www.anl.gov

RECYCLING USED NUCLEAR FUEL FOR A SUSTAINABLE ENERGY FUTURE Pyroprocessing Technologies STORING

Argonne National Laboratory EXPERIMENTAL Building on its USED pioneered the development of BREEDER REACTOR II pyrochemical processing, or Argonne’s pioneering development Historic Past, pyroprocessing, a high-temperature of pyrometallurgical processes led to Argonne is a World method of recycling reactor waste the design and implementation of the into fuel. first-ever recycle process for spent Leader in Developing NUCLEAR metallic reactor fuel from Argonne’s When used in conjunction with Today’s Advanced Experimental Breeder Reactor II nuclear fast reactors, pyroprocessing (EBR-II), a fast reactor. Starting in 1964, Pyroprocessing would: Argonne researchers treated more Technologies FUEL IS A ☐☐ Allow 100 times more of the energy than four metric tonnes of used fuel in uranium ore to be used to with the pyroprocess to recover and produce electricity compared recycle uranium and plutonium to to current commercial reactors. EBR-II. This successful fuel treatment REAL WASTE. ☐☐ Ensure almost inexhaustible effort led to continued research supplies of low-cost uranium and development of pyrochemical resources. processes for the recycle of oxide, carbideand other advanced fuels and ☐☐ Minimize the risk that used fuel laid the foundation for Argonne’s would be used for weapons work today. Nuclear power is the most production by recycling the uranium and transuranics to fast reactors for INTEGRAL FAST environmentally friendly way energy production. REACTOR PROGRAM ☐☐ Markedly reduce both the amount Argonne’s development of the of generating large amounts of of waste and the time it must be Integral Fast Reactor (IFR), a isolated—from approximately groundbreaking liquid metal- electricity on demand. Through 300,000 to approximately 300 cooled fast reactor designed for years—by recycling all actinides. energy production and waste consumption, ushered in the use of Today, Argonne National Laboratory the development and application another pyroprocess for recycling researchers are developing and used fuel. Researchers found refining several pyroprocessing of advanced technologies for that an electrochemical process technologies for both light water and separated the desired actinides from fast reactors, working to improve the the fission products for recycling recycling “spent,” or used nuclear technologies’ commercial viability by into new fuel and addressed the increasing their process efficiency problems associated with increasing fuel, nuclear power could also and scalability. requirements for disposal of become truly sustainable and high-level waste. essentially inexhaustible.

B 1 CHEMICAL AND FUEL CYCLE TECHNOLOGIES ARGONNE NATIONAL LABORATORY

Through pyroprocessing THE BASICS OF WHAT IS FISSION? PYROPROCESSING and the much more efficient (AND OTHER DEFINITIONS) fast reactor fuel cycle, vastly Fission The splitting of the nuclei of more of the energy in the heavy-metal atoms (mainly uranium and other actinides) The electrorefining procedure is key to pyrochemical uranium ore can be used to resulting in the release of large recycling of used nuclear fuel. This process removes produce electricity. amounts of energy. the waste fission products from the uranium and other Fission products actinides (heavy radioactive elements) in the used The true waste of fission, a fuel. The unfissioned uranium and actinides are then mixture of lighter elements recycled to fast reactors. created when the heavy atom splits. Turning Nuclear Waste into a “Wonderfuel” Used fuel Argonne’s pyrochemical process research is opening the doors to a sustainable ELECTROREFINING RESEARCH Unfissioned uranium and other nuclear energy future for the nation. The laboratory’s goals are to:  Optimize energy production and use of resources actinides (including plutonium and   several other heavy radioactive  Provide advanced pyroprocessing technologies that are economical to use  elements). The actinides are the  Argonne scientists and engineers are developing commercially viable technologies Fission products to be recovered in a subsequent process and encapsulated in durable waste forms main source of today’s nuclear withOXIDE the following characteristics: Most of the include: fission products waste problem.  Robust process chemistry and engineering Uranium and  High product quality  Increasing throughput (i.e., batch size) to enable the treatment of used light water reactor fuel  Uranium, other other actinides  Scalability  actinides and salt Actinides  Minimal secondary waste production  Metal Oxide In line fuel with from U.S. thermal non-prolife reactorsration objectives to the design of commercial systems Heavy radioactive elements, including neptunium, plutonium, americium, and curium, that are METAL Metal separated out during recycling, and remain with the unfissioned Salts uranium as they are recycled back into new fuel. The actinides Chopped metallic fuel are then destroyed in fission, Argonnefrom’s comprehensive fast reactors vision for an expanded, sustainable nuclear energy system turning them into short-lived fission products.

