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Radiochemistry - The Integration of Physics and Chemistry - the Beginnings

Radiochemistry - The Integration of Physics and Chemistry - the Beginnings. - Klaproth Uranium discovered - Peligot Uranium isolated 1895 - Roentgen X - rays 1896 - Becquerel Radioactivity 1898 - The Curies Radium and Polonium 1899 - Rutherford Alpha & beta particles

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Radiochemistry - The Integration of Physics and Chemistry - the Beginnings

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  1. Radiochemistry - The Integration of Physics and Chemistry - the Beginnings • - Klaproth Uranium discovered • - Peligot Uranium isolated • 1895 - Roentgen X - rays • 1896 - Becquerel Radioactivity • 1898 - The Curies Radium and Polonium • 1899 - Rutherford Alpha & beta particles • 1904 - Rutherford & Soddy Theory of radioactivity • 1911 - Rutherford Model of the atom • 1913 - Bohr Model of the atom • Soddy Isotopes of elements

  2. Radiochemistry - The Integration of Physics and Chemistry - the Continuation 1918 - Aston Identifies isotopes of neon 1919 - Rutherford & Chadwick Artificial elemental transmutation 1932 - Chadwick Neutron Urey Isolates deuterium an isotope of hydrogen 1934 - Joliot-Curies Artificial radioactivity Fermi ‘Transuranium’ elements Noddack Suggests possibility of fission 1935 - Fermi Neutron moderation Dempster Discovery of U-235 1936 - Bohr Liquid drop model of nucleus 1938 - Hahn & Straussman Chemical verification of fission 1939 - Meitner & Frisch Explanation of Hahn’s results 1941 - Seaborg Plutonium

  3. Keeping nuclear transformations in the neighborhood β X U Number of neutrons α Th X is a “new” transuranium element Number of protons

  4. Hahn and StraussmanChemical Discovery of FissionBerlin, December 1938 n1 n1 o o Uranium compounds Ra (III) Neutron source Acid + Ra (III) Ra (III) soln BaCl2 carrier soln Ra (III) & Ba2+ soln Ra (III) soln + Ra (III) & Ba2+ soln H2CO3 soln Soln & BaCO3(s) Ra(III)CO3 + BaCO3(s) Ra(III)CO3 HBr Ra (III) & Ba2+ soln + Fractional crystallization Ra (III) & Ba2+ soln Could not separate Ra(III)from Ba !

  5. The Beginning of the Manhattan Project Albert Einstein and Leo Szilard Long Island, New York August 1939

  6. British MAUD Committee • Established April 1940 as a result of the Frisch-Peirerls Memo • Functioned under the ministry of Aircraft production • Final report completed July 1941 was most useful to the U.S. • Directed by Prof. G. P. Thomson, J.J.’s son Cambridge Birmingham Oxford Liverpool I.C.I. (fundamental (U-235 bomb) (Separation (fundamental (chemical nuclear properties) of U-235) nuclear properties) problems) Cockcrof Haworth Simon Chadwick Baxter Bragg Peirels Frisch Halban Fuchs Kowarski

  7. Seaborg’s diary entry on the discovery of element atomic number 94

  8. Seaborg’s discovery that element 94 undergoes fission

  9. Results of Neutron Interactions with Uranium and Plutonium Isotopes fission non-fission U-238 Pu-239 Neutron cross sections U-235 U-238 (slow) (fast) 25 ev 1 Mev Neutron energy

  10. Possible Routes to Fissionable MaterialsConsidered by U. S. in 1942 • Gaseous Diffusion • Electromagnetic Separation • Centrifugation • Liquid Thermal Diffusion U-235 Natural Uranium (99.3% U-238, 0.7% U-235) • Uranium-graphite reactor • Uranium-heavy water reactor Pu-239

  11. Uranium Metallurgy

  12. Methods Used to Separate U-235 from U-238

  13. Gaseous Diffusion K-25 Plant Oak Ridge

  14. Calutrons at the Y-12 Plant Oak Ridge

  15. Y-12 Electromagnetic Separation Plant Oak Ridge

  16. Production of weapons grade U-235Oak Ridge, TN - 1944-45 Natural uranium U-235 (0.7 %) UF6 (g) Product U-235 (90%) UF4 (s) S-50 Thermal Diffusion Y-12 Beta Calutrons U-235 (0.86%) UF6 (g) U-235 (15%) UF4 (s) K-25 Gaseous Diffusion Y-12 Alpha Calutrons U-235 (7%) UF4 (s)

  17. Production of Plutonium From Uranium in a Nuclear Reactor

  18. Fuel Fabrication • Prepare fissile material to fuel nuclear reactors.

  19. Naturally Occurring Uranium U-238 (99.3%) U-235 (0.7%) Hanford Irradiated Fuel U-238 (>98%) other radioactive isotopes including Pu-239 (<1%) U-235 (<1%) 4000 grams of irradiated uranium produce approximately 1 gram Pu-239

  20. Pu Recovery by Bismuth Phosphate Process • Pu is found in low concentrations (<250 ppm) in reactor products. • Weapons grade Pu must be chemically pure (< 1 part in 107 parts Pu). • The Pu recovery for total process was 95% with < 1 part impurity in 107. HNO3 Pu(s) + X(s) Pu4+(aq) + Xy+(aq) H2SO4 H3PO4 Pu4+(aq) + Xy+(aq) + Bi3+(aq) Pu3(PO)4(s) + Xy+(aq) + BiPO4(s) HNO3 Pu3(PO)4(s) + BiPO4(s) Pu6+(aq) + Bi3+(aq) oxid. agent H3PO4 Pu6+(aq) + Bi3+(aq) Pu6+(aq) + BiPO4(s) H2O2 reducing agent Pu6+(aq) PuO22+(aq) Pu(s) Plutonium was redissolved and further purified using LaF2 in place of BiPO4(s) X(s) = fission products or uranium; y+ = oxidation state

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