Questions

1. What is the level of exposure for military personnel exposed to a nuclear test exercise in comparison to their annual dose?

2. Name at least three of the principal radioactive nuclides in nuclear fall-out ?

3. In which body organ does 90Sr, and where does 131I accumulate?

131I Fallout from Nevada Tests

High altitude wind distribution of fallout from selected Plumbbob tests

Hood & Stokes

Shasta & Galileo

St. Josephs County, Indiana

Test Series Average doses (rad) resulting from Collective doses (man.rad)

milk consumption all exposure routes milk cons. all exposure routes

GM (rad) GM (rad) GM (rad) GM (rad)

Ranger 1951 0.000 0.000 40. 76.

Buster Jungle 1951 0.000 0.001 81. 218.

Tumbler Snapper 1952 0.948 1.155 207935. 253403.

Upshot Knothole 1953 0.470 0.567 103099. 124325.

Teapot 1955 0.088 0.118 19301. 25883.

Plumbbob 1957 0.573 0.707 125717. 155118.

Underground 1961-1970 0.099 0.131 21680. 28834.

Collective dose is a measure of the total amount of effective dose multiplied by the size of the exposed population.

Fallout Radioactivity

90Sr (T1/2=28y) is stored in humanbone material because of its close chemical resemblance to calcium.

1 PBq=1015 Bq

Human Exposure from Nuclear Tests

External exposure: 95Zr,106Ru, 140Ba, 144Cs

Ingestion exposure: 90Sr, 131I, 140BaInhalation exposure: 54Mn, 55Fe, 95Sr,

125Sb, 137Cs

www.unscear.org/pdffiles/annexc.pdf

Average annual dose 360 mRem=3.6mSv

Nuclear Attack

Expectations

Grand Scale Nuclear Attack (war with other nuclear power)probability has declined with the demise of the Soviet Union – Chinahas not emerged as a comparable nuclear power but its arsenal is growing

Global Consequences of Nuclear War (nuclear winter)only possible in case of global nuclear conflict

Small Scale Nuclear Attack (terrorist incident)large scale attack with full nuclear warhead depends on availabilityof fissionable material. Most likely source former Central Asian Soviet Republics which had maintained a considerable stockpile.“Dirty bombs” are inconsequential, paranoia driven idea in mediaand politics.

Grand Scale Nuclear WarsWould include attacks on all major US cities withdisastrous consequences for population Immediatehigh death toll and extreme high rate on heat andradiation induced injuries and health problems.This, coupled with insufficient medical supportsystem will lead to complete collapse of civilianstructures. Presently low probability to take place.

Chesley Bonestell (1888-19860

Dooms Day Scenarios in the 1950ies

Widespread fearof an imminentnuclear attackwas reflected injournals, papers,books, and art.

Hypothetical Attack

Fallout patterns at near lethal levels7h after hypothetical attack.

Fallout patterns at near lethal levels48h after hypothetical attack.

with 223 bombs generating a total yield of 1453 Megatons. The radioactive fallout is spread according to the characteristic wind pattern and wind direction over the North American continent!

Medical Implications of Nuclear War, NRC 1986

Invasion USA

Mortality Probability 3.9 million people would be affected

Red 90% Dark Blue 40%

Lt Brown 80% Lt Purple 30%

Yellow 70% Dk Purple 20%

Green 60% Dk Pink 10%

Pale Blue 50% Lt Pink 1%

New York City – 250 kT Nuclear Bombwarhead of that size is onlyavailable in major arsenalsThe likelihood of a major nuclear attack on New Yorkof that scale is small.

New York City – 20 MT Nuclear Bomb

Considerably broader impactin shock wave and destruction

3,000 Rem*Distance: 30 milesLethal dose within hours10 years before area is safe

900 Rem*Distance: 90 milesLethal dose: 2 – 14 days

300 Rem*Distance: 160 milesExtensive internal damage

90 Rem*Distance: 250 milesNo immediate harmful effects, but decrease in white blood cells.2 – 3 years before considered ‘safe’.

*Based on 15 mph winds

Attack on Chicago

Dust & Debris

Environmental Impacts

Uplift of 0.1-0.33 Mt of dust per 1Mof TNT explosion! Details dependon soil and weather conditions.

Dust, Debris and Climate

Dust particles decrease visibility by scattering and absorbing sunlight.This affects the optical depth ·d for electromagnetic radiation. Smallerparticles reflect blue to UV light much stronger than larger particles whichscatter and reflect all UV, visible, and IR light equally.

Dust particles affect Earth's climate. They reflect sunlight, increasing thealbedo (reflection probability of sunlight) and thus cool Earth's surface.

Dust particles serve as in situ condensation nuclei and thus modify cloudamount, cloud distribution, and cloud properties. Dust particles may alsoinfluence precipitation amount, distribution, and frequency since theyenhance cloud condensation (rain maker technique).

Causes of Change• Forest Fires• Pyrotoxins• Dust from blasts• Soot from cities burning• Widespread ionizing radiation

Reduction of sun light follows absorption law:

eII 0 is absorption coefficient which depends sensitively on dust size and content, dust, aerosols, etc!

Temperature development due to absorption of sunlight in atmosphere

Temperature development after nuclear war of different scales

The study assumed 5000 Mt first strike with 0.1-0.33 Mt of dust per 1Mt of TNT exploded. The model estimates 225 Mt smoke emission and 960 Mt dust emission (≈ 960 Tg). The optical absorption parameter was calculated to: ≈ 4.5 indicating ~99% absorption!Drop in temperature by up to 40oC!

Impact on temperatures

Differences between Northern and Southern Hemisphere

Model predicts shut-down of vertical circulation

Carl Sagan on Nuclear Winter