PosSible FOIA b 3 NW# 44472 - 42 usc 2162 a - lID DOE E013526 6 2 a Docld 32586105 30 DECLASSIFIED Authority _ y L f't 72 StGREr - 24d - FOIA b 3 - 42 usc 2162 a - RD DOE E013526 6 2 a MPCso1ub1e 1 MPCinso1ub1eY Sr-90 10-6 llX10- 4 Sr-89 10-4 3x10- 4 relates to critical organ dose relates to gut dose Docld 32586105 31 I DECLASSIFIED Authority _ y '1 't 72 SECRET - 24e - FOIA b 3 -G-c J - 42 ll 'Appena'1 X A vIe usc 2162 a - RD DOE E013526 6 2 a give an estimate of the maximum do Jes from 4 internal emitter fission products to be expected from the various attacks on the assumption of no countermeasures is valid For I-131 we do not believe this assurrrption These estimates take into account both foliar and soil uptake as appropriate but are nevertheless only rough estimates Carbon-14 is usually treated separately its mode of entry to man being virtually unique because of the role of carbon chemistry in organic matter The production of C- L14- is estimated by DODDAC to be approximately 50% higher for the clean weapon attacks than for the standard weapon attacks be true for air burst attacks as 'well as surface burst attacks This will The air burst attacks are estimated to produce twice as much C-llt as the surface burst attacks ' because of the difference in geometry in surface burst attacks 50% of the escaping neutrons are assumed to be absorbed in soil The genetically effective dose from this source for the levels of attack of this report is in the range of from a fraction of a rem to 2 or 3 rem r 7 Computed for a fast equilibration time of 27 years and a slow one of 200 years These doses are not the BOOO-year infinity doses Docld 32586105 32 DECLASSIFIED Authority _ j YLf Lf 72 _ _---1 t- - SEORET - 24r - 1m estim ate of the size of the internal emitter dose has been made using as a basis for estimation the contamination levels of all agricultural land cultivated plus grazing at the 10% and 250j0 contours as'previously defined Devastation including the death of milk cows would be expected to reduce the contribution to dose from the more heavily contaminated areas '1'his effect has not been allowed for The estimate is summarized in Table VII Clearly the important contributor is 1-131 although some of the others contribute sizable doses in relation to the prompt external gamma dose It should 'be carefully noted that the internal emitter rad doses in Table VII are not average values for the survivors but are upper limits of what might be expected from food-chain Uptake' at the contours representing the most highly contaminated land in the U S S R tqtal agricultural land 10% and 250j0 contours as noted above Even for Table VII some of the levels are so levI as not to Shovl on the DODDAC REPORT graphs smal attackS 2510 contour The doses in Tablc VII assume no countermeasures and are total lifetime doses For 1-131 and Sr-89 dosc delivery is in reek and months I FOIA b 3 NW# 44472 - 42 usc 2162 a Docld 32586105 - RD DOE E013526 6 2 a 33 UJi LLASSIFIED '_Authority - 24g - LEGEND Maximum dose to thyroid - expected fro I -131 at 10% contouyg total -- agricultural land rad Ow 1-' V1 0 0 V1 11 00'-000 0 0 o0 0 ' 8 00 0000 0 0 0 - As above ' 25% contour I-' f rad I- xi III Pj-J III c S Sr-89 Range of dose expected from intern emitters lCP o contourl 0 5 Sr-90 1 3 to 130 rads usc 2 0 CS -137 - 42 j-J to 50 rads '- FOIA b 3 0 III 0 3 to 30 rads 1 2162 a - RD DOE E013526 6 2 a H I- Ii H I-' As ---I-' I-' above O '-# '- -l I-' O l t '- II ' ow -oow 000000 000000 8-CD 11 g I-' tzj 13 c - --J I-' -CDW 1 1 1-' I-' 0 0 0 I As above r-- oo oo ' 00---00 - Sr-89 0 02 i til It to 2 rads - t As abovell Sr-90 0 05 to 5 rads '-- Cs-137 0 01 to 1 rad al NW# 44472 Docld 32586105 34 i DECLASSIFIED Authority '-i t 72 - 2hh - Footnotes for Table VII preceding page Not shmm on Table Pu-239 - not higher than Sr-90 standard or clean weapon attacks c-lIi - 2-3 rem maximwn Au burst attacks tWJ ce as high as sU1 'face burst clean weapon attacks l ti mes as high as standard weapon attacks i e 1I 10% ' See Table FOIA b 3 NW# 44472 most highly contaminated - 42 usc 2162 a Docld 32586105 - RD DOE E013526 6 2 a 35 -- ---------- DECLASSIFIED Authority _ ' y t f't 72 SEGRll - 25 - The Effects of Ionizing Radiation on Terrestrial EcosystemsY Research ort environmental biology pertaining to the effects of ionizing radiation tends to fall into two categories 1 Studies of' the transport and distribution