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An Overview ofthe Nuclear Fuel Cycle
and Radioactive MaterialsIndustry
Chuck CainU.S. Nuclear Regulatory Commission, Region IVArlington, Texas
Implementing LegislationAtomic 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 2005Authorizes NRC to regulate naturally
occurring material and accelerator-produced material
Agreement StatesThese 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 SweetwaterMine & Mill(Wyoming)
Atlas Mineralson Colorado Rivernear Moab, UT
Typical in situ Leach Well Field
TYPICAL SOLUTION FLOW PATTERNS
0 60' 120' 180' 240'
LEGEND
INJECTION WELL
PRODUCTION WELL
EXPECTED FLOW PATTERN
Yellowcake belt dryer
Yellowcake Product
Yellowcake is packaged into 55-gallon drums and prepared for shipment.
Facts About YellowcakeCan 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 UraniumThe 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
UF6
Yellowcake can be converted to uranium hexafluoride which has a triple point of 147° F
Honeywell, Metropolis, ILSequoyah Fuels, Gore, OK (closed)
Enrichment PlantsSince 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
UF6 is stored in cylinders. This one is rated at 14 tons.
Depleted UraniumDepleted 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 TechnologiesGas centrifuge
Louisiana Energy Services Areva
Laser separation
Fuel Fabrication
The enriched UF6 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 SecoISFSI
Yucca Mountain, Nevada
Also, Low-Level WasteContaminated 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)
Quantity of Radioactive Material
Unit of measurement - curies or becquerels
Half-LifeTime it takes for half of a radioactive
material to decayCobalt-60, 5 yearsUranium, millions of yearsSome materials decay with a half-life in
minutes or seconds, such as those for medical use.
Dose to RadiationUnits 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 LicensesSpecificGeneral (e.g., tritium exit signs)Exempt (e.g., smoke alarms)
“Materials” ApplicationsMedical (diagnosis, therapy)Academic Industrial (radiography, gauges,
petroleum industry)
Industrial Radiography
Radiography “cameras”
100 curies of iridium-192 in “pigtail”
Nuclear Gauges
Petroleum Well LoggingRadioactive 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, skindarkening and some blisteringis evident. Estimated exposure 22K – 30K rems.
Day 19 – Extensive blistering is apparent.
Day 24 – Blisters are breaking anddead skin is sloughing off,exposing raw tissue underneath.
Day 27 – Areas of obvious injurycontinue to grow larger,with no evidence of healing.Increasing pain in damagedareas.
Day 56 – Pain has increased until damaged tissues can no longer be exposed to air.Decision to perform skingrafts.
Day 102 – Extensive skin grafting complete. Deep tissue injury continues.
5 years – Loss of fingers; hands sensitive to heat and cold;additional amputationsmay 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 LicensedCertain jewelry itemsFiesta wareColeman lantern mantlesSmoke detectors
Remaining Questions?