ML12159A192
| ML12159A192 | |
| Person / Time | |
|---|---|
| Issue date: | 06/07/2012 |
| From: | Office of the Chief Human Capital Officer |
| To: | |
| References | |
| Download: ML12159A192 (89) | |
Text
Fuel Cycle Processes HRTD Human Resources Training & Development Seminar for ASLBP (G-114) April, 2011- slide 1 of 88
Objectives Briefly discuss properties of natural uranium Discuss the facilities and processes involved in the uranium and mixed oxide fuel cycle Discuss the uranium recovery process and identify its associated hazards Discuss the uranium conversion process and identify its associated hazards Seminar for ASLBP (G-114) April, 2011- slide 2 of 88
Objectives Discuss the uranium enrichment processes and their associated hazards Discuss the uranium fuel fabrication process and its associated hazards Briefly discuss the mixed oxide (MOX) fuel fabrication program Briefly discuss the Blended Low-Enriched Uranium (BLEU) project Seminar for ASLBP (G-114) April, 2011- slide 3 of 88
Properties of Natural Uranium Natural uranium consists of three isotopes:
Isotope % Abundance Half Life (years) 238U 99.284 4.5 billion 235U* 0.711 704 million 234U 0.005 245 thousand
- Must be enriched up to about 3-5% for commercial fuel Seminar for ASLBP (G-114) April, 2011- slide 4 of 88
Fuel Cycle Flow Diagram (old)
Weapons use > 20%
enriched U Seminar for ASLBP (G-114) April, 2011- slide 5 of 88
Fuel Cycle Flow Diagram (newer)
Almost half of LEU provided by downblended HEU Seminar for ASLBP (G-114) April, 2011- slide 6 of 88
Fuel Cycle Flow Diagram (newest)
Seminar for ASLBP (G-114) April, 2011- slide 7 of 88
Process Terminology Uranium recovery to extract (or mine) uranium ore, and concentrate (or mill) the ore to produce "yellowcake" Conversion of yellowcake into uranium hexafluoride (UF6)
Enrichment to increase the concentration of uranium-235 (U235) in UF6 Deconversion to reduce the hazards associated with the depleted uranium hexafluoride (DUF6), or tailings, produced in earlier stages of the fuel cycle Fuel fabrication to convert enriched UF6 into fuel for nuclear reactors Interim storage of spent nuclear fuel (ISFSI and spend fuel pools)
Recycling (or reprocessing) of high-level waste (currently not done in the U.S.)
Final disposition (disposal) of high-level waste Seminar for ASLBP (G-114) April, 2011- slide 8 of 88
Locations of Major US Fuel Cycle Facilities http://www.nrc.gov/info-finder/materials/fuel-cycle/
Uranium Recovery Operations Seminar for ASLBP (G-114) April, 2011- slide 10 of 88
Regulation of Uranium Recovery 10 CFR 40 - Domestic Licensing of Source Material Note: Although the title includes only Source Material, Part 40 also regulates Byproduct Material as it relates to the uranium recovery process, i.e., primarily mill tailings Source Material: (1) Uranium or thorium, or any combination thereof, in any physical or chemical form or (2) ores which contain by weight one-twentieth of one percent (0.05%) or more of: (i) Uranium, (ii) thorium or (iii) any combination thereof.
Source material does not include special nuclear material.
Depleted uranium (left over from uranium enrichment) is considered source material.
Byproduct material: Tailings or wastes produced by the extraction or concentration of uranium or thorium from any ore processed primarily for its source material content.
Seminar for ASLBP (G-114) April, 2011- slide 11 of 88
Regulation of Uranium Recovery NRC does not regulate conventional mining (regulated by Office of Surface Mining, Dept of the Interior, and the Agreement States),
but does regulate all milling activities (conventional or ISL)
Uranium Milling - means any activity that results in the production of byproduct material as defined in this part In-Situ Leaching (ISL) - a.k.a. In-Situ Recovery (ISR)
Most uranium is imported (>80% of 32,000 tons of U3O8 used per year)
Seminar for ASLBP (G-114) April, 2011- slide 12 of 88
Steps in Uranium Recovery (conventional mining and milling)
Seminar for ASLBP (G-114) April, 2011- slide 14 of 88
Typical U Open Pit Mine and Mill Facility Seminar for ASLBP (G-114) April, 2011- slide 15 of 88
Ore Crushed in Rolling Mills Seminar for ASLBP (G-114) April, 2011- slide 16 of 88
U Solvent Extraction Tanks at a Typical U Mill Seminar for ASLBP (G-114) April, 2011- slide 17 of 88
In Situ Recovery Milling In the in situ leaching (ISL) process, injection wells (1) pump a chemical solution typically sodium bicarbonate and oxygen into the layer of earth containing uranium ore. The solution dissolves the uranium from the deposit in the ground, and is then pumped back to the surface through recovery wells (2) and sent to the processing plant to be converted into uranium yellowcake. Monitoring wells (3) are checked regularly to ensure that uranium and chemicals are not escaping from the drilling area.
