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An Overview of the Nuclear Fuel Cycle and Radioactive Materials Industry Chuck Cain U.S. Nuclear Regulatory Commission, Region IV Arlington, Texas.

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Presentation on theme: "An Overview of the Nuclear Fuel Cycle and Radioactive Materials Industry Chuck Cain U.S. Nuclear Regulatory Commission, Region IV Arlington, Texas."— Presentation transcript:

1 An Overview of the Nuclear Fuel Cycle and Radioactive Materials Industry Chuck Cain U.S. Nuclear Regulatory Commission, Region IV Arlington, Texas

2 Implementing Legislation  Atomic Energy Act of 1954  established the Atomic Energy Commission (AEC)  Energy Reorganization Act of 1974  separated the peaceful uses regulatory function from the weapons function  established the NRC  weapons function eventually included in Department of Energy (DOE)

3 Energy Policy Act of 2005  Authorizes NRC to regulate naturally occurring material and accelerator- produced material

4 Agreement States  These are States that have agreements with NRC to regulate radioactive materials within their borders (except reactors)  All States in NRC Region IV are Agreement States except Montana, Wyoming, South Dakota, Idaho, Alaska, and Hawaii

5 Agreement State Map

6 Since 9/11…  …particular attention is paid to security and not only safety (user qualification and equipment)


8 Uranium Mining and Milling  Mining by conventional methods or by In-situ leaching  Ore is < 1% uranium  Mill extracts uranium from ore; rest is tailings  Mill product is uranium oxide (known as yellowcake) and is shipped in 55-gallon drums

9 The Sweetwater Mine & Mill (Wyoming)


11 Atlas Minerals on Colorado River near Moab, UT



14 Typical in situ Leach Well Field


16 Yellowcake belt dryer

17 Yellowcake Product Yellowcake is packaged into 55-gallon drums and prepared for shipment.


19 Facts About Yellowcake  Can be held in hands without harm.  A drum of yellowcake weighs about 1,000 pounds.  Natural uranium contains mostly uranium-238 (99.3%).  We want the U-235 which is only 0.7% of natural uranium.

20 Enriched Uranium  The next challenge is to enrich the uranium (increase the proportion of U-235)  Enrichment plants usually work by gaseous diffusion; therefore, the uranium must be converted to a gas.

21 Conversion Plants Produce UF 6  Yellowcake can be converted to uranium hexafluoride which has a triple point of 147° F  Honeywell, Metropolis, IL  Sequoyah Fuels, Gore, OK (closed)

22 Enrichment Plants  Since an atom of U-238 is larger than an atom of U-235, the atoms can be filtered at a gaseous diffusion enrichment plant.  Uranium must be enriched to ~10% to make nuclear fuel for a reactor.

23 Oak Ridge

24 Paducah Gaseous Diffusion Plant

25 UF 6 is stored in cylinders. This one is rated at 14 tons.



28 Depleted Uranium  Depleted uranium is a waste product of the enrichment process.  Depleted uranium is “depleted” in U-235 (less than 0.7% U-235).  DU can be used for purposes where a heavy mass is needed, such as military projectiles.



31 New Technologies  Gas centrifuge  Louisiana Energy Services  Areva  Laser separation

32 Fuel Fabrication  The enriched UF 6 is converted to a powdered chemical form and made into fuel pellets.





37 Spent Fuel  Eventually fuel elements become “poisoned” during the fission process and need to be replaced.  This is considered “high-level” waste.  There is still much good U-235 left in spent nuclear fuel.  The “poisons” (byproduct material) produced during the fission process are high-energy gamma emitters.

38 Spent fuel

39 Spent fuel stored in a fuel pool

40 What’s next for spent fuel?  Several options  store at reactor site in pool  store at site in Independent Spent Fuel Storage Installation (ISFSI)  burial at geological repository  reprocess (recycle) to separate the remaining good uranium from the waste

41 Arkansas Nuclear One ISFSI


43 Rancho Seco ISFSI

44 Yucca Mountain, Nevada

45 Also, Low-Level Waste  Contaminated or potentially contaminated items such as protective clothing, building materials, tools, etc.  Burial at licensed disposal site such as EnergySolutions (UT or SC), U.S. Ecology (WA)

46 Categories of Nuclear Materials  Source material – natural uranium and thorium  Special Nuclear Material (SNM) – enriched uranium, plutonium  Byproduct material – byproduct of the fission process in a reactor

47 Quantity of Radioactive Material  Unit of measurement - curies or becquerels

48 Half-Life  Time it takes for half of a radioactive material to decay  Cobalt-60, 5 years  Uranium, millions of years  Some materials decay with a half-life in minutes or seconds, such as those for medical use.

49 Dose to Radiation  Units of rems or sieverts  Radiation worker limit is 5 rems  Limit for a member of the public is 100 millirems

50 Uses of Radioactive Materials

51 Kinds of Licenses  Specific  General (e.g., tritium exit signs)  Exempt (e.g., smoke alarms)

52 “Materials” Applications  Medical (diagnosis, therapy)  Academic  Industrial (radiography, gauges, petroleum industry)

53 Industrial Radiography

54 Radiography “cameras”

55 100 curies of iridium-192 in “pigtail”

56 Nuclear Gauges





61 Petroleum Well Logging  Radioactive materials are installed in tools to characterize producing zones deep underground



64 Injury to hands caused by radiation exposure from radiography source

65 Day 14 – Medical attention first received; swelling, tenderness, skin darkening and some blistering is evident. Estimated exposure 22K – 30K rems.

66 Day 19 – Extensive blistering is apparent.

67 Day 24 – Blisters are breaking and dead skin is sloughing off, exposing raw tissue underneath.

68 Day 27 – Areas of obvious injury continue to grow larger, with no evidence of healing. Increasing pain in damaged areas.

69 Day 56 – Pain has increased until damaged tissues can no longer be exposed to air. Decision to perform skin grafts.

70 Day 102 – Extensive skin grafting complete. Deep tissue injury continues.

71 5 years – Loss of fingers; hands sensitive to heat and cold; additional amputations may be required.

72 Another Radiation Exposure Case  Warehouse worker finds radiography source on floor after radiographer leaves  Worker places source pigtail in back pocket and asks secretary to call radiography company to come pick it up

73 100 curies of iridium-192 in “pigtail”




77 Radioactive Materials Not Licensed  Certain jewelry items  Fiesta ware  Coleman lantern mantles  Smoke detectors

78 Remaining Questions?

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