Effects of Nuclear Weapons - Princeton University

1 Effects of Nuclear WeaponsAlexander GlaserWWS556dPrinceton UniversityFebruary 12, 2007S. Glasstone and P. J. DolanThe Effects of Nuclear Weapons , Third Government Printing OfficeWashington, , 19771 Nuclear Weapon (1974, 1998): 1 + 5 Pakistan (1998): ca. 6 North Korea (2006): 123 Introduction / Overview4 Burst Types Air burst High-altitude burst (above 100,000 ft) Underwater burst Underground burst Surface burstIn the following: primary focus on (medium-altitude) air bursts(fireball above surface, weak coupling into ground)5 Effects of a Nuclear Explosion Thermal radiation (including light) blast (pressure shock wave) Nuclear radiation (prompt and delayed)(35%)(50%)(15%)Typical distribution of energy released6 Effects of a Nuclear ExplosionSequence of events, Part IFIREBALLfor 1 Mt explosion.

2 440 ft in one millisecond, 5,700 ft in 10 secondsafter one minute: cooled, no longer visible radiationFormation of the fireball triggers the destructive Effects of the Nuclear explosionstarts to form in less than a millionth of a second after explosionseveral tens of million of degrees: transformation of all matter into gas/plasmathermal radiation as x-rays, absorbed by the surrounding atmosphere7 Trinity TestFireballMach frontShock frontDirt cloudJuly 16, 19458 Effects of a Nuclear ExplosionSequence of events, Part IIFireball becomes doughnut-shaped, violent internal circulatory motionAir is entrained from the bottom mushroom cloud if dirt and debris sucked up from earth s surface(Source term for radioactive fallout)

3 RADIOACTIVE CLOUDD uring expansion of the fireball, vaporized matter condenses to a cloudcontaining solid particles of weapon debris9 Cutaway showing artist s conception of toroidal circulation within the radioactive cloudSource: Glasstone, Figure of a Nuclear ExplosionSequence of events, Part IIIAIR blast / SHOCK WAVEA fter 10 seconds of 1 Mt explosion:diameter of fireball: 5,700 ft, distance of shock front: 3 milesWave is reflected from surface, both waves merge to create Mach wave Pressure wave develops immediately after explosionand moves outward from the fireballDuration: about 10 seconds for 1 Mt explosion (99% of total thermal energy)THERMAL RADIATIONR eemitted radiation from the fireball (secondary thermal radiation)11 Heat and Shock Waves(Film footage: Federal Civil Defense Administration, ca.)

4 1955)12 Effects of a Nuclear ExplosionSequence of events, Part IVINITIAL (PROMPT/DIRECT) Nuclear RADIATIOND efined as radiation releases within the first minutemostly neutrons and gammas (directly from the explosion or from fission products)DELAYED Nuclear RADIATION / FALLOUTO rigin: material lifted into the fireball right after the explosionMixed with radioactive residues of weapon (activated debris, fission products, ..)Early and delayed fallout: Depending on height of burst, weather conditions, Blast14 Shock Wave and Winds VelocitiesPeak overpressureMax. wind velocity100 psi1400 mi/hr50 psi 900 mi/hr20 psi 500 mi/hr10 psi 300 mi/hrSource.

5 Glasstone, Figures and , Table Characteristics forSpecific Overpressures Light housing destroyed5 psi__ Brick housing/commercial buildings destroyed10 psi__ Reinforced concrete structures destroyed20 psi__Representative data, from Physical Vulnerability Handbook Nuclear weapon storage bunkers100-500 psi__ Command bunkers100-1000 psi__ Missile silos500-10000 psi__ Deep underground command facilities1000-10000 psi__ DamageOverpressure16 Percentages of Population KilledSource: NRDC, The Nuclear War Plan: A Time for Change, 2001 Original source: OTA, The Effects of Nuclear War, 1979(as a function of peak overpressure)98%17 Peak overpressures on the ground for a 1-kiloton burst (intermediate-pressure range)Source: Glasstone, Figure Y18 Analysis of Attackson Hiroshima and Nagasaki Calculated value of the Height of Burst (HOB) for 15 psi1640ft1900ftReal valueHeight of Burst at Hiroshima and Nagasaki chosen to maximize areaover which 15 psi or more occurs ( miles in diameter)( times more area destroyed compared to surface burst)h=3 Y h1h=3 15 670ft 1650fth=3 22 670ft 1880ftHiroshimaNagasaki1920 kt.

