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Uranium Enrichment. Nuclear Bomb Test. Little Boy. Reactor Core. Why Separate?. Must Separate Lighter U 235 from U 238 Only U 235 is fissionable Necessary to produce reactor fuel which is 3.6% U 235 Weapons grade is 90% U 235.
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Uranium Enrichment Nuclear Bomb Test Little Boy Reactor Core
Why Separate? • Must Separate Lighter U235 from U238 • Only U235 is fissionable • Necessary to produce reactor fuel which is 3.6% U235 • Weapons grade is 90% U235 Lead container supposedly containing stolen weapons grade Uranium Billet of highly enriched U235
Uranium Enrichment Centrifuges • Uses UF6 gas(Uranium Hexafluoride) Solid UF6 in vial
How Gas Centrifuge Works Originally developed in Russia by Austrian scientist
Gas Centrifuge Details • The centrifugal forces push the heavier uranium 238 (U-238) closer to the wall of the rotor than the lighter U-235. • The gas closer to the wall becomes depleted in U-235 whereas the gas nearer the rotor axis is enriched in U-235. • The arrows in the first illustration depict the gas flowing within the rotor. • The gas flow can be produced by a temperature gradient over the length of the centrifuge. UF6 depleted in U-235 flows upwards adjacent to the rotor wall, while UF6 enriched in U-235 flows downwards close to the axis. The two gas streams are removed through small scooped pipes, called "scoops."
Spin 50,000 to 70,000 RPM • On magnetic bearings • Run ten years without attention • Low power use • Give 1,000,000 g’s • 10 to 20 stage cascade needed to get 3.6% U235 from 0.7% natural occurring
Gaseous Diffusion Process • Passes UF6 gas repeatedly through porous barriers with very tiny holes barely big enough for a molecule to squeeze through • Lighter U235 squeezes through more easily Paducah, Kentucky Gaseous Diffusion Plant
More On Gaseous Diffusion • Original process used in WWII at Oak Ridge, Tenn. facility • Much more expensive to operate than centrifuges • Needs up to 1400 stages to get reactor grade fuel Oak Ridge K25 plant begun in 1943
Uranium Enrichment Capacity • France diffusion 10,800 • Germany-Netherlands-UKcentrifuge 5,850 • Japancentrifuge 900 • USAdiffusion 8,000 • Russiacentrifuge 20,000 • China mostly centrifuge 1,000-13000 • Pakistancentrifuge 5
Laser Process • Newer process under development in Australia promises to be cheaper • Called SILEX • Licensed by US • Details are secret