Depleted Uranium Hexafluoride DUF 6 Storage Conversion and

Depleted Uranium Hexafluoride (DUF 6 ) 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 December 9– 10, 2002 Moscow, Russia OAK RIDGE OPERATIONS 1

Depleted Uranium (DU) Is a Legacy of Uranium Enrichment OAK RIDGE OPERATIONS 2

Worldwide DU Inventory* Inventory (MTU) Storage form United States 480, 000 UF 6 France (COGEMA and Eurodif) 190, 000 U 3 O 8 Urencoa 16, 000 UF 6 United Kingdom (BNFL) 30, 000 UF 6 Russia 460, 000 UF 6 Japan 10, 000 UF 6 2, 000 UF 6 Enricher Republic of Korea China a. Urenco 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 92 -64 -19525 -4, 2001. OAK RIDGE OPERATIONS 3

DOE Inventory of DUF 6 Location of DUF 6 storage sites Total Cylinders Total DUF 6 (metric tons) Paducah, Kentucky 36, 910 450, 000 Portsmouth, Ohio 16, 041 198, 000 4, 683 56, 000 57, 634 704, 000 Oak Ridge, Tennessee Total OAK RIDGE OPERATIONS 4

The U. S. DUF 6 Management Program Involves Three Primary Activities 1. Cylinder storage, surveillance, and maintenance 2. Conversion of DUF 6 to a more stable chemical form for use or disposal 3. Development of beneficial uses of DU OAK RIDGE OPERATIONS 5

1. Cylinder Storage, Surveillance, and Maintenance Cylinder Management The cylinder management program is responsible for safely storing DOE’s DUF 6 inventory at Paducah, Portsmouth, and East Tennessee Technology Park sites until the DUF 6 is used or disposed of 57, 634 cylinders 704, 000 MT of DUF 6 • Inspect cylinders for degradation • Restack cylinders to improve drainage and to allow thorough inspections • Repaint cylinders to arrest corrosion • Build new cylinder yards OAK RIDGE OPERATIONS 6

How DUF 6 Is Stored • DUF 6 is typically stored in carbon steel cylinders that hold 9– 12 metric tons of DUF 6 • 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 DUF 6, 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 OAK RIDGE OPERATIONS 7

DUF 6 Storage in the U. S. Approximately 704, 000 metric tons of DUF 6 is stored in ~57, 600 steel cylinders at three sites in the U. S. DUF 6 is stored horizontally in carbon steel cylinders that hold 9– 12 metric tons of DUF 6. 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 OAK RIDGE OPERATIONS 8

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 While DUF 6 does not present as significant a radiological hazard as other radioactive materials, it is a potential chemical hazard if not properly managed OAK RIDGE OPERATIONS 9

DUF 6 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 DUF 6 is exposed to water vapor in the air, uranyl fluoride (UO 2 F 2) and hydrogen fluoride (HF) are formed. The uranyl fluoride is a solid that plugs the leak, limiting further escape of DUF 6. Release of the hydrogen fluoride gas to the atmosphere is also slowed by the plug formation Breach (leak) in a DUF 6 cylinder OAK RIDGE OPERATIONS 10

Surveillance and Maintenance Program Activities The day-to-day management of the DUF 6 cylinders includes actions designed to costeffectively 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 OAK RIDGE OPERATIONS 11

2. DUF 6 Conversion Full cylinders go to conversion plants at Portsmouth and Paducah Government-owned and contractoroperated facilities will convert DOE’s DUF 6 inventory located at the storage sites to some other stable chemical form acceptable for transportation, beneficial use/reuse, and/or disposal DU product, aqueous HF, empty cylinders · DUF 6 cylinder receipt, inspection, and processing · Cylinder preparation for DUF 6 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 OAK RIDGE OPERATIONS 12

Conversion of DUF 6 to a More Stable Form DOE has recently awarded a $558 M contract to convert and dispose of 704, 000 metric tons of DUF 6 • 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 UF 6 cylinders from Oak Ridge, TN, to Portsmouth, OH • DU product (DU 3 O 8) sent for disposal, if no reuse is found • Construction to start by July 31, 2004 • Contract provides incentives for reuse of DU OAK RIDGE OPERATIONS 13

3. Development of Beneficial Uses of DU Depleted Uranium Uses Research and Development Program Develop beneficial uses of DUF 6 conversion plant products DU is a potentially valuable energy resource Goal: Reduce costs by avoiding transportation and disposal costs Marketable Products · Fundamental research · Prototype fabrication and demonstration of nearcommercial technology · Focus on DOE system-wide uses and cost reductions · Industry/university cooperation · International collaboration · Reduction of regulatory and institutional barriers OAK RIDGE OPERATIONS 14

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 OAK RIDGE OPERATIONS 15

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 Solar Panel Installed at ORNL Roof Test Facility OAK RIDGE OPERATIONS 16

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 DUF 6 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 DUF 6 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 OAK RIDGE OPERATIONS 17

Back-up Slides OAK RIDGE OPERATIONS 18

Where DUF 6 Is Stored in the U. S. The UF 6 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 DUF 6 is stored at the gaseous diffusion plant locations DUF 6 cylinder yards OAK RIDGE OPERATIONS 19

Routine Surveillance and Maintenance Program Activities A cylinder yard worker vacuums debris from the skirt of a DUF 6 storage cylinder The skirted ends of DUF 6 cylinders after being painted to arrest corrosion Measuring cylinder wall thickness OAK RIDGE OPERATIONS 20