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

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.

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 92-64-19525-4, 2001.

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.

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

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.

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!

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.

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

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

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

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.

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.

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 2003. The largest expenditures, by far, are devoted to Program element number 1.

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.

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

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

Back-up Slides

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

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