NEPTUNE: A New Software Platform for Advanced Nuclear Thermal Hydraulics

Abstract The NEPTUNE project constitutes the thermal-hydraulic part of the long-term Electricité de France and Commissariat à l’Energie Atomique joint research and development program for the next generation of nuclear reactor simulation tools. This program is also financially supported by the Institut de Radioprotection et Sûreté Nucléaire and AREVA NP. The project aims at developing a new software platform for advanced two-phase flow thermal hydraulics covering the whole range of modeling scales and allowing easy multiscale and multidisciplinary calculations. NEPTUNE is a fully integrated project that covers the following fields: software development, research in physical modeling and numerical methods, development of advanced instrumentation techniques, and performance of new experimental programs. The analysis of the industrial needs points out that three main simulation scales are involved. The system scale is dedicated to the overall description of the reactor. The component or subchannel scale allows three-dimensional computations of the main components of the reactors: cores, steam generators, condensers, and heat exchangers. The current generation of system and component codes has reached a very high level of maturity for industrial applications. The third scale, computational fluid dynamics (CFD) in open medium, allows one to go beyond the limits of the component scale for a finer description of the flows. This scale opens promising perspectives for industrial simulations, and the development and validation of the NEPTUNE CFD module have been a priority since the beginning of the project. It is based on advanced physical models (two-fluid or multifield model combined with interfacial area transport and two-phase turbulence) and modern numerical methods (fully unstructured finite volume solvers). For the system and component scales, prototype developments have also started, including new physical models and numerical methods. In addition to scale-specific developments, the generalized use of multiscale calculations is also expected to be a major means to meet the industrial needs. The coexistence of different simulation scales together with the fast growth of computing power multiplies the computation possibilities. In particular, thanks to the recent progress of CFD tools, one can imagine local zooms in some critical parts of the reactor components. The NEPTUNE multiscale platform will offer advanced coupling functionalities based on state-of-the-art software architecture and new numerical coupling techniques. Finally, despite the existence of a huge worldwide database of two-phase flow experiments, the validation of new physical models (more local, more complex) requires new experimental data. That is the reason why for several years we have been developing new instrumentation techniques such as four-sensor optical probes, X-ray tomography, and hot-wire anemometry. These techniques will be used for new experimental programs (currently being launched) that have been defined in connection with the high-priority industrial applications (departure from nucleate boiling, pressurized thermal shock, loss-of-coolant accident, etc.).

[1]  Edwige Godlewski,et al.  The numerical interface coupling of nonlinear hyperbolic systems of conservation laws: II. The case of systems , 2005 .

[2]  D. Bestion,et al.  Progress in improving two-fluid model in system code using turbulence and interfacial area equations , 2005 .

[3]  Jean-Marc Hérard,et al.  Upwind Finite Volume Schemes for One and Two Dimensional Euler Equations , 2003 .

[4]  L. Desbat,et al.  Development and Validation of an X‐ray Tomograph for Two‐Phase Flow , 2002, Annals of the New York Academy of Sciences.

[5]  Wei Yao,et al.  Volumetric interfacial area prediction in upward bubbly two-phase flow , 2004 .

[6]  H. Guillard,et al.  On the behavior of upwind schemes in the low Mach number limit: II. Godunov type schemes , 2004 .

[7]  Philippe Angot,et al.  On the simulation of Nuclear Power Plant Components using a fictitious domain approach , 2005 .

[8]  C. Jayatilleke,et al.  The influence of Prandtl number and surface roughness on the resistance of the laminar sub-layer to momentum and heat transfer , 1966 .

[9]  L. Hochreiter,et al.  Analysis of FLECHT-SEASET 163-rod blocked bundle data using COBRA-TF , 1985 .

[10]  Laurent Desbat,et al.  Development and Validation of an X-Ray Tomograph for Two-Phase Flows , 2002 .

[11]  Benoît Mathieu.  Etudes physique, expérimentale et numérique des mécanismes de base intervenant dans les écoulements diphasiques , 2003 .

[12]  Célia Fouillet.  Généralisation à des mélanges binaires de la méthode du second gradient et application à la simulation numérique directe de l'ébullition nucléée , 2003 .

[13]  Edwige Godlewski,et al.  The numerical interface coupling of nonlinear hyperbolic systems of conservation laws: I. The scalar case , 2004, Numerische Mathematik.

[14]  Joel H. Ferziger,et al.  Computational methods for fluid dynamics , 1996 .

[15]  Heinz Pitsch,et al.  Consistent boundary conditions for integrated LES/RANS simulations: LES outflow conditions , 2002 .