of radionuclides in plants and animals and chains of them especially the food chain leading to man 2 Studies of the effects of ionizing radiation on ecological systems themselves Relatively much emphasis has been put on the former especially for a few radionuclides such as Sr-90 but relatively little on the latter It is only recently discovered that certain plants are damaged by total radiation exposures in the same range as those Jhich cause damage in mammals Certain plants are especially sensitive to damage from ionizing radiation The gymnosperms include some of the most radiosensitive of plants the algae and bacteria some of the most resistant the order of several thousand fold The range of sensitivity is of For example chronic exposure of pitch pine Pinus rigida Mill trees to average levels of less than 5 r day for several years has killed more than 90i of these trees while exposures in the range of 1-3 r day inhibit diameter and needle growth Near the other extreme of sensitivity among the higher plants Arabidopsis survives chronic exposures of several thousand r day instances still more resistant Bacteria algae and fungi are in many In general the trend of research on both somatic and genetic effects on higher plants is toward recognition of effects at lower and lower exposures 1 7 This part draws heavily ''i'ith much direct citation on the following reference Woodwell G M The Effects of Ionizing Radiation on Terrestrial Ecosystems report BNL 6408 NW# 44472 Docld 32586105 36 DECLASSIFIED Authority _ y L f't 72 -SE8REl ' - 26 Differences in sensitivity to damage are not restricted to differences beb een species but also occur at various times during the life cycle of an organism Reproductive stages in plants are apparently generally more sensitive than vegetative stages lethal effects occurring during flo tering and seed set at approximately 1 4 the exposure rate necessary to cause 100% morteli ty among mature plailts radiosensitivity Tables VIII and IX illustrate this differentiaL In animals variations in sensitivity among different stages especially in insects have been recognized for many years The implication is clearly that time-of-year for an attack will have a bearing on ecological response The effects of exposure of plants range from death through varying degrees of growth inhibition to effects on reproductive capacity o It is important to recognize that in general the research thich has described these effects in plants and which has yielded estimates of sensitivities has been done on small populations under cultivated conditions in greenhouses or gamma radiation fields conditions specifically designed to reduce variability attributable to environ mental stress The introduction of the various forms of environmental stress characteristic of natural ecological systems can be expected to intensify the damage from exposure to ionizing radiation and to produce' effects measurable at lowf r exposure levels possibly to produce additional effects not recognized previo usly For simplicity we have divided possible effects on ecosystems into shortterm and long-term assuming short-term to mean less than 2 years In most terrestrial ecosystems the short-term effects will be' dominated by the consequences of differential sensititivitks long-term effects by these plus effects on reproductive capacity ind genetic effects -- _ _ NW# 44472 Docld 32586105 37 DECLASSIFIED 'Authority y t f Lj 72 - 27 Two types of short-term effects would be expected from high level chronic irradiation of an ecosystem first selective mortality of sensitive species due to direct and immediate effects of exposure second shifts in the relative importance of' species populations' through alteration of the biological interactions which normally contribute to a stable pattern of ecosystem behavior These interactions include not only the many vaguely defined inter-plant relationships commonly hunped as Hcompetition II but also parasite-host and predator-prey relationships There are nu 'llcrous models suggesting potential consequences of such shifts in biological interactions Some of these have been summarized in the literature Research on the effects of ionizing radiation on organisms living in natural arrays is complicated by the variability of these arrays and the necessity for recognition of slight effe'cts caused by the low-levels at' exposure present In addition effects of