4/2003 Rev 2 I.4.9d – slide 1 of 23 Session I.4.9d Part I Review of Fundamentals Module 4Sources of Radiation Session 9dFuel Cycle - Conversion IAEA Post Graduate Educational Course Radiation Protection and Safety of Radiation Sources

4/2003 Rev 2 I.4.9d – slide 2 of 23 Conversion

4/2003 Rev 2 I.4.9d – slide 3 of 23  Mills  Concentrate ores from ~1% to ~60%  Yellowcake (U 3 O 8 - really a mix of UO 2 and UO 3 )  Ammonium Diuranate (ADU – (NH 4 ) 2 U 2 O 7 )  Conversion Output is UF 6  Fluorine is used for two reasons:  Only one isotope  Physical properties are commercially viable Conversion

4/2003 Rev 2 I.4.9d – slide 4 of 23 Uranium Hexafluoride  Key compound in Nuclear Fuel Cycle  Solid for storage  Liquid for feeding/withdrawing  Gas for processing  Solid is white, dense, crystalline  Reacts with water vapor to produce toxic and corrosive hydrofluoric acid

4/2003 Rev 2 I.4.9d – slide 5 of 23 UF 6 + 2H 2 O  UO 2 F 2 + 4HF When UF 6 reacts with moisture in air, it creates deadly hydrogen fluoride (HF) Conversion Uranyl Fluoride Hydrofluoric Acid Chemical Hazard

4/2003 Rev 2 I.4.9d – slide 6 of 23 Uranium Compounds  U 3 O 8  UO 2  UF 4  UF 6  Ore – conversion - enrichment  UF 6  UO 2 F 2  UO 3  U 3 O 8  UO 2  Fuel fabrication “dry” process”  (NH 4 ) 2 U 2 O 7  2NH 3 + 2UO 3  Ammonium diuranate (ADU) crystals  2UO 4  2UO 3 + O 2  Precipitation of uranyl nitrate and hydrogen peroxide.

4/2003 Rev 2 I.4.9d – slide 7 of 23 Comparison of Dry and Wet Conversion DRY Process  Pretreatment  Prepared Feed and Calcination  Reduction (NH 3 )  Hydrofluorination  Fluorination  Distillation  Product Loading and Shipping WET Process  Digestion  Solvent Extraction  Evaporation/Concentrate  Denitration/Calcination  Reduction (H 2 in steam)  Hydrofluorination  Fluorination  Product Loading and Shipping

4/2003 Rev 2 I.4.9d – slide 8 of 23 Dry Fluoride Volatility Conversion Process  Pretreatment  Prepared Feed and Calcination  Reduction  Hydrofluorination  Fluorination  Distillation  Product Loading and Shipping

4/2003 Rev 2 I.4.9d – slide 9 of 23 Conversion

4/2003 Rev 2 I.4.9d – slide 10 of 23 Conversion

4/2003 Rev 2 I.4.9d – slide 11 of 23 Conversion

4/2003 Rev 2 I.4.9d – slide 12 of 23 Reduction

4/2003 Rev 2 I.4.9d – slide 13 of 23 Hydrofluorination

4/2003 Rev 2 I.4.9d – slide 14 of 23 Fluorination

4/2003 Rev 2 I.4.9d – slide 15 of 23 Distillation

4/2003 Rev 2 I.4.9d – slide 16 of 23 Product Loading and Shipping  UF 6 product is 99.99% pure  Packaged in 10 and 14 ton cylinders  Allowed to cool for 5 days to solidify  Overfill is the biggest safety concern  Product (source material) is shipped to the Gaseous Diffusion Plants for enrichment (special nuclear material)

4/2003 Rev 2 I.4.9d – slide 17 of 23 Conversion

4/2003 Rev 2 I.4.9d – slide 18 of 23 Wet Acid Digestion Conversion Process (SFC)  Nitric acid digestion of yellowcake  Dilute uranyl nitrate (UO 2 (NO 3 ) 2 )  Selective solvent extraction  Purified UO 2 (NO 3 ) 2 solution  Evaporation/concentration  Denitration/calcination  UO 3 (Orange oxide)  Reduction with H 2  UO 2 (Brown oxide)  Hydrofluorination  UF 4 (Green Salt)  Fluorination  UF 6

4/2003 Rev 2 I.4.9d – slide 19 of 23 Other Conversion Processes  British Process  Calcination of ammonium diuranate crystals by batch  (NH 4 ) 2 U 2 O 7  2NH 3 + H 2 O + 2UO 3  In the same furnace, the UO 3 is further reduced to UO 2 in the presence of hydrogen in a batchwise manner.

4/2003 Rev 2 I.4.9d – slide 20 of 23 Other Conversion Processes (cont)  French Process  Uranium peroxide is precipitated through the addition of hydrogen peroxide to an aqueous solution of uranyl nitrate in a batch process  UO 2 (NO 3 ) 2 6H 2 O +H 2 O 2  UO 4 2H 2 O  UO 4  2UO 3 + O 2 (Calcined)  UO 3 + NH 3  UO 2 (Reduction – ammonia 750  C).

4/2003 Rev 2 I.4.9d – slide 21 of 23 UF 6 Properties  UF 6 + 2H 2 O  UO 2 F 2 + 4HF  Any UF 6 leak into air will react with moisture and appear as a white cloud  When cooled to ambient temperatures, UF 6 is a solid at atmospheric pressures.  UF 6 cylinders are under a slight vacuum when allowed to reach ambient temperatures.  Any cylinder leak would tend to “self-seal” through the formation of UO 2 F 2 at the leak.

4/2003 Rev 2 I.4.9d – slide 22 of 23 Conversion Gore Oklahoma USA (closed)

4/2003 Rev 2 I.4.9d – slide 23 of 23 Conversion Uranium Hexafluoride Conversion Facilities CountryOwnerPlantCapacity (MTU/year) (MTU/year) RussiaRosatom Angarsk20,000 United StatesConverdynMetropolis, Illinois17,600 FranceCOMURHEX Pierrelatte 114,000 CanadaCamecoPort Hope, Ontario10,500 United KingdomSpringfieldsSpringfields, Lancashire6,000 Fuels Ltd Fuels Ltd RussiaRosatomEkaterinburg4,000 ChinaCNNCLanzhou3,000 FranceAreva NC Pierrelatte TU5350 BrazilIPENSão Paulo90 Total75,540