Seminar for ASLBP (G-114) April, 2011- slide 18 of 88
ISL Well Field Seminar for ASLBP (G-114) April, 2011- slide 19 of 88
Header House Seminar for ASLBP (G-114) April, 2011- slide 20 of 88
ISL Production Facility Seminar for ASLBP (G-114) April, 2011- slide 21 of 88
Resin Tanks U-bearing solution from injection wells is processed through a series of resin tanks in the Central Processing Plant or Satellite Plant to recover the uranium Seminar for ASLBP (G-114) April, 2011- slide 22 of 88
Shielded Resin Tanks Seminar for ASLBP (G-114) April, 2011- slide 23 of 88
ISL Stages of Production (See Handout on Uranium Recovery process)
Seminar for ASLBP (G-114) April, 2011- slide 24 of 88
Yellowcake packaged in 55-gallon Drums and prepared for shipment Seminar for ASLBP (G-114) April, 2011- slide 25 of 88
Radiological Hazards of U Recovery Ore dust and radon emissions from ore crushing, sorting, and storage Radiation Areas created from buildup of radium Radon gas and particulate daughters Yellowcake dust from drying and packaging area Windblown particulates and radon emission from the U mill tailings disposal area Soluble uranium compounds attack the kidneys (10 CFR 20.1201 (e) - 10 mg/week max intake)
Seminar for ASLBP (G-114) April, 2011- slide 26 of 88
Hazards of Tailings Seminar for ASLBP (G-114) April, 2011- slide 27 of 88
Tailings Disposal from Conventional Mill Seminar for ASLBP (G-114) April, 2011- slide 28 of 88
ISL Waste Water Disposal Seminar for ASLBP (G-114) April, 2011- slide 29 of 88
Uranium Recovery Facilities http://www.nrc.gov/info-finder/materials/uranium/index.html#licensed-facilitieshttp://www.nrc.gov/info-finder/materials/uranium/index.html#licensed-facilities
Uranium Recovery Sites Undergoing Decommissioning Pathfinder Lucky Mc Exxon Highland ANC Gas Hills Union Pacific Bear Creek PRI SR-HUP Umetco Gas Hills (active ISL)
Cogema (possible ISL restart)
Sweetwater (conventional mill standby)
Crow Butte (active ISL)
UNC Church Rock Rio Algom Pathfinder Shirley Basin (possible ISL restart)
Homestake Sequoyah Fuels Western Nuclear Split Rock http://www.nrc.gov/info-finder/decommissioning/uranium/index.html
Uranium mill closing may be temporary By Bruce Finley The Denver Post Posted: 08/19/2010 Cotter Corp. will dismantle its toxic waste ponds and buildings at a uranium mill south of Canon City, but it intends to keep its license from state regulators to operate at the site and may re-open, the vice president for operations said Thursday.
Accelerated efforts to close down contaminated facilities at the Superfund cleanup site are aimed at clearing a path for possible uranium processing in the future and do not indicate Cotter plans to leave the 2,600-acre site, vice president John Hamrick said.
"We can decommission parts of the facility without moving towards license termination,"
Hamrick said. "Our intention is ... to clear the path for new construction in the future."
No date has been set or plans submitted for that construction.
A new state law requires uranium mill operators to clean up existing messes before launching new projects. Cotter opposed that law and, before it was passed, warned that it could kill a proposed project to haul uranium from a mine in New Mexico by train and process it at the mill.
Recent Cotter letters to U.S. Environmental Protection Agency and Colorado Department of Public Health and Environment regulators indicated that Cotter was moving to close down facilities and no longer would test air for emissions of cancer-causing radon.
Uranium Conversion Seminar for ASLBP (G-114) April, 2011- slide 33 of 88
Regulation of U Conversion 10 CFR Part 40 - Domestic Licensing of Source Material Honeywell (old Allied-Signal) at Metropolis IL - only operating US plant Sequoyah Fuels at Gore OK - decommissioned Seminar for ASLBP (G-114) April, 2011- slide 34 of 88
Honeywell U Conversion Plant Converts feed material from around the globe, and also generates commercial fluorine gas.
