Environmental Science ENVS 1401402

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Environmental ScienceENVS 1401-402 404Dr.
Thieme

• 20th Lecture Nuclear, Biological,
• and Chemical Contamination
• Current Legislation

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Atomic Radiation

• 1896 Hans Becquerel discovers radiation given
  off by minerals that contain Uranium
• 1898 Ernest Rutherford experiments with
  radiation and hypothesizes that it is caused by
  emission of high-energy particles from atomic
  nuclei
• 1905 Albert Einstein writes the equation
  predicting a particles energy from its mass (E
  mc2)

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Nuclear Reactions

• 1938 Hahn and Strassman bombard Uranium atoms
  with neutrons and split the atom, producing
• smaller nuclei of Ba and Kr
• charged particles
• Military applications of atomic energy were
  recognized by both scientists and politicians
  fighting World War II

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Nuclear fission chain reaction for 235U
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Scientific Refugees

• 1938 News of the splitting of the atom was
  conveyed to Niels Bohr in Copenhagen.
• (A Jewish former colleague of Hahn, Lise
  Meitner, had a nephew working for Bohr, Otto
  Frisch)
• 1938 Bohr informs physicists convening in
  Washington, D.C. of "chain reaction"
• 1940 Frisch flees the Nazi invasion of Denmark,
  moving to Britain and prepares an outline of how
  to build a practical fission bomb

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Manhattan Project

• 1939 Albert Einstein writes to President
  Franklin Delano Roosevelt that "extremely
  powerful bombs" can be produced using a nuclear
  fission chain reaction.
• (Another refugee scientist, Leo Szilard, is
  credited with persuading Einstein to write the
  letter.)
• October, 1939 FDR replies to Einstein that a
  government committee had been established to
  study uranium.

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Manhattan Project

• 1939 Scientific team first convened in New York
  City, where physicists Enrico Fermi and Leo
  Szilard were experimenting with fission chain
  reactions.
• Fermi and Szilard used graphite to slow down, or
  moderate, the neutrons coming from the fission
  reaction, increasing the probability of their
  causing additional fissions in sustaining the
  chain reaction. 

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Manhattan Project

• 1945 In July, the first atomic bond is exploded
  in the desert at Alamagordo, New Mexico
• In August, the United States dropped atomic bombs
  on the cities of Hiroshima and Nagasaki,
  precipitating the surrender of Japan at the end
  of World War II.

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Radioactive Decay

• Atoms change from one element to another element,
  gaining or losing protons and neutrons in their
  nuclei
• Radiation is emission of charged particles, which
  occurs at a constant rate
• 235U decays to 207Pb
• 238U decays to 206Pb

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Uranium Isotope "Enrichment"

• 238U
• 235U
• 234U

• 99.28
• 0.71
• lt0.01

(Abundance in Uranium ore)

• Both weapons production and energy production
  require the "enrichment" of Uranium
• For nuclear power plants, 235U increased to 3.
• For atomic bombs, increased to 20.

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Plutonium

• Pu atomic number is 94
• produced in 1941 at the University of California
  at Berkeley by bombarding uranium atoms with
  deuterium
• Glenn Seaborg and his graduate student, Arthur
  Wahl with radiochemist Joseph W. Kennedy
• 239Pu undergoes further fission, which provides
  used in some weapons designs as well as the
  proposed "breeder" reactor for power plants

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Uranium Reserves

• 20.4
• 18.2
• 10.6
• 9.9
• 8.9

• Australia
• Kazakhstan
• United States
• Canada
• South Africa

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Nuclear Power

• 1954 Atomic Energy Act
• development, use, and control of atomic energy
  shall be directed so as to
• promote world peace
• improve the general welfare
• increase the standard of living
• strengthen free competition in private enterprise
• establishes the Nuclear Regulatory Commission
  (NRC) with authority of production and disposal
  of radioactive materials
• Section 274 provides that the NRC may transfer
  some control to states

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Nuclear Waste

• 1980 Nuclear Waste Policy Act
• Each state is reponsible for its own waste
• Facilities for Disposal are to be constructed by
  1996
• Currently there are only three (3)
• Hanford (Washington)
• Savannah River (South Carolina)
• Envirocare (Utah)

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Fritz Haber
1909 produces ammonia in the laboratory from N2
and H2 at a temperature of 1000 C with Fe as
catalyst
("Haber-Bosch process" is still fundamental to
fertilizer and other chemical factories) 1914
assists German war effort by manufacturing gun
cotton 1915 directs the first gas attack at front
line 1916 becomes chief of new Chemical Warfare
Service
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"Gassed" by John Singer Sargent
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Haber's Poison Gases

• Chlorine (ClO2) highly irritating to
  respiratory system but not fatal
• launched toward enemy trenches with large blowers

Phosgene (COCl2) affects nervous system and was
first synthesized by Sir Humphrey Davy in 1912

• "Mustard" gas complex chlorinated hydrocarbon
• Cl-CH2-CH2-S-CH2-CH2-Cl

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Poisons, Agricultural Chemicals

• 1947 Federal Insecticide, Fungicide, and
  Rodenticide Act (FIFRA)
• regulates the effectiveness of pesticides
• later amended as pesticides have been controlled
  or banned
• DDT banned
• 1974 Aldrin and Dieldrin banned

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Poisons, Agricultural Chemicals

• 1954 Pesticide Chemicals Amendment (Miller
  Amendment) to the Food, Drug, and Cosmetics Act
  (FDCA) of 1938
• 1958 Delaney Clause added to FDCA
• - canned or processed foods must not
  contain chemicals that cause cancer in test
  animals
• 1988 EPA permits exceptions in which chemicals
  only cause "negligible risk" of one case of
  cancer in 70 years or 1 million people

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Poisons, Agricultural Chemicals

• 2005 Pest Management and Fire Suppression
  Flexibility Act
• amends the Water Pollution Control Act to waive
  permit requirements for
• use of pesticide approved under FIFRA
• use of fire retardant, chemical, or water for
  fire suppression, control, or prevention
• silviculture activities
• eradication of a plant pest or noxious weed using
  a "biological control organism"

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Genetically Modified (GM) Organisms

• 1992 Biosafety Protocol (United Nations
  Convention on Biological Diversity)
• species procedures for handling and use of
  genetically modified (GM) organisms
• 1999 The European Union (EU) passed a moratorium
  on GM organisms, commonly violated

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