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

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)

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

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

Agreement State Map

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

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

The Sweetwater Mine & Mill (Wyoming)

Atlas Minerals on Colorado River near Moab, UT

Typical in situ Leach Well Field

Yellowcake belt dryer

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

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.

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.

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)

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.

Oak Ridge

Paducah Gaseous Diffusion Plant

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

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.

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

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

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.

Spent fuel

Spent fuel stored in a fuel pool

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

Arkansas Nuclear One ISFSI

Rancho Seco ISFSI

Yucca Mountain, Nevada

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)

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

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

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.

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

Uses of Radioactive Materials

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

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

Industrial Radiography

Radiography “cameras”

100 curies of iridium-192 in “pigtail”

Nuclear Gauges

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

Injury to hands caused by radiation exposure from radiography source

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

Day 19 – Extensive blistering is apparent.

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

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

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

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

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

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

100 curies of iridium-192 in “pigtail”

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

Remaining Questions?