Radiochemistry - The Integration of

Physics and Chemistry - the Beginnings 1789- Klaproth Uranium discovered

1841- 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

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

XU

Th

Number of protons

Nu

mb

er o

f n

eutr

on

s

α

β

X is a “new” transuranium element

Keeping nuclear transformations in the neighborhood

Hahn and StraussmanChemical Discovery of Fission

Berlin, December 1938

Neutron source

Uranium compounds

Ra (III)

Ra (III) +Acid

Ra (III)soln

+BaCl2

carriersoln

Ra (III) &Ba2+ soln

Ra (III) &Ba2+ soln

Ra (III)soln

H2CO3

solnSoln &BaCO3(s)Ra(III)CO3

BaCO3(s)Ra(III)CO3

+

HBr+ Ra (III) &

Ba2+ soln

Ra (III) &Ba2+ soln

Fractionalcrystallization Could not separate

Ra(III) from Ba !

n1on1

o

The Beginning of the Manhattan Project

Albert Einstein and Leo SzilardLong Island, New York

August 1939

•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

British MAUD Committee

Cambridge Birmingham Oxford Liverpool I.C.I.(fundamental (U-235 bomb) (Separation (fundamental (chemicalnuclear properties) of U-235) nuclear properties) problems)

Cockcrof Haworth Simon Chadwick BaxterBragg Peirels FrischHalban FuchsKowarski

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

Seaborg’s discovery that element 94 undergoes fission

Neu

tron

cro

ss s

ecti

ons

fission

non-fissionU-238

U-238

U-235

Pu-239

Neutron energy25 ev 1 Mev(slow) (fast)

Results of Neutron Interactions with Uranium and Plutonium Isotopes

Possible Routes to Fissionable Materials

Considered by U. S. in 1942

Natural Uranium(99.3% U-238, 0.7% U-235)

•Gaseous Diffusion•Electromagnetic Separation•Centrifugation•Liquid Thermal Diffusion

U-235

•Uranium-graphite reactor•Uranium-heavy water reactor

Pu-239

Uranium MetallurgyUranium Metallurgy

Methods Used to Separate U-235

from U-238

Gaseous DiffusionK-25 Plant

Oak Ridge

Calutrons at the Y-12 Plant

Oak Ridge

Y-12 Electromagnetic Separation Plant

Oak Ridge

Production of weapons grade U-235Oak Ridge, TN - 1944-45

Natural uraniumU-235 (0.7 %)

UF6 (g)

U-235 (0.86%)UF6 (g)

U-235 (7%)UF4 (s)

ProductU-235 (90%)

UF4 (s)

U-235 (15%)UF4 (s)

S-50Thermal Diffusion

K-25Gaseous Diffusion

Y-12Alpha Calutrons

Y-12Beta Calutrons

Production of Plutonium From Uranium in a

Nuclear Reactor

Fuel Fabrication

• Prepare fissile material to fuel nuclear reactors.

Naturally Occurring Uranium

U-235 (0.7%)

U-238 (99.3%)

Hanford Irradiated Fuel

U-235 (<1%) other radioactive isotopes including Pu-239 (<1%)

U-238 (>98%)

4000 grams of irradiated uranium produce approximately 1 gram Pu-239

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.

Pu(s) + X(s) HNO3 Pu4+(aq) + Xy+(aq)H2SO4

Pu4+(aq) + Xy+(aq) + Bi3+(aq) Pu3(PO)4(s) + Xy+(aq) + BiPO4(s)

Pu3(PO)4(s) + BiPO4(s)HNO3

oxid. agentPu6+(aq) + Bi3+(aq)

Pu6+(aq) + Bi3+(aq)

H3PO4

H3PO4 Pu6+(aq) + BiPO4(s)

Pu6+(aq)H2O2 PuO2

2+(aq) Pu(s)reducingagent

X(s) = fission products or uranium; y+ = oxidation state

Plutonium was redissolved and further purified using LaF2 in place of BiPO4(s)

Inside Hanford T Plant

Little Boy - Hiroshima - 0815, August 6, 1945

Size: 10 ft long Weight: 8.900 lbs. (132 lbs >90% U-235)

(~ 2lbs underwent fission)Height of blast: 1900 ft.Yield: 15 - 16 Kt TNTCasualties ~ 100,000 immediate deaths

~ 200,000 total deaths

Fat Man - Nagasaki - 1102, August 9, 1945

Size: ~ 10.5 ft long, 5ft. DiameterWeight: 10,300 lbs.. (12 lbs.. Pu-239 of which

~ 2 lbs. underwent fission)Height of blast: 1650 ft.Yield: 22 Kt of TNTCasualties: ~70,000 immediate deaths

~140,000 total deaths

Steps in Producing a Nuclear Weapon

Mining, milling, and refining

Mining, milling, and refining

Isotope separation(enrichment)

Isotope separation(enrichment)

Fuel and target fabrication

Fuel and target fabrication

Reactor operationsReactor operationsChemical

SeparationsChemical

Separations

Componentfabrication

Componentfabrication

TestingTesting

WeaponsoperationsWeapons

operations

Fuel rod fabrication plant in Yongbyon, North Korea

Map of DPRK Nuclear Sites

http://alsos.wlu.edu

http://www.chemcases.com/2003version/nuclear/index2.htm