Seminar for ASLBP (G-114) April, 2011- slide 35 of 88
U Conversion Conversion Input is yellowcake and fluorine Conversion Output is UF6 Fluorine is used for two reasons:
Only one isotope of fluorine Physical properties are commercially viable
- UF6 is the only uranium compound that exists as a gas at a suitable temperature Seminar for ASLBP (G-114) April, 2011- slide 36 of 88
U Conversion Packaged in 10- and 14-ton cylinders Allowed to cool for 5 days to solidify Overfill is the highest safety concern Product (source material) is shipped to the Gaseous Diffusion Plants for enrichment (special nuclear material)
Seminar for ASLBP (G-114) April, 2011- slide 37 of 88
UF6 Properties Seminar for ASLBP (G-114) April, 2011- slide 38 of 88
UF6 Properties Reacts with moisture (e.g., in air) and creates deadly hydrogen fluoride (HF)
UF6 + 2H2O > UO2F2 + 4HF Chemical Uranyl Fluoride Hazard Thousands of smoke detectors utilized throughout the conversion and enrichment plants to warn operators of UF6 release Seminar for ASLBP (G-114) April, 2011- slide 39 of 88
HF Severely Damages Skin Seminar for ASLBP (G-114) April, 2011- slide 40 of 88
HF Skin Damage Example Seminar for ASLBP (G-114) April, 2011- slide 41 of 88
Damage Largely Healed Seminar for ASLBP (G-114) April, 2011- slide 42 of 88
Sequoyah Fuels Accident In January 1986, a 14-ton cylinder was overfilled with liquid UF6 The operators did not know by how much the weight limits were exceeded Product draw-off stopped due to solidification of the UF6 as it cooled A supervisor ordered the operator to place the cylinder in a steam chest for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> About 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> into the heat-up, the cylinder failed catastrophically. One operator died Seminar for ASLBP (G-114) April, 2011- slide 43 of 88
Sequoyah Fuels in 1986 Site of the accident Seminar for ASLBP (G-114) April, 2011- slide 44 of 88
UF6 Cylinder at Sequoyah Fuels Seminar for ASLBP (G-114) April, 2011- slide 45 of 88
Damaged Cylinder and Steam Chest Seminar for ASLBP (G-114) April, 2011- slide 46 of 88
Rags Stuffed in the Breach in the Cylinder Seminar for ASLBP (G-114) April, 2011- slide 47 of 88
Washing Out the Residual UF6 Seminar for ASLBP (G-114) April, 2011- slide 48 of 88
Close-up View of the Breach in the Cylinder Seminar for ASLBP (G-114) April, 2011- slide 49 of 88
Accidental UF6 Release from Honeywell Occurred on December 22, 2003 Release of UF6 to offsite environment No injuries to workers Four members of public reported to the local hospital. One of these exhibited skin reddening and symptoms of low level exposure to HF Seminar for ASLBP (G-114) April, 2011- slide 50 of 88
Uranium Enrichment Seminar for ASLBP (G-114) April, 2011- slide 51 of 88
Oak Ridge Gaseous Diffusion Plant Former K-25 Site - in decommissioning since late 80s. Oak Ridge Reservation is listed by the EPA as a Superfund Site. Most of these buildings have been removed.
Seminar for ASLBP (G-114) April, 2011- slide 52 of 88
Paducah Gaseous Diffusion Plant Max enrichment of 5.5% since 2002 Seminar for ASLBP (G-114) April, 2011- slide 53 of 88
Portsmouth Gaseous Diffusion Plant On July 29, the NRC accepted an application from the United States Enrichment Corporation (USEC) dated June 28 to terminate operations under the Certificate of Compliance (GDP-2) at the Portsmouth Gaseous Diffusion Plant (70-7002) in Piketon, Ohio. The NRC interoffice staff from NMSS, NSIR, FSME, R-II and OGC determined that the submittal contained adequate information to begin a detail technical review. The staff is targeting the completion of its review by the end of September 2011.