exposure are usually confounded with location making clear separation of radiation effects from other environmental influences difficult The lowest chronic levels of ionizing radiation at hieh non-genetic effects approximately 2 r day on higher plants have been observed is Although it is probable that effects on pine stem diameter and needle growth could be observed at lower levels perrmps 1 2 the exposure rate-used for the above estimates a large factor exists between 'general background radiation levels and the lowest level necessary to cause a measurable effect in a sensitive plant There is now therefore little reason to believe that effects can be seen in natural ecosystems except in those exposed to local fallout from experimental bomb bursts and in such ecosystems as that adjacent to the Lockheed reactor in Georgia To produce such effects even in ecosystems containing pines which are among the most sensitive plants known BEDREr J NW# 44472 DocId 32586105 38 DECLASSIFIED r_Authority Y'1 Lj 72 S ORH - 28 chronic exposures in the range of 1-5 r day would be necessary while to produce parallel effects in 01'11 6 minimum exposures of 10 r day would be required Much higher levels ' ould be necessary tol- kill these plants wi thin a short period and to cause presently recognizable morphological effects in other more resistant species Data have been developed indicating that 1J' l environmental stress increases damage in plants caused by any level of exposure to ionizing radiation o A suggestion has been made of one mechanism explaining this effect In any case the possibility seems to exist that exposure to ionizing radiation reduces tolerance to environmental stress and that ionizing radiation rill prove limiting to survival or to normal development of plants at lower levels in irradiated ecosystems than under cultivated conditions We WOUld therefore expect to find non-genetic effects in the most sensitive plant s in natural arrays at long-term exposure rates of the order of 1 r day Longer term effects of chronic exposures on organisms living in natural arrays are dependent to a higher degree on the nature of the contamination and on an additional set of biological factors Such long-term effects are necessarily the result of exposure from both internal and external emitters and it is clear that to predict effects of exposure for any type or intensity of contamination the mineral cycles and periods of residence of isotopes in various organisms must be known Progress is being made in defining these cycles and their biological implications I ess progress has been made in defining the biological considerations which are important in determining potential long-term effects considerations seem to be three These First ionizing radiation is generally r--' -- NW# 44472 Docld 32586105 JJ I 39 I _ DECLASSIFIE Authority Y t f Lf 72 SEORET - 29 deleteri'ous to living systems and exposure can be expe'Cted to reduce physiological tolerances to environmental stress Although notable exceptions to this generality exist especially as a result of clever genetic manipulations by man evidence from animals and an increasing body of evidence from plants indicates strong interactions between stress and radiation exposure suggested that relative dam ge sensitiv ty It is among species to this type of radiation probably parallels radiosensitivity shown by morphological characteristics The extent to which this is true remains to be seen Second variation in sensitivity to damage during the life cycle of an organism may be extreme making the population as a whole much more sensitive than the mature stages of single organisms In general reproductive processes are most sensitive to damage vegetative or mature stages least sensitive On the other hand there is no threshold exposure for production of mutations Third selective removal or differential inhibition of species will alter biological interactions potentially upsetting the usual abundance and ecosystem stability pa terns of species This type of distUrbance can have three forms alteration of interspecific interactions among plants shifts in the host-parasite balance and shifts in predator-prey relationships There are abundant models for these types of distur bances ranging from the removal of chestnut from the extensive oak-chestnut forests of astern North America by the fungus Endothia p'arasi tica to nmnerous animal populations