USED FUEL OXIDE REDUCTION UNIT ELECTROREFINER CATHODE PROCESSOR FUEL FABRICATION FURNACE If the reprocessing and refueling steps are repeated enough times, Used fuel from today’s light water, The oxide fuel is first converted to Electrorefining is very similar to These extracted elements are then Finally, the remaining actinides and nearly all the actinides will have or thermal,6 reactors—uranium oxide metal through oxide reduction. electroplating. Used fuel attached7 sent to the cathode processor where uranium are cast into fresh fuel rods been fissioned, leaving only with a small amount of plutonium and to an anode is suspended in a the residual salt from the refining and the salt is recycled back into the short-lived waste fission products other actinide oxides—is converted chemical bath; electric current then process is removed and recycled electrorefiner. containing very little actinides. to a metal through oxide reduction. dissolves the used fuel and plates back to the electrorefiner. This process not only reduces the While used metallic fuel—uranium, out the uranium and other actinides amount of waste created, but also plutonium, and other actinides— on the cathode. the time it must be isolated—from from fast reactors goes straight to approximately 300,000 years to the refiner. approximately 300 years.

2 3 CHEMICAL AND FUEL CYCLE TECHNOLOGIES ARGONNE NATIONAL LABORATORY

ELECTROREFINING TURNING RESEARCH

ABOUT ELECTROREFINING NUCLEAR WASTE Electrorefining is the key to pyrochemical processing: an electrometallurgical treatment of spent nuclear fuel that uses molten salt to recover the uranium and other actinides for recycling into new fuel. INTO A Electrorefining enables: ☐☐ Fission product and actinide partitioning ☐☐ Electrodeposition of actinides for recycle “WONDERFUEL” ☐☐ Fission products to be recovered in a subsequent process and encapsulated in durable waste forms Argonne’s pyrochemical process research is opening the doors to a sustainable nuclear energy future for the nation. CURRENT R&D AT ARGONNE Argonne’s current electrorefining R&D focuses on The Laboratory’s goals are to: Argonne scientists and engineers are developing process efficiency and scalability. Research activities include: ☐☐ Optimize energy production and use of resources commercially viable technologies with the following characteristics: ☐☐ Increasing throughput (i.e., batch size) to enable the ☐☐ Manage the fission waste in an environmentally ☐☐ treatment of used light water reactor fuel responsible manner Robust process chemistry and engineering ☐☐ ☐☐ High product quality Incorporating automated product recovery to enhance ☐☐ Provide advanced pyroprocessing technologies that and increase throughput are economical to use ☐☐ Scalability ☐☐ Developing intermittent actinide removal from cathodes ☐☐ Minimal secondary waste production to enhance process efficiency ☐☐ In line with U.S. non-proliferation objectives ☐☐ Conceiving and evaluating prototype test electrorefining module designs to establish data essential to the design of commercial systems A VISION FOR A SUSTAINABLE NUCLEAR ENERGY SYSTEM

Uranium product collected during advanced refiner testing.

Argonne’s comprehensive vision for an expanded, sustainable nuclear energy system

