Uranium EnrichmentUranium Enrichment

Reactor Core

Nuclear Bomb Test

Little Boy

Why Separate?Why Separate?

Must Separate Lighter UMust Separate Lighter U235235 from U from U238238

Only UOnly U235235 is fissionable is fissionableNecessary to produce reactor fuel which is Necessary to produce reactor fuel which is

3.6% U3.6% U235235

Weapons gradeWeapons grade is 90% U is 90% U235235

Lead container supposedly containing stolen weapons grade Uranium Billet of highly enriched U235

Uranium Enrichment CentrifugesUranium Enrichment Centrifuges

Uses UFUses UF6 6 gasgas (Uranium (Uranium

Hexafluoride)Hexafluoride)Solid UF6 in vial

How Gas Centrifuge Works

Originally developed in Russia by Austrian scientist

Gas Centrifuge DetailsGas Centrifuge Details The centrifugal forces push the heavier The centrifugal forces push the heavier

uranium 238 (U-238) closer to the wall of the uranium 238 (U-238) closer to the wall of the rotor than the lighter U-235. rotor than the lighter U-235.

The gas closer to the wall becomes depleted The gas closer to the wall becomes depleted in U-235 whereas the gas nearer the rotor in U-235 whereas the gas nearer the rotor axis is enriched in U-235axis is enriched in U-235..

The arrows in the first illustration depict the The arrows in the first illustration depict the gas flowing within the rotor. gas flowing within the rotor.

The gas flow can be produced by a The gas flow can be produced by a temperature gradient over the length of the temperature gradient over the length of the centrifuge. UF6 depleted in U-235 flows centrifuge. UF6 depleted in U-235 flows upwards adjacent to the rotor wall, while UF6 upwards adjacent to the rotor wall, while UF6 enriched in U-235 flows downwards close to enriched in U-235 flows downwards close to the axis. The two gas streams are removed the axis. The two gas streams are removed through small scooped pipes, called through small scooped pipes, called "scoops." "scoops."

Spin 50,000 to 70,000 RPMSpin 50,000 to 70,000 RPMOn magnetic bearingsOn magnetic bearingsRun ten years without attentionRun ten years without attentionLow power useLow power useGive 1,000,000 g’sGive 1,000,000 g’s10 to 20 stage cascade needed to get 10 to 20 stage cascade needed to get

3.6% U3.6% U235235 from 0.7% natural occurring from 0.7% natural occurring

Urenco Plant, UKUrenco Plant, UK

Gaseous Diffusion ProcessGaseous Diffusion Process

Passes UFPasses UF66 gas gas

repeatedly through repeatedly through porous barriers with porous barriers with very tiny holes barely very tiny holes barely big enough for a big enough for a molecule to squeeze molecule to squeeze throughthrough

Lighter ULighter U235235 squeezes squeezes

through more easilythrough more easilyPaducah, Kentucky Gaseous Diffusion Plant

Control Center of Paducah PlantControl Center of Paducah Plant

Gaseous Diffusion Plant in FranceGaseous Diffusion Plant in France

More On Gaseous DiffusionMore On Gaseous Diffusion

Original process used Original process used in WWII at Oak in WWII at Oak Ridge, Tenn. facilityRidge, Tenn. facility

Much more expensive Much more expensive to operate than to operate than centrifugescentrifuges

Needs up to 1400 Needs up to 1400 stages to get reactor stages to get reactor grade fuelgrade fuel

Oak Ridge K25 plant begun in 1943

Portsmouth, Ohio Diffusion PlantPortsmouth, Ohio Diffusion Plant

Uranium Enrichment CapacityUranium Enrichment Capacity

France diffusion 10,800France diffusion 10,800Germany-Netherlands-UKcentrifuge 5,850Germany-Netherlands-UKcentrifuge 5,850Japancentrifuge 900Japancentrifuge 900USAdiffusion 8,000USAdiffusion 8,000Russiacentrifuge 20,000Russiacentrifuge 20,000China mostly centrifuge 1,000-13000China mostly centrifuge 1,000-13000Pakistancentrifuge 5Pakistancentrifuge 5

Laser ProcessLaser Process

Newer process under Newer process under development in development in Australia promises to Australia promises to be cheaperbe cheaper

Called SILEXCalled SILEX Licensed by USLicensed by US Details are secretDetails are secret

Bushehr, Iran Nuclear PlantBushehr, Iran Nuclear Plant

What is this?What is this?