stl ldies All of these changes produce potential instabilities in ecosystems ranging from the initiation of a new successional sequence only slightly different from the old to violent oscillations in population density which can result in extinction or in population explosions The research needed to elaborate these large and complex problems is NW# 44472 Docld 3258610S 40 DECLASSIFIED Authority - I 4 't 72 - 30 - itself large and complex involving the delimitation of model systems and the analyses of these systems from numerous standpoints Perhaps'the most successiDLecological study of this type is the series of studies of the sprucebudworm in Eastern Canada carried out over more than two decades and involving many scientists Although ionizing radiation presents a different set of problems from those posed by the budworm the Cruladian work emphasizes the need for long-term integrated approaches to such large scale and fundamental biological problems A second type of example has been provided by chance at Rongelap Atoll and on neighboring atolls in the Pacific and at the White Oak Lake Bed at Oak Ridge Similar examples must nmr exist in the Russian Arctic Use of these examples' as they are available in conjunction with experiments involving mineral cycling and the effects of internal emitters not only on organisms but on populations and ecological systems as well will provide at least some understandin g of That is happening to the environment 1'-NW # 4 4 4 72 Docld 32586105 41 r DECLASSIFIED YLf 't 72 Authority ' SEGRET 1 --3-3 - TABLEVJI Prediction of the Sensitivity of P nts to 'Chronic Gamma IrradiatlonliPercentage of the daily dose causing 100 per cent mortality LD100 reQuired to produce various responses in plants chrbn cally exposed to Co-60 gamma radiation Response normal appearance growth reduction failure to set seed 5 Jljo grovlth reduction pollen sterility lO Jljo floral inhibition or abortion growth inhibition severe lCJ% LD50 LDIOO Daily dose 1GBP of LDJ QQ 11% 26 31 31j ' 41 4 t 58 75 100 II I I 1 A H Sparro and G M Woo d le 11 Radiation Botany 'X 2 1962 9-26 I I wlt 44472 Docld 32586105 _----42 TABLE cL Chronic and Acute Dosages of Co-60 Gamma Radiation at Which Various Responses Occur in Two Pines P Strobus and P Rigida1l Responses Normal appearance loi growth reduction F ailure to set seed Pollen sterility 100% 5CJC o growth reduction Growth inhibition seyere Letr al P Strobus 15 month exposure total dose z r r day 2 5 3-4 n40 1370-1825 P Regida 9 year exposure total dose z r r day 1 5 2 5 5 10 20 2280 4560 9120 3-5 5-7 12 3290 4250 10 600 6350-10 600 10 600-14 850 25 500 Strobus brief ga rn 113 dose l r P 40 60 160 275 600 L o r-1 0 co L N Y ' 0 H U o a Q rz -l -l e Q N l '- 0 1 0 9 l -cr 7 t' t' t' # s z DECLASSIFIED Authority y '1 't 72 I EORE - 33 Conclusions 1 Clean weapons obviously provide a method for lowering the exposure dose to persons animals and plants 2 The amount of lowering is not that predicted by merely comparing fission yields The dose contributed by radionuclides produced within and outside the weapon becomes proportionately more important for IIclean H as opposed to standard weapons 3 A dose comparison on a per-weapon basis is not meaningful because an allovrance needs to be made for the spreading out of the radioactive debris follo -ling the burst and for overlapping patterns of fallout The mere fact that the spectrum of radionuclides changes from clean to standard weapons ensures that these enyironmental factors -Till affect comparative doses 4 The six attack cases using all air bursts are not particularly relevant to a comparison of clean and standard weapons for the method of damage estimation omits any contribution from the radioactive debris These cases do present nevertheless a benchmark against which the possible advantages of clean weapons can perhaps better be evaluated The air burst cases give a sort of limiting picture of minimal casUalties and fatalities and - by assumption - exposure levels zero FOIA b 3 - 42 usc 2162 a - RD DOE E013526 6 2 a 6 Clean weapons lead to reduced fatalities and casualties for surface btlXsts especiall l in the larger attacks iNW# 44472 Docld 32586105 The same is true for livestock 44 DECLASSIFIED r Authority -If - i 4 'f 72 SEOREl t - 34 fatalities Interestingly the livestock-to-person ratio runs about constant This is not too surprising from the methods of approach used