4 5 CHEMICAL AND FUEL CYCLE TECHNOLOGIES ARGONNE NATIONAL LABORATORY

ELECTROREDUCTION TECHNOLOGY

Argonne researchers also pioneered an electrolytic reduction process that has become the standard head-end treatment for converting oxide fuel to base metals for subsequent treatment by electrorefining. This approach enables the treatment of used light water reactor and fast reactor oxide fuel. The viability of the electroreduction process chemistry was demonstrated in laboratory-scale and high-capacity Recovering samples from pyroprocessing testing for analysis. Scientists review data from in situ process monitoring for Conceptual pyroprocessing facility testing many years ago. Argonne researchers designed a pyrochemical systems. flexible engineering test-bed for equipment engineering and integration with other unit operations. This includes: ADVANCED ELECTROCHEMICAL IN SITU PROCESS MONITORING FOR PYROCHEMICAL PROCESSING FACILITY CONCEPT ACTINIDE CO-DEPOSITION PYROCHEMICAL SYSTEMS To further advance Argonne’s pyroprocessing work ☐☐ Modular components with integrated heat shielding Argonne researchers recently patented an innovative A powerful process monitoring and safeguards technology and the potential for recycling used nuclear fuel, ☐☐ Multiple cathode slots to test staggered reduction technology for depositing both the uranium and for the electrorefining systems used in actinide recovery researchers developed a conceptual 100 metric tonne process operation transuranic (other actinides such as neptunium, plutonium, is being developed by Argonne’s research team, which per year pyroprocessing facility. This work includes the and americium) metal product onto a solid cathode includes experts in process research and nuclear development of processes, equipment concepts, an ☐☐ An anode and anode shroud that have the flexibility during electrorefining for recycling into fast reactor fuel. safeguards. Reliable process monitoring and control operations model, and the identification of materials to evaluate alternative materials, geometries, and During their work, a more detailed understanding of the technologies are essential for operating a commercial fuel handling issues. immersion depths fundamental electrochemistry behind co-deposition is treatment facility. ☐☐ A flexible cathode design to evaluate variable being gained. The technology: A variety of electroanalytical methods including cyclic and bed thicknesses, interelectrode spacing, and ☐☐ Features robust process chemistry that limits the square-wave voltammetry, and spectroscopic techniques immersion depths impurities being carried over into the fuel. Fewer are being developed and evaluated to determine the ☐☐ Multiple fuel baskets compatible with the planar impurities in the fuel could increase fuel burn-up in the quantity of actinide in molten salt. This research includes electrorefiner prototype module reactor, resulting in fewer recycle steps developing: ☐☐ Reduces the complexity of the process when compared ☐☐ Methods that achieve representative and reproducible to older technologies conditions at the sensing electrode/molten salt solution ☐☐ Maintains the non-proliferation features critical to U.S. interface fuel cycles ☐☐ Methods to determine the sensing electrode’s effective area, which is vital to accurate concentration measurements

6 7 KEY ARGONNE BREAKTHROUGHS IN PYROPROCESSING

URANIUM ELECTROREFINING Eliminated the need for adding chemicals during the fuel treatment process. Instead, uranium and other actinides are separated from the fission products by electrochemical methods. This approach eliminates the need for extensive solvent recycle and simplifies the design of process facilities.

PURIFIED URANIUM METAL The first deposit of purified uranium metal greater than a kilogram in weight was produced during the early electrorefiner development.

MARK IV ELECTROREFINER The first pilot-scale uranium electrorefiner successfully recovered uranium from the spent driver fuel of Experimental Breeder Reactor-II (EBR-II).

MARK V ELECTROREFINER The first high-throughput system (see image at right) successfully demonstrated the treatment of EBR-II used fuel. Without recycling, most of the energy that could be extracted ADVANCED PROTOTYPE ELECTROREFINER The highly scalable design is essential for treating used from the original uranium ore fuel from light water reactors because of its substantial— will be “tossed away,” and stored almost 95 percent—uranium content. as waste. ELECTROCHEMICAL REDUCTION OF OXIDE FUEL Argonne’s groundbreaking pyroprocessing Enables the closure of the nuclear fuel cycle by recovering technologies enables 100 times more of the uranium and other actinides from used light water reactor energy in uranium ore to be used, and by fuel for use in fast reactor fuel. recycling all actinides it significantly reduces the amount of nuclear waste and the time it ACTINIDE CO-DEPOSITION must be isolated. Enables recovery of uranium and other actinides from the refiner; this limits the impurities being carried over into the fuel and meets U.S. non-proliferation objectives.

See the video on Argonne’s pyroprocessing research: http://youtu.be/MlMDDhQ9-pE

8 9 www.anl.gov

ARGONNE NATIONAL LABORATORY ☐☐ U.S. Department of Energy research facility ☐☐ Operated by the University of Chicago ☐☐ Midwest’s largest federally funded R&D facility ☐☐ Located in Lemont, IL, about 25 miles (40 km) southwest of Chicago, IL (USA) ☐☐ Conducts basic and applied research in dozens of fields ☐☐ Unique suite of leading-edge and rare scientific user facilities

CONTACT Mark Williamson Chemical and Fuel Cycle Technologies Phone: 630-252-9627 E-mail: [email protected] anl.gov/cfc