6 MiHeight of burst selected to maximize area over which 15 psi or more occurs2 Mt: mi200 kt: mi20 Impact of Fizzle-Yield Explosion3 kt2 ktSource: Ted Postol, MIT(Area of complete destruction)21 Thermal Radiation22 Thermal Fluence and its EffectsQ(cal/cm2) (kt)f R(miles)2 Glasstone, Equation partition f: about ; Transmittance to target on the ground: Figure Human skinSecond degree burns6 cal/cm2__ Human skinThird degree burns10 cal/cm2__ Fine or course grassIgnites8-9 cal/cm2__ Deciduous leaves6 cal/cm2__ Paper4-10 cal/cm2__ Cotton shirt (khaki colored)21 cal/cm2__ Type of materialEffectQ(min)Glasstone, Tables and FiresInitial fires (started by the thermal radiation) combine and form super fire Minimum thermal fluence required.

7 About 10 cal/cm2 High velocity winds directed towards center of fire, chimney effect Firestorm developed in Hiroshima about 20 minutes after explosionDeath caused by heat or suffocation24 Mass fire: mi200 kt: mi25 Nuclear Radiation26 Effects of Acute Whole BodyExposure to RadiationSource: United Nations Scientific Committee on the Effects of Atomic Radiation: Sources, Effects , and Risks of Ionizing Radiation. 1988 Report to the General Assembly, United Nations, New York, 1988. Annex G, Early Effects in man of high doses of radiation, in particular, Table 13. Similar information is listed in Glasstone, Table > 3 hrs1-2 hrMinutesLethality0-10%0-90%0-90%90-100% 100%Death occurs withinMonthsWeeksWeeks2 weeks1-48 hrsLeading systemBlood forming (bone marrow)IntestinalNervous1-2 Sv2-5 Sv5-10 Sv10-50 Sv> 50 Sv100 rad = 1 Gy27 Initial Radiation1000 rads for 20 kt explosionDiameter: 2 x 4100 ft (ca.)

8 Mi)(Dose absorbed in the first minute after explosion)28 FalloutEarly fallout fraction for surface burst: 40-70% within one dayFallout pattern is difficult to predictStrongly depends on terrain and meteorological conditionsFission products and other radioactive debris condense ontosolid and molten soil minerals (Particle size: mm)29 Methodology to Predict Fallout(cf. Glasstone Figure , Figure , and Table )30 Total-dose contours from early fallout after a surface burst with a total yield of 2 megatons and 1-megaton fission yield (15 mph effective wind speed).Source: Glasstone, Figure rads (10 Gy):Dose to (unprotected) humans at a distance of30 miles from explosion (in the direction of wind)Total area: about 200 square miles31 Estimated local (integrated) dose contours in rads at 96 hours after the BRAVO (15 Mt) test explosionSource: Glasstone, Figure : Ted Postol, lecture notes33 [I]t seems reasonable to assume that the destruction of, say, 25 percent of its population (55 million people) and more than two-thirds of its industrial capacity would mean the destruction of the Soviet Union as a national society.

9 Such a level of destruction would certainly represent intolerable punishment to any industrialized nation and thus should serve as an effective deterrent. Secretary of Defense McNamaraNovember 21, 1962 memo to President Kennedy3435 Conclusion / Epilogue36 Duck and Cover Federal Civil Defense Administration, 195137 The Day After ABC Television, November 19833839