1. Depleted Uranium Hexafluoride (DUF6 ) Storage, Conversion, and Management in the U.S.
Gerald G. Boyd
Assistant Manager for Environmental Management
U.S. Department of Energy
Oak Ridge Operations
Presented at the
Russian-American Workshop on Management of Depleted Uranium
The US DOE uranium enrichment tails (DUF6) management program consists of 3 parts:
1. Cylinder storage, surveillance and maintenance
2. Conversion of the DUF6 into a more chemically stable form, and
the DU Uses R&D Project.
Jon Haire will describe the DU Uses R&D Project, in detail, during a presentation later today
There is not much that can be said about the DUF6 conversion plant contract. The awarding of that RFP is being protested by the losers. Two slides are given herein regarding part 2.
Gerald, this leaves you discussing primarily, part 1. Lots of pictures are given describing our storage, surveillance, and maintenance tasks. The cost to DOE of part 1 of the DUF6 Management Program is about $15/yr.
December 9–10, 2002
Moscow, Russia

2. Depleted Uranium (DU) Is a Legacy of Uranium Enrichment
This slide is just to remind everyone of where DUF6 came from…it is a by-product, the “tails” of uranium enrichment facilities.

3. Worldwide DU Inventory*
Inventory (MTU)
Storage form
Enricher
United States
France (COGEMA and Eurodif)
Urencoa
United Kingdom (BNFL)
Russia
Japan
Republic of Korea
China
480,000
190,000
16,000
30,000
460,000
10,000
200
2,000
UF6
U3O8
What to do with DUF6 is a problem of many countries.
aUrenco operates plants in Germany, the Netherlands, and the United Kingdom.
*Source: Management of Depleted Uranium, OECD Nuclear Energy Agency and International Atomic Energy Agency, report number ISBN , 2001.

4. Total DUF6 (metric tons) Location of DUF6 storage sites
DOE Inventory of DUF6
Total DUF6 (metric tons)
Total Cylinders
Location
Paducah, Kentucky
Portsmouth, Ohio
Oak Ridge, Tennessee
Total
36,910
16,041
4,683
57,634
450,000
198,000
56,000
704,000
Location of DUF6 storage sites
This slide gives the sources and locations of DUF6 in the U.S.

5. The U.S. DUF6 Management Program Involves Three Primary Activities
Cylinder storage, surveillance, and maintenance
Conversion of DUF6 to a more stable chemical form for use or disposal
Development of beneficial uses of DU
This slides list the 3 elements of the U.S. DUF6 Management Program

6. 1. Cylinder Storage, Surveillance, and Maintenance
Cylinder Management
57,634 cylinders
704,000 MT of DUF6
The cylinder management program is responsible for safely storing DOE’s DUF6 inventory at Paducah, Portsmouth, and East Tennessee Technology Park sites until the DUF6 is used or disposed of
Inspect cylinders for degradation
Restack cylinders to improve drainage and to allow thorough inspections
Repaint cylinders to arrest corrosion
Build new cylinder yards
Test is self explanatory.
Note how the cylinders are handled. We place cylinders horizontal: I believe the Russians place them verticle.

7. How DUF6 Is Stored
DUF6 is typically stored in carbon steel cylinders that hold 9–12 metric tons of DUF6
The 14-ton-capacity cylinders (12 metric tons) are 12 ft (3.7 m) long by 4 ft (1.2 m) in diameter
Cylinders are initially filled to 95% capacity with liquid DUF6, which is allowed to cool over several days. As the liquid cools, it forms a solid that fills approximately 60% of the internal cylinder volume
Our cylinders ar made of carbon steel.
Each cylinder is about the size of a Volkwagon bettle car, but weights about 14 tons. Remember we have more than 57,000 of these cylinders!

8. DUF6 Storage in the U.S.
Approximately 704,000 metric tons of DUF6 is stored in ~57,600 steel cylinders at three sites in the U.S.
DUF6 is stored horizontally in carbon steel cylinders that hold 9–12 metric tons of DUF6. The cylinders are stored in large outdoor areas called “cylinder yards”
A program of regular surveillance and maintenance activities ensures the safety of continued cylinder storage
Text and picture are self-explanatory.

9. Deteriorating Storage Conditions Cause Environmental and Safety Concerns
The advanced age of some cylinders and the way in which the cylinders were stored have created a potential environmental and safety hazard
Concerns include
Breaches
Rust and corrosion
Yard conditions
Water damage
Ground contact
Text and picture are self-explanatory.
While DUF6 does not present as significant a radiological hazard as other radioactive materials, it is a potential chemical hazard if not properly managed

10. Breach (leak) in a DUF6 cylinder
DUF6 Cylinder Leakage
A small number of cylinders have leaked over the last 40 years; leaking cylinders are repaired, and material that leaks onto the ground is removed
Chemical Reactions During Leakage
If a cylinder leak (breach) occurs and the DUF6 is exposed to water vapor in the air, uranyl fluoride (UO2F2) and hydrogen fluoride (HF) are formed. The uranyl fluoride is a solid that plugs the leak, limiting further escape of DUF6. Release of the hydrogen fluoride gas to the atmosphere is also slowed by the plug formation
Slide is self explanning.
Breach (leak) in a DUF6 cylinder

