TerraPower

Technical Publications

Advancing Research

Employees at TerraPower participate in peer-reviewed scientific research. Members of the team have published papers for numerous journals and conferences. Submissions and conference appearances subject TerraPower’s research to the scrutiny of outside experts.

Most of the papers listed below include links to downloadable copies. For those without links, we have listed summaries and full citations; these may be accessed through most university libraries.

  • A Once-Through Fuel Cycle for Fast Reactors

    Presented at the International Conference on Nuclear Engineering in Brussels in July 2009, this paper discusses the high burn-up rate traveling wave reactors can achieve as well as the implications for materials design.

    ​A shift has occurred in design targets for advanced nuclear energy systems in the fast neutron spectrum. No longer is there a desire to extend fissile fuel reserves; rather, scientists are now seeking to develop “cleaner, more efficient, less waste-intensive and more proliferation-resistant” reactor technologies. A phenomenon known as a traveling wave appears to be one solution to this design challenge. A traveling wave reactor (TWR) is a nuclear reactor designed to enable high fuel burn-up even with minimally enriched fuel, creating an opportunity to employ a fast reactor open fuel cycle. The TWR is fueled almost entirely by depleted or natural uranium, requires little initial enrichment and is designed to use this fuel in place as it operates. Our calculations predict that a TWR could achieve burn-ups of ≥20% and may achieve burn-ups of up to 50%. Contributing factors and design implications are discussed.

    K. WEAVER et al., “A Once-Through Fuel Cycle for Fast Reactors,” Proc. 17th Int. Conf. Nuclear Engineering (ICONE), Brussels, Belgium, July 12-16, 2009, No. 17-75381 (2009).

  • Extending the Nuclear Fuel Cycle with Traveling Wave Reactors

    Members of the research team presented this paper at the Global 2009 conference in September 2009 in Paris, where the theme was “The Nuclear Fuel Cycle: Sustainable Options & Industrial Perspectives.” The paper serves as an introduction to the traveling wave reactor technology and the technical challenges that exist in constructing such a reactor.

    ​Nuclear energy currently supplies about 14% of the world’s electricity needs, and its role is projected to expand even further as nations seek to reduce greenhouse gas emissions and other pollutants generated by the use of fossil fuels. In part, the growth of nuclear energy production depends on what advances can be accomplished in the arenas of economic, safety, waste disposal and proliferation resistance of reactors. Potential has been demonstrated in certain classes of advanced fast-neutron reactors, in particular designs known as traveling wave reactors.

    In September 2002, the Generation IV International Forum selected six next-generation nuclear systems, three of which were fast-neutron reactors whose characteristics and benefits are well understood within the nuclear science and engineering community. These fast reactors use uranium much more efficiently than thermal reactors such as light water reactors (LWRs), and early tests proved they can operate as breeders. Some as-yet-unproven work has explored fast reactor designs that consume minor actinides and some of the long-lived fission products in LWR spent fuel. However, one challenge of these designs is they rely on fuel reprocessing, which can have economic and social ramifications.

    Recent designs and calculations have shown the feasibility of a new variety of fast reactor called a traveling wave reactor (TWR), also known as a breed-and-burn reactor or nuclear-burning-wave reactor. These traveling wave reactors would require no fuel reprocessing, use depleted or natural uranium as their primary fuel, require only a small amount of enriched uranium at start-up and never need refueling. For example, a TWR core with a 60-year operating life would require as little as 7% of the separative work units (SWUs) than a comparable LWR. This core longevity depends on the size of the initial charge of the uranium and on the fuel burn-up achieved during reactor operation.

    Current TWR designs include both low- to medium-power (300-MWe) and large (~1,000-MWe) generation plants with core configuration options that yield burn-ups ranging from 20%-50%. Design specifics and technical challenges are discussed.

    K. WEAVER et al., “Extending the Nuclear Fuel Cycle with Traveling-Wave Reactors,” Proc. Global 2009, Paris, France, September 6-11, 2009, No. 9294 (2009).

  • Direct Use of Depleted Uranium as Fuel in a Traveling-Wave Reactor

    A study of burning depleted uranium in a traveling wave reactor, making use of the neutron excess concept.

    R. PETROSKI, “Direct Use of Depleted Uranium as Fuel in a Traveling-Wave Reactor,” presented at Am. Nucl. Soc. Winter Mtg., Washington, D.C., November 15-19, 2009. Copyright 2009 by the American Nuclear Society, La Grange, Illinois.

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  • Traveling Wave Reactors: A Truly Sustainable and Full-Scale Resource for Global Energy Needs

    Written for presentation at the 2010 International Congress on Advances in Nuclear Power Plants conference in San Diego, this paper explains how traveling wave reactors could help move the global energy economy to a more sustainable footing.

    T. ELLIS et al., “Traveling-Wave Reactors: A Truly Sustainable and Full-Scale Resource for Global Energy Needs,” Proc. Int. Cong. Advances in Nuclear Power Plants (ICAPP), San Diego, California, June 13-17, 2010, No. 10189 (2010).

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  • Conceptual Design of a 500 MWe Traveling Wave Demonstration Reactor Plant

    A summary of the TerraPower conceptual design of a 500 MWe Traveling Wave Reactor.

    C. AHLFELD et. al., “Conceptual Design of a 500 MWe Traveling Wave Demonstration Reactor Plant,” Proc. Int. Cong. Advances in Nuclear Power Plants (ICAPP), Nice, France, May 2-5, 2011, No. 11199 (2011).

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  • A One-Dimensional Benchmark Problem of Breed & Burn Reactor

    A simple benchmark problem is specified for analyzing and calibrating neutronics methods when used to model breed-and-burn nuclear reactors.

