Optimized Core Design of a Supercritical Carbon Dioxide-Cooled Fast Reactor

Abstract The gas-cooled fast reactor (GFR) has received increased attention in the past decade under the impetus provided by the Generation-IV International Forum. The GFR given principal attention is a version using helium as a coolant. However, the work presented here is for a core using supercritical carbon dioxide (S-CO2) as a coolant, in a direct Brayton cycle, which has comparable cycle efficiency (~45%) at much lower temperatures (e.g., 650°C versus 850°C) than helium-based cycles. A reactor core for use in this direct cycle S-CO2 GFR has been designed that satisfies established neutronic and thermal-hydraulic steady-state design criteria, while concurrently supporting the Gen-IV criteria of sustainability, safety, proliferation, and economics. Use of innovative tube-in-duct fuel has been central to accomplishing this objective, as it provides a higher fuel volume fraction and lower fuel temperatures and pressure drop when compared to traditional pin-type fuel. Further, this large fuel volume fraction allows for a large enough heavy metal loading for a sustainable core lifetime without the need for external blankets, enhancing the proliferation resistance of such an approach. It was not possible to achieve a sustainable core (i.e., conversion ratio = 1.0) using conventional pin-type oxide fuel. Use of beryllium oxide (BeO) as a diluent is explored as a means for both power shaping and coolant void reactivity (CVR) reduction, similar to the studies carried out earlier for the sodium-cooled European Fast Reactor. Results show that relatively flat power profiles can be maintained throughout a batch-loaded “battery” core life of more than 15 yr using a combination of fissile concentration and diluent zoning, due to the moderating effect of the BeO. Combining BeO diluent with the innovative strategy of using a thick volume of S-CO2 coolant in the radial reflector yields negative CVR values throughout core life, a rare, if not unique accomplishment for fast reactors. The ability to maintain negative CVR comes from a combination of the effects of spectral softening due to the BeO diluent and the enhanced leakage upon voiding of the S-CO2 radial reflector.

[1]  Vaclav Dostal,et al.  A Supercritical CO{sub 2} Cycle- a Promising Power Conversion System for Generation IV Reactors , 2006 .

[2]  R. Moore,et al.  Behaviour of BeO under neutron irradiation , 1964 .

[3]  M. J. Driscoll,et al.  ASSESSMENT OF GAS COOLED FAST REACTOR WITH INDIRECT SUPERCRITICAL CO 2 CYCLE , 2006 .

[4]  K. H. Sarma,et al.  New processing methods to produce silicon carbide and beryllium oxide inert matrix and enhanced thermal conductivity oxide fuels , 2006 .

[5]  C. Degueldre,et al.  Thermal conductivity of zirconia based inert matrix fuel: use and abuse of the formal models for testing new experimental data , 2003 .

[6]  E. Ruckenstein,et al.  The characterization of a highly effective NiO/MgO solid solution catalyst in the CO2 reforming of CH4 , 1997 .

[7]  D. Wade,et al.  The Integral Fast Reactor Concept: Physics of Operation and Safety , 1988 .

[8]  Dennis Ross Poulter Nuclear Engineering. (Book Reviews: The Design of Gas-Cooled Graphite-Moderated Reactors) , 1963 .

[9]  J. Collier,et al.  Gas-cooled Fast Reactor , 1968, Nature.

[10]  C. E. Till,et al.  Integral Fast Reactor concept , 1986 .

[11]  F. Illas,et al.  Ab Initio Cluster Model Calculations on the Chemisorption of CO2 and SO2 Probe Molecules on MgO and CaO (100) Surfaces. A Theoretical Measure of Oxide Basicity , 1994 .

[12]  C. P. Gratton The GCFR revisited , 2003 .

[13]  H. P. Planchon,et al.  Implications of the EBR-II inherent safety demonstration test☆ , 1987 .

[14]  Timothy Abram,et al.  A Technology Roadmap for Generation-IV Nuclear Energy Systems, USDOE/GIF-002-00 , 2002 .

[15]  Zhiwen Xu,et al.  Design strategies for optimizing high burnup fuel in pressurized water reactors , 2003 .

[16]  R. Campana,et al.  Irradiation testing of design models for the GCFR fuel pressure equalization (vent) system , 1974 .

[17]  R. Konings,et al.  On the thermal conductivity of inert-matrix fuels containing americium oxide , 1998 .

[18]  M. Driscoll,et al.  The Linear Reactivity Model for Nuclear Fuel Management , 1991 .

[19]  Nathan Carstens Speedup of MCNP(X) parallel KCODE execution via communication algorithm development and Beowulf Cluster optimization , 2004 .

[20]  B. S. Hickman,et al.  The effect of neutron irradiation on beryllium oxide , 1964 .

[21]  Neil E. Todreas,et al.  Conceptual Design of a Large, Passive Pressure-Tube Light Water Reactor , 1994 .

[22]  Vaclav Dostal,et al.  High-Performance Supercritical Carbon Dioxide Cycle for Next-Generation Nuclear Reactors , 2006 .

[23]  K. Kawashima,et al.  Utilization of fast reactor excess neutrons for burning long lived fission products , 1995 .

[24]  P. Medvedev,et al.  Development of dual phase magnesia-zirconia ceramics for light water reactor inert matrix fuel , 2005 .

[25]  Claude Degueldre,et al.  Thermophysical Properties of Inert Matrix Fuels for Actinide Transmutation. , 2003 .

[26]  M. J. Driscoll,et al.  Optimized, Competitive Supercritical-CO2 Cycle GFR for Gen IV Service , 2008 .

[27]  Neil E. Todreas,et al.  Fertile-Free Fast Lead-Cooled Incinerators for Efficient Actinide Burning , 2004 .

[28]  N. Todreas,et al.  Hydrodynamic models and correlations for bare and wire-wrapped hexagonal rod bundles — Bundle friction factors, subchannel friction factors and mixing parameters , 1986 .

[29]  M. Driscoll,et al.  An advanced vented fuel assembly design for GFR applications , 2005 .

[30]  Mujid S. Kazimi,et al.  High Performance Fuel Design for Next Generation PWRs: Final Report , 2006 .

[31]  George E. Apostolakis,et al.  Risk-informed design guidance for future reactor systems , 2005 .