11. Surveillance and Maintenance Program Activities
The day-to-day management of the DUF6 cylinders includes actions designed to cost-effectively improve their storage conditions
Performing regular inspections and general maintenance of cylinders and storage yards
Restacking and respacing the cylinders to improve drainage and to allow for more thorough inspections
Repainting ends of skirted cylinders and repainting cylinder bodies as needed to arrest corrosion
Constructing new concrete cylinder storage yards and reconditioning existing yards from gravel to concrete to improve storage conditions
Text and pictures are self explanning

12. DU product, aqueous HF, empty cylinders
2. DUF6 Conversion
Full cylinders go to conversion plants at Portsmouth and Paducah
DU product, aqueous HF, empty cylinders
Government-owned and contractor-operated facilities will convert DOE’s DUF6 inventory located at the storage sites to some other stable chemical form acceptable for transportation, beneficial use/reuse, and/or disposal
DUF6 cylinder receipt, inspection, and processing
Cylinder preparation for DUF6 vaporization
Conversion to uranium oxide using Framatome’s dry conversion process
Product storage limited to less than 6 months
Transportation and disposal of uranium oxide
Marketing of HF
This slide is the title slide to Part 2 of the DOE DUF 6 management program
This slide gives the major components of the two DUF6 conversion plants that will be built.
The conversion process that will be used is an existing one used by Framatome ANP. Framatome is one of the partners o f Uranium disposition Services (UDS), LLC, the winners of the RFP to build and operate the conversion plants.
The Russians have proposed “advanced” conversion processes. We are not interested. The conversion n process used is the responsibility of the conversion plant contractor.

13. Conversion of DUF6 to a More Stable Form
DOE has recently awarded a $558M contract to convert and dispose of 704,000 metric tons of DUF6
Contract awarded August 29, 2002, to Uranium Disposition Services, LLC
Framatome ANP
Duratek Federal Services
Burns and Roe
Contract is for
Design, construction, and 5-year operation of two facilities located at the gaseous diffusion plants at Portsmouth, OH, and Paducah, KY
Surveillance and maintenance of cylinder inventory
Shipment of UF6 cylinders from Oak Ridge, TN, to Portsmouth, OH
DU product (DU3O8) sent for disposal, if no reuse is found
Construction to start by July 31, 2004
Contract provides incentives for reuse of DU
The conversion plant contract has been protested by the RFP losers. Thus, few details can be given.
Note that the conversion plant product is an oxide.

14. 3. Development of Beneficial Uses of DU
Depleted Uranium Uses Research and Development Program
Marketable Products
Develop beneficial uses of DUF6 conversion plant products
DU is a potentially valuable energy resource
Goal: Reduce costs by avoiding transportation and disposal costs
Fundamental research
Prototype fabrication and demonstration of near- commercial technology
Focus on DOE system-wide uses and cost reductions
Industry/university cooperation
International collaboration
Reduction of regulatory and institutional barriers
Jon Haire will give a detailed presentation concerning Part 3 of the DUF6 Management Program latter today.
The purpose of the Program is to reduce DOE total system costs. The Program is divided between 1) those uses that consume the DU inventory but have low unit $ value, and 2) fundamental research into innovative new uses that have high intrinsic value but consume only a portion of the inventory.
The DU Uses R&D Project was funded at $1.78 M in FY 2002, with an expected $2.5 M of funding in FY The largest expenditures, by far, are devoted to Program element number 1.

15. Beneficial DU Uses That Consume the Inventory, But Have Low Market Value, $/t DU
Geologic repository
DU surrounding the waste package provides a chemical barrier to spent nuclear fuel (SNF)
SNF and high-level-waste casks
New DU concrete and steel cermet materials enable smaller, lighter-weight casks
Dr. Jonathan Haire will describe, briefly, the use of DU in geologic repositories later today.
Drs. Charles Forsberg and Les Dole will describe the use of DU as a shielding material in spent nuclear fuel casks in their presentations tomorrow.

16. Solar Panel Installed at ORNL Roof Test Facility
Beneficial, Innovative Material Uses That Have High Intrinsic Value, $/t DU
(Royalties from licensing these materials will lower overall DU disposition costs)
Catalysts
Semiconductors
Electrodes for hydrogen production
Batteries
Fuel cells
Others
Dr. Haire will briefly discuss innovate, new DU uses later today.
The “others”bullet on this slide is the reason that we are here today. If you (the Russians) have innovative ideas concerning how DU might be used (e.g. as magnets, as phosphoresce material) we may be interested in collaboration with you on these topics.
Solar Panel Installed at ORNL Roof Test Facility

17. Development of Beneficial Uses of DU
A Depleted Uranium Uses Research and Development Program has been initiated to explore beneficial uses of DU and other materials resulting from conversion of DUF6
DOE is committed to exploring the safe, beneficial use of DU and other materials (e.g., fluorine and empty carbon steel cylinders) resulting from conversion of DUF6 for the purposes of resource conservation and cost savings. Accordingly, a Depleted Uranium Uses Research and Development Program has been initiated. This program explores the risks and benefits of many DU uses
Self explanatory

18. Back-up Slides

19. Where DUF6 Is Stored in the U.S.
The UF6 at the three sites is stored in cylinders in large outdoor areas called "cylinder yards" at the three gaseous diffusion plants where it was produced
DUF6 cylinder yards
DUF6 is stored at the gaseous diffusion plant locations

20. Routine Surveillance and Maintenance Program Activities
A cylinder yard worker vacuums debris from the skirt of a DUF6 storage cylinder
Measuring cylinder wall thickness
The skirted ends of DUF6 cylinders after being painted to arrest corrosion