[16]  A. Hasan,et al.  Organisation for Economic Co-operation and Development , 2007 .

[17]  E. Keim,et al.  Life Management of Reactor Pressure Vessels under Pressurized Thermal Shock Loading : Deterministic Procedure and Application to Western and Eastern Type of Reactors , 2001 .

[18]  Jorg Schluter,et al.  Consistent boundary conditions for integrated RANS/LES simulations: Les inflow conditions , 2003 .

[19]  Grégoire Allaire,et al.  A five-equation model for the simulation of interfaces between compressible fluids , 2002 .

[20]  Michel Belliard.  Multigrid preconditioning of steam generator two-phase mixture balance equations in the Genepi software , 2003 .

[21]  Sreenivas Jayanti,et al.  Calculation of dry out and post-dry out heat transfer in rod bundles using a three field model , 2005 .

[22]  Jean-Marc Hérard,et al.  A simple method to compute standard two-fluid models , 2005 .

[23]  M. B. Carver.  Numerical computation of phase separation in two fluid flow , 1984 .

[24]  Philippe Angot,et al.  A penalization method to take into account obstacles in incompressible viscous flows , 1999, Numerische Mathematik.

[25]  M. C. Yuen,et al.  Condensation Measurement of Horizontal Cocurrent Steam/Water Flow , 1984 .

[26]  R. Abgrall,et al.  A Multiphase Godunov Method for Compressible Multifluid and Multiphase Flows , 1999 .

[27]  Samuel Kokh,et al.  A Simple Finite-Volume Method for Compressible Isothermal Two-Phase Flows Simulation , 2006 .

[28]  J. Fabre,et al.  EXPERIMENTAL DATA SET NO. 7: STRATIFIED FLOW, PART I: LOCAL STRUCTURE , 1987 .

[29]  I. Toumi,et al.  FLICA-4: a three-dimensional two-phase flow computer code with advanced numerical methods for nuclear applications , 2000 .

[30]  Stojan Petelin,et al.  Modelling of Two-Phase Flow with Second-Order Accurate Scheme , 1997 .

[31]  Florian Caro,et al.  Modélisation et simulation numérique des transitions de phase liquide-vapeur , 2004 .

[32]  D. Bestion,et al.  The physical closure laws in the CATHARE code , 1990 .

[33]  Grégoire Allaire,et al.  A five-equation model for the numerical simulation of interfaces in two-phase flows , 2000 .

[34]  Michael Z. Podowski,et al.  MULTIDIMENSIONAL EFFECTS IN FORCED CONVECTION SUBCOOLED BOILING , 1990 .

[35]  S. Muzaferija,et al.  Finite-Volume CFD Procedure and Adaptive Error Control Strategy for Grids of Arbitrary Topology , 1997 .

[36]  A. Kumbaro,et al.  An Approximate Linearized Riemann Solver for a Two-Fluid Model , 1996 .

[37]  D. Bestion,et al.  Preliminary Applications of the New NEPTUNE Two-Phase CFD Solver to Pressurized Thermal Shock Investigations , 2004 .

[38]  David H. Sharp,et al.  RENORMALIZATION GROUP SOLUTION OF TWO-PHASE FLOW EQUATIONS FOR RAYLEIGH-TAYLOR MIXING , 1996 .

[39]  Alexandra Junqua-Moullet.  Détermination expérimentale et modélisation de la concentration d'aire interfaciale en écoulement stratifié horizontal , 2003 .

[40]  Richard Saurel,et al.  Mathematical and numerical modeling of two-phase compressible flows with micro-inertia , 2002 .

[41]  Steven F. Son,et al.  Two-phase modeling of DDT: Structure of the velocity-relaxation zone , 1997 .

[42]  E. D. Hughes,et al.  Direct contact condensation and momentum transfer in turbulent separated flows , 1991 .

[43]  S. Bellet,et al.  CFD-Tools Qualification for Thermal-Hydraulics Pressurized Thermal Shock Analysis , 2003 .

[44]  M. Baer,et al.  A two-phase mixture theory for the deflagration-to-detonation transition (ddt) in reactive granular materials , 1986 .

[45]  Eric Hervieu,et al.  Strategy for the Development of a DNB Local Predictive Approach Based on Neptune CFD Software , 2006 .

[46]  Jean-Marc Hérard,et al.  Coupling two and one-dimensional unsteady Euler equations through a thin interface , 2007 .

[47]  Jean-Marc Hérard,et al.  Closure laws for a two-fluid two-pressure model , 2002 .