Cold Standby since 2001 Seminar for ASLBP (G-114) April, 2011- slide 54 of 88
Regulations The GDPs are regulated under 10 CFR 76 Only Certified licensee. Recertifications are required under the Atomic Energy Act, as amended, and the Energy Policy Act of 1992 Certification allowed the NRC to take into account the baseline safety established by the plants during their extended operating history, rather than providing an initial justification for operation NRC certified the two GDPs; recertification is valid until December 31, 2013 Seminar for ASLBP (G-114) April, 2011- slide 55 of 88
Basic Theory Gaseous Diffusion uses molecular diffusion to separate the isotopes of uranium Three basic requirements are needed Combine uranium with fluorine to form Uranium hexafluoride (UF6) - conversion process Pass UF6 through a porous membrane Utilize the different molecular velocities of the two isotopes to achieve slight separation and, thus, enrichment Seminar for ASLBP (G-114) April, 2011- slide 56 of 88
Basic Theory Enrichment of 235U through one porous membrane (or barrier) is very minute Thousands of passes are required to increase the enrichment of natural uranium (0.711%) to a usable assay of 3 - 5% for use in commercial reactors Seminar for ASLBP (G-114) April, 2011- slide 57 of 88
Gas flow through a Stage Seminar for ASLBP (G-114) April, 2011- slide 58 of 88
Typical Enrichment Stage (Cascade)
Seminar for ASLBP (G-114) April, 2011- slide 59 of 88
Uranium Properties Uranium Isotope Percent
- 238U is most 100 abundant 10
- 234U increases with 1 enrichment U-238
- Watch activity ratios 0.1 U-235 0.01 U-234 0.001 0.0001 Nat Low Depl LEU DU Seminar for ASLBP (G-114) April, 2011- slide 60 of 88
Feed Cylinders Arriving at Plant Seminar for ASLBP (G-114) April, 2011- slide 61 of 88
Lifting a cylinder filled with solid UF6 Seminar for ASLBP (G-114) April, 2011- slide 62 of 88
A Whole Lot of DU!
Seminar for ASLBP (G-114) April, 2011- slide 63 of 88
Potential Hazards Primary overall hazard is a major UF6 release Liquid cylinder drop is most credible When UF6 reacts with water, it forms hydrofluoric acid Both corrosive and toxic Criticality accidents of special nuclear material (enriched U), with large radiation release Seminar for ASLBP (G-114) April, 2011- slide 64 of 88
Tickling the Dragons Tail Seminar for ASLBP (G-114) April, 2011- slide 65 of 88
Decrease in Radiation Dose with Distance from Criticality Accident ~ 3 x 1017 fissions 400 rad at 15 ft
- LD 50/60 (50% mortality) 9000 rad x (3.16/10)2
= 900 rad (Inverse Square law)
Seminar for ASLBP (G-114)
Mortality near 100% April, 2011- slide 66 of 88
Acute Radiation Damage to Hands Seminar for ASLBP (G-114) April, 2011- slide 67 of 88
View of Right Hand -
24 Days Post-Exposure Seminar for ASLBP (G-114) April, 2011- slide 68 of 88
View of the Torso 24 Days Post-Exposure Seminar for ASLBP (G-114) April, 2011- slide 69 of 88
Other Significant Hazards The primary fire hazard is the Lube Oil system Primary radiological hazard is exposure of operating personnel to a major UF6 release (HF)
Chemical hazards Over 600 separate chemicals used at the GDPs Seminar for ASLBP (G-114) April, 2011- slide 70 of 88
U Enrichment by the Gas Centrifuge Process Seminar for ASLBP (G-114) April, 2011- slide 71 of 88
Views of a Urenco Gas Centrifuge Cascade Seminar for ASLBP (G-114) April, 2011- slide 72 of 88
Current Gas Centrifuge (GC) Activities Louisiana Energy Services facility In June 2006, NRC issued license to LES to construct and operate the National Enrichment Facility in Lea County, NM - up to 5% U-235 enrichment The National Enrichment Facility is the first commercial facility in the United States to use gas centrifuge technology for enriching uranium Seminar for ASLBP (G-114) April, 2011- slide 73 of 88
Current Gas Centrifuge (GC) Activities USEC Facility NRC issued a 5-yr license to USEC in February, 2004 to construct and operate a U enrichment test and demonstration facility at Portsmouth GDP, Piketon, Ohio Facility is called the Lead Cascade and will have up to 240 full-scale centrifuges In 2007, NRC issued a license to USEC to construct and operate the American Centrifuge Plant, a full-scale U enrichment plant, at Portsmouth GDP . The application is currently under review. NRC issued its SER in 9/2006.
U-235 enrichment level would be up to 10% at ACP Seminar for ASLBP (G-114) April, 2011- slide 74 of 88
Laser Enrichment (AVLIS)
Atomic Vapor Laser Isotope Separation DOE tech.
U metal feed - no UF6 !
