an overview of the nuclear fuel cycle and radioactive materials industry chuck cain u.s. nuclear...

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?