in this study Very roughly the people and the agriculture and the military targets of the U S S R and of course the industrial targets are in the same parts of the country considering the vast relatively unused land area 7 The survivors of the clean-weapon attacks very clearly survive with a 10i-ler lifetime gamma exposure dose - a factor relevant to the subsequent I state of their health 8 Clean weapons expose the plant life to lower doses How important this is depends on the application For example crop damage may be lessened from the clean attacks but en the other hand mere people survive whO' will demand feed 9 We have leeked fer e ch attack situation surface burst at the fictitious contours defining the most highl contaminated lCfJ o of the U S S R agricultural cropland and the 2510 centour Thus 'He are talking about 1 10 and l l j of the cropland not of the total U S S R land area which ensures that we do not devote too much attention to very small but highly contaminated areaS The maps DODDAC REPORT p 261ff show qualitatively that if criteria of acceptable or unacceptable hazard are applied to these two fictitious contours with judgment we are not likely to come to wrong conclusions about the consequences of the attack cases studied FOIA b 3 - 42 usc 2162 a - RD DOE E013526 6 2 a I J Docld 32586105 45 I DECLASSIFIED r Authority YLf 't 72 SEORET - 35 - 11 The biologically significant internal emitters from fission arc of course reduced in quantity by the ratio of fission yields in the clean attacks compared with the standard-weapon attacks Neutron-induced activity in soil is about comparable FOIA b 3 12 - 42 usc 2162 a - RD DOE E013526 6 2 a According to present methods of estimation rad doses to the thyroid from the ingestion of I-131 can run from thousands to hundreds of thousands of rads But these methods ignore the possibility of even elementary counter- measures The higher end of the rad dose range numerically estimated is unlikely to occur because survival of the milk cows is unlikely I' I For this i study it has not been possible to correct the 1-131 dose estimate for this factor because it is not clear what the livestock survival is in any specific region where the contamination level is high in relation to survival elsewhere 13 If the population had better shelter than that assumed in the DODDAC REPORT it is possible that the internal emitter dose would become relativ ly much more important compared to the external ganuna dose If one wished to I but such a goal is not necessarily meaningful if the population is not well sheltered From the pdnt of view of occupancy of the U 8 S R by U 8 troops i c NW# 44472 'ftllil Docld 32586105 I I reduce the internal emitter dose the advantage of clean weapons is obvious 111- o tI I 46 r I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - DECLASSIFIED Authority y t f 't 72 ' --- --- - J SECREl - 36 - I i 1 1 using their o m food supplies t TO characteristics of' clean eapons stand out ' iI I a The external ga na dose is less for a given attack by about a factor of 5 to 10 b n This dose is delivered relatively faster so that if troops do not occupy the U S S R land area until about 100 to 500 hours post-attack the dose left to be delivered is very small DODDAC REPORT p 69 c Shelter occupancy times - to keep the accumulated dose belO a preselected value - would be shorter for the clean weapons 15 A short statement about the ' lOrld-wide fallout will be inserted 16 Insofar as i external ga dose effects on plants and U levels of internal emitters are concerned it is difficult to believe that either factor will be limiting to agriculture in an absolute sense Either the situation 'ill be so bad that other factors such as availability of equipment or of farmers viII be limiting or else some sort of counterme sures will begin to be worth considering This remark does not of' course mean to cover such possibilities as real ecological devastation from the combined effects of fire radiation and selective biological depletion and enrichment of species I II But as discussed in this report these questions are far beyond I our present understanding SESREl _ oo __ _----------------- Docld 32586105 j 47                     National Security Archive    Suite 701  Gelman Library  The George Washington University    2130 H Street  NW  Washington  D C  20037    Phone  202 994‐7000  Fax  202 994‐7005  nsarchiv@gwu edu