Radiation

1. Radiation ENGR302I

2. Electromagnetic Radiation • Radar, radio, and TV (transparent) • Microwave (Rotation of molecule) • Visible, UV (Vibration, absorbed by skin) • X-ray and gamma-ray (Ionization, nearly transparent, but highly energetic)

3. Ionizing Radiation • Ionizing radiations are: • X-ray • Alpha particles (helium nuclei) • Beta rays (electrons) • Gamma rays • Neutrons and Protons • Effects on humans are: • Damage DNA • Interference with normal cells

4. Half-Life • Half Lives • Uranium-235 0.7 billion years • Plutonium-239 24,360 years • Cesium-137 30 years • Strontium-90 28.8 years • Iodine-131 8.04 days • N/N0=1/1,000 10 half-lives • N/N0=1/1,000,000 20 half-lives • N/N0=1/1,000,000,000 30 half-lives

5. Biological Half-life • Radioactive material within a living cell: • Radioactive decay • Normal biological decay • Isotope iodine-125 • Non-biological half-life 60 days • Biological half-life 38 days • Isotope carbon-14 • Half-life 5000 years (essentially constant during one’s life time. • Carbon-dating

6. Units of Radiation • Source • Becquerel, Curie • Absorbed • rad (radiation adsorbed dose) • Human Biological Damage • rem (roentgen equivalent man) • For x-ray and gamma-ray 1 rem=1 rad

7. Nuclear Waste Depositories • Permanent subterranean • Entombment under the sea • Nuclear transmutation • Storage under polar caps • Other less serious proposals

8. Permanent Storage • Storage sites must be • Geographically stable with no flowing ground water for tens of thousands of years • 100 sites are designated as “temporary” storage sites • Permanent site (2010)– Yucca Mountain (Nevada – Near a young volcano and active fault line), Carlsbad (New Mexico - Oozing brine could cause steel brines to corrode) • Transporting nuclear wastes to these facilities is also a problem • NIMBY Syndrome Listen to NPR’s All Things Considered 2/22/02 NPR 2/5/02

9. Atom Bomb

10. Hydrogen Bombs • Isotopes of hydrogen and deuterium are fused to produce helium • No limits to the explosive power • US tested one with the explosive power of 68,000,000 tons of TNT • Consequences are horrifically unclear • Nuclear Winter, Worldwide famine

11. Weapon Design • Conventional vs. Nuclear Bombs • The A-Bomb • Critical mass • Dirty Bombs • Depleted Uranium • The H-Bomb (thermonuclear) • Neutron Bombs • Thermonuclear Bunker Busters

12. 1-Megaton Blast Distance from Ground zero • 1 mile • Over-pressure: 43 psi • Winds: 1700 mph • Many Humans Killed • 2 miles • Over-pressure: 17 psi • Winds: 400 mph • Humans battered to death; lung hemorrhage; eardrums ruptured; Heavy machinery damaged • 5 miles • Over-pressure: 4psi • Winds: 130 mph • Bones fractured; All trees down; Buildings flattened • 20 miles • Over-pressure: Below 1 psi • Winds: Below 35 mph • Many broken windows

13. Effects • Short term (somatic, massive , direct) • Fast growing cells are most susceptible to ionizing radiation • Bone marrow cells (making blood cells) • Ovaries, testes, lenses of the eyes • Cancer cells grow faster than normal cells so they are treated with radiation • Effects are • Reddening of the skin, drop in the white blood cells, nausea, vomiting, hair loss, bleeding, and death • Long term (chronic, low dose, indirect) • Chromosome (DNA) damage - cancer

14. Nuclear Arm Treaties Listen to NPR’s all thing Considered 2/22/02 Listen to NPR’s all thing Considered 5/13/02

15. Sources of Exposure • Non-ionizing radiation • Natural • UV from the sun • Man-made • UV from tanning machines • Ionizing radiation • Natural • High frequency UV • Intercontinental flights (cosmic rays) • Soil and rocks • Radon (radioactive decay of uranium in soil) • Man-Made • Dental and chest x-rays • Nuclear Medicine (Cobalt-60) • Nuclear reactors

16. Shock Effects Thermal Effects Radiation Effects Consequences of Nuclear Wars…

17. Nuclear Agency • US Department of Energy (DoE) • Nuclear Weapons Research • Licensing the nuclear reactors • Nuclear Waste • US Environmental Protection Agency (EPA) • Set exposure limits and standards • Cleanup of contaminated areas • US Nuclear Regulatory Commission (NRC) • Source material (uranium and thorium) • Enriched material (enriched uranium,, plutonium) • Dose limits for radiation medicine • Implementing EPA Standards • UN International Atomic Energy Commission (IAEC) • Verify through inspection that States comply with their commitments under the Non-Proliferation Treaty. • Nuclear Technology Transfer • Assist members in the planning peaceful nuclear programs

18. Public Exposure • Background 100 mrem • Medical 50 mrem • Radon 200 mrem • Nuclear reactors 10 mrem Total 360 mrem Ref: Nuclear Regulatory Commission

19. How much radiation do you receive?

20. Exposure Limit (EPA/NRC) • 125 mrems every three months (500 mrems per year) • Higher for nuclear reactor personnel (5000 mrem per year)

21. American Guinea pigs • In 1986, The Between 1940 and 1970, the US Government conducted radiation experiments on 695 human subjects without their knowledge. • In 1994, Energy secretary Hazel O’Leary declassified millions of pages of documents. As a result • Congress approved Radiation Exposure Compensation Act ($50,000 for residence who lived downwind from certain nuclear tests and later developed cancer) • $75000 for soldiers who developed cancer after participating in above ground nuclear war tests • $150,000,000 for residents of Martial Islands who became ill after 1940s-1950s tests

22. Regulation (Continued) • 1980 – Low-Level Radioactive Waste Policy Act • “Encourages” neighboring states to cooperate on reaching agreement on waste disposal in their “compact” and choose appropriate sites for disposal. • 1985 – Nuclear Waste Policy Act • Disposal of high-level nuclear waste is at the hands of Federal Government, while authorizing states and Native American tribes to participate n the selection of appropriate permanent repository site.

23. Internet Resources • Radiation and Health Physics (www.sph.umich.edu/group/eih/UMSCHPS/Sources.htm) Nuclear Regulatory Commission (www.nrc.gov)