    Z. XU et al., “A One-Dimensional Benchmark Problem of Breed & Burn Reactor,” Trans. Am. Nucl. Soc., 105, 786-787 (2011). Copyright 2011 by the American Nuclear Society, La Grange, Illinois.

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  • Technical Considerations and Capabilities of a Near-Term Deployable Traveling Wave Reactor Core

    A partial summary of design limits identified as constraining in practical TWR design.

    N. TOURAN et al., TerraPower, LLC (unpublished).

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  • Issues in Modeling Metallic Fuel Systems with HT9 Clad, invited

    A partial summary of the issues associated with modeling metallic fast reactor fuel from a theoretical and experimental perspective.

    R. LATTA et al., “Issues in Modeling Metallic Fuel Systems with HT9 Clad, invited” Trans. Am. Nucl. Soc., 106, 1207-1208 (2012). Copyright 2012 by the American Nuclear Society, La Grange, Illinois.

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  • Model Biases in High-Burnup Fast Reactor Simulations

    Description of a new multiscale, multiphysics nuclear reactor simulation code system called the Advanced Reactor Modeling Interface (ARMI), developed to provide rapid, user-friendly, high-fidelity full systems analysis.

    N. TOURAN, J. CHEATHAM, and R. PETROSKI, “Model Biases in High-Burnup Fast Reactor Simulations,” Proc. ANS Int. Topl. Mtg. on Advances in Reactor Physics and Linking Research, Industry, and Education (PHYSOR 2012), Knoxville, Tennesee, April 15-20, 2012, American Nuclear Society (2012) (CD-ROM). Copyright 2012 by the American Nuclear Society, La Grange, Illinois.

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  • HT9 Development for the Traveling Wave Reactor, invited

    A partial summary of TerraPower’s efforts to develop the steel alloy HT9 for fuel cladding and duct material.

    M. HACKETT and G. POVIRK. “HT9 Development for the Traveling Wave Reacto,” Trans. Am. Nucl. Soc. 106, 1133-1135, Chicago, IL, June 24-28, 2012. Copyright 2012 by the American Nuclear Society, La Grange, Illinois.

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  • Traveling Wave Reactor Core Design Using Massively Parallel Precomputation

    Description of a new massively parallel precomputation design tool developed to evaluate different Traveling Wave Reactor designs.

    R. PETROSKI, J. CHEATHAM, et.al., "Traveling Wave Reactor Core Design Using Massively Parallel Precomputation," Trans. Am. Nucl. Soc. 106, 830-833, Chicago, IL, June 24-28, 2012. Copyright 2012 by the American Nuclear Society, La Grange, Illinois.

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  • Traveling Wave Reactor Development Program Overview

    Presented at ICAPP 2013, this paper explains how the Traveling Wave Reactor would provide a sustainable energy solution on a global scale for the indefinite future.

    P. HEJZLAR et al., “TerraPower, LLC Traveling Wave Reactor Development Program Overview,” Proc. ICAPP 2013, Jeju Island, Korea, April 14-18, 2013, No. FD226 (2013).

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  • Fast Reactor Design using the Advanced Reactor Modeling Interface

    Presented at the International Conference on Nuclear Engineering in Chengdu in July 2013, this paper addresses the Advanced Reactor Modeling Interface (ARMI) code system that enables efficient and robust fast reactor core design.

    TerraPower developed the ARMI code system for efficient core design. It combines nuclear reactor simulations with system analysis to run independent modules. These modules calculate results, provide external simulation tools and run them, all while update the state of the ARMI system and model. The ARMI system allows “one click” steady-state and assessments throughout the lifetime of a reactor by a single user. This capability increases efficiency by allowing the user to focus on optimizations while a team works on model validation and design improvements.

    J. CHEATHAM et al., “Fast Reactor Design using the Advanced Reactor Modeling Interface,” Proc. 2013 21st Int. Conf. Nuclear Engineering (ICONE), July 29 - August 2, 2013, Chengdu, China, No. 21-16815 (2013).

  • HT9 Strain Modeling for Fuel Pin Deformation

    Members of the research team presented this paper at the International Conference on Nuclear Engineering in Prague in July 2014. The paper addresses the best fuel candidate, HT9 steel, in the TWR fuel cycle.

    TerraPower’s Traveling Wave Reactor is a sodium-cooled fast reactor design consisting of a high-burnup fuel cycle. The fuel system depends on the swelling resistance of the cladding material as well as creep strength. The best candidate for cladding is HT9 steel, for its excellent swelling and strain performance under high stress. A design tool – a strain model – was developed to analyze and anticipate fuel pin deformation because of irradiation stress, temperature and dosage.

    M. HACKETT et al., “HT9 Strain Modeling for Fuel Pin Deformation,” Proc. 2014 22nd Int. Conf. Nuclear Engineering (ICONE), July 7-11, 2014, Prague, Czech Republic, No. 22-30414 (2014).

  • Pin-Level Reconstruction of Various Neutronic Quantities in Fast Reactors: Enhanced Physical Insight

    Written for presentation at the 2013 ANS Annual Meeting in Atlanta, this paper addresses the techniques for reconstruction of various neutronic properties in fast reactors.

    M. REED et al., “Pin-Level Reconstruction of Various Neutronic Quantities in Fast Reactors: Enhanced Physical Insight and Visualization Tools,” presented at Am. Nucl. Soc. Annual Mtg., Atlanta, G.A., June 16-20, 2013. Copyright 2013 by the American Nuclear Society, La Grange, Illinois.

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