Seminar for ASLBP (G-114) April, 2011- slide 75 of 88
Laser Enrichment (SILEX)
Australian technology Separation of Isotopes by Laser Excitation Being developed by GE/Hitachi January, 2009: GE-Hitachi Global Laser Enrichment LLC submitted Environmental Report for plant to be located in Wilmington, NC Seminar for ASLBP (G-114) April, 2011- slide 76 of 88
Fuel Fabrication Seminar for ASLBP (G-114) April, 2011- slide 77 of 88
Objective of Fuel Fabrication Convert enriched UF6 into UO2 fuel pellets, suitable for use as fuel in a reactor NRC licenses fuel fabrication plants under 10 CFR Part 70 Seminar for ASLBP (G-114) April, 2011- slide 78 of 88
Fuel Fabrication Facilities Licensed By NRC Licensee Facility Typical Conversion Final Location Operations Process Product(s)
AREVA-L Lynchburg, VA LEU pellet loading, None LWR assemblies Assemblies AREVA-R Richland, LEU conversion, Dry LWR WA pellets, assemblies Assemblies, pellets BWX Technologies, Lynchburg, HEU/RTR fuels, Several HEU/RTR Inc. VA Downblend assemblies, LEU materials Global Nuclear Fuels- Wilmington, LEU conversion, Dry LWR Americas NC pellets, assemblies assemblies Nuclear Fuel Erwin, TN HEU/RTR fuels, Several HEU/RTR Services, Inc. Downblend assemblies, LEU materials Westinghouse Columbia, LEU conversion, Wet LWR (BNFL; Toshiba) SC pellets, assemblies (dry standby) assemblies NOTE: LEU is typically less than 5 wt % 235U.
HEU enrichment typically involves > 90 wt % 235U Seminar for ASLBP (G-114) April, 2011- slide 79 of 88
Westinghouse Facility Seminar for ASLBP (G-114) April, 2011- slide 80 of 88
UF6 Receipt, Handling and Storage UF6 received from enrichment facility in cylinders packed within NRC/DOT packaging Cylinders removed from package, weighed, and transferred to UF6 storage pad UF6 Cylinders Arriving at Facility Seminar for ASLBP (G-114) April, 2011- slide 81 of 88
Pellet Production Final machined pellets are typically about 0.5 inch in length & about 0.33 inch in diameter.
They are "dished" slightly on each end. End taper allows pellets to expand and contract through drastic temperature changes inside reactor without damaging fuel or cladding materials Seminar for ASLBP (G-114) April, 2011- slide 82 of 88
Fuel Rods and Assemblies Fuel Rods New Fuel Assembly Seminar for ASLBP (G-114) April, 2011- slide 83 of 88
Shipping Container Assembly is shock-mounted so that damage does not occur during transport to customer which is usually performed by truck Seminar for ASLBP (G-114) April, 2011- slide 84 of 88
Fuel Fabrication Hazards UF6 release Criticality Chemicals used in process Seminar for ASLBP (G-114) April, 2011- slide 85 of 88
Mixed Oxide (MOX)
Fuel Fabrication Objective is to remove 33-35 MT of surplus Pu from US and Russian weapons programs 5-8% Pu in pellets + ordinary LEUO2 pellets Pu and MOX powder more radiotoxic than ordinary UO2 pellets Seminar for ASLBP (G-114) April, 2011- slide 86 of 88
Mixed Oxide (MOX)
Fuel Fabrication Fabricate MOX fuel at Savannah River Site in SC Facility is operated by Shaw Areva MOX Services and owned by DOEs NNSA NRC issued a construction authorization on March 30, 2005 and construction started two years later License application accepted 12/2006 NRC staff to complete review/prepare Safety Evaluation -
12/2010 MOX fuel to be used in Duke Powers Catawba and McGuire NPPs Seminar for ASLBP (G-114) April, 2011- slide 87 of 88
Blended Low-Enriched Uranium (BLEU) Project NRC has approved 3 license amendments to authorize Nuclear Fuel Services (NFS), Erwin, TN to proceed with the BLEU project Project would convert about 33 metric tons of surplus highly enriched uranium from DOE into useable commercial reactor fuel for TVA Seminar for ASLBP (G-114) April, 2011- slide 88 of 88
Blended Low-Enriched Uranium (BLEU) Project NRC inspections of BLEU facilities already being performed Materials would be processed in uranyl nitrate, oxide conversion, and effluent processing buildings Quantities of low-enriched uranium would be stored onsite for future processing into fuel for TVA nuclear plants (i.e. Browns Ferry Nuclear Plant)
Seminar for ASLBP (G-114) April, 2011- slide 89 of 88
THE END Seminar for ASLBP (G-114) April, 2011- slide 90 of 88