[48]  D. L. Aumiller,et al.  AN INTEGRATED RELAP5-3D AND MUTLIPHASE CFD CODE SYSTEM UTILIZING A SEMI-implicit coupling technique , 2001 .

[49]  D. Bestion,et al.  Condensation modelling for ECC injection , 1993 .

[50]  J. Greenberg,et al.  Analysis and Approximation of Conservation Laws with Source Terms , 1997 .

[51]  Francesco Saverio D'Auria,et al.  European Project for Future Advance s in Sciences and Technology for Nuclear Engineering Thermal-Hydraulics (EUROFASTNET) , 2001 .

[52]  Sylvie Aubry,et al.  The THYC three-dimensional thermal-hydraulic code for rod bundles : recent developments and validation tests , 1995 .

[53]  Jean-Marc Hérard,et al.  A hyperbolic three-phase flow model , 2006 .

[54]  D. G. Morris,et al.  Dispersed-Flow Film Boiling Heat Transfer Data near Spacer Grids in a Rod Bundle , 1983 .

[55]  T. Gallouët,et al.  Numerical modeling of two-phase flows using the two-fluid two-pressure approach , 2004 .

[56]  Philippe Angot,et al.  Fictitious domain methods to solve convection-diffusion problems with general boundary conditions , 2005 .

[57]  R'bei Bel Fdhila.  Analyse expérimentale et modélisation d'un écoulement vertical à bulles dans un élargissement brusque , 1991 .

[58]  Clifford Goodman,et al.  American Society of Mechanical Engineers , 1988 .

[59]  Aaas News,et al.  Book Reviews , 1893, Buffalo Medical and Surgical Journal.

[60]  Isabelle Ramière,et al.  Méthodes de domaine fictif pour des problèmes elliptiques avec conditions aux limites générales en vue de la simulation numérique d'écoulements diphasiques , 2006 .

[61]  Emmanuel Jouet.  Mise au point et qualification d'une technique de mesure du taux de présence local par tomographie à rayons X , 2001 .

[62]  Jiri Blazek,et al.  Comparison of Two Conservative Coupling Algorithms for Structured-Unstructured Grid Interfaces , 2003 .

[63]  Jean-Michel Ghidaglia,et al.  On the numerical solution to two fluid models via a cell centered finite volume method , 2001 .

[64]  R. Schiestel,et al.  Modélisation et simulation des écoulements turbulents , 1993 .

[65]  Thomas J. Downar,et al.  Development of a comprehensive modeling capability based on rigorous treatment of multi-physics phenomena influencing reactor core design. , 2004 .

[66]  Wei Yao,et al.  Prediction of Parameters Distribution of Upward Boiling Two-Phase Flow With Two-Fluid Models , 2002 .

[67]  Jean-Marc Hérard.  Numerical Modelling of Turbulent Two Phase Flows Using the Two Fluid Approach , 2003 .

[68]  Djamel Lakehal,et al.  Large-eddy simulation of bubbly turbulent shear flows , 2002 .

[69]  Anela Kumbaro.  Flux Scheme: A Method for General Non-Conservative Two-Fluid Systems , 2003 .

[70]  Frank-Peter Weiss,et al.  TOPFLOW : a new multipurpose thermalhydraulic test facility for the investigation of steady state and transient two phase flow phenomena , 2001 .

[71]  Pierre-Antoine Haynes.  Contribution à la modélisation de la turbulence pour les écoulements à bulles : proposition d'un modèle (k-epsilon) multi-échelles diphasique , 2004 .

[72]  Sreenivas Jayanti,et al.  Prediction of dryout and post-dryout heat transfer at high pressures using a one-dimensional three-fluid model , 2004 .

[73]  E. Hervieu,et al.  Benchmarking and improvements of measurement techniques for local-time-averaged two-phase flow parameters , 2003 .

[74]  J. Greenberg,et al.  A well-balanced scheme for the numerical processing of source terms in hyperbolic equations , 1996 .

[75]  M. Ishii,et al.  Thermo-Fluid Dynamics of Two-Phase Flow , 2007 .

[76]  Jean-Marc Hérard,et al.  A sequel to a rough Godunov scheme: application to real gases , 2000 .

[77]  Jean-Marc Delhaye,et al.  FASTNET: A PROPOSAL FOR A TEN-YEAR EFFORT IN THERMAL-HYDRAULIC RESEARCH , 1999 .

[78]  Pascal Laurent-Gengoux,et al.  Fast and Robust Computation of the Matrix Absolute Value Function: Application to Roe Solver for the Numerical Simulation of Two-Phase Flow Models , 2006 .

[79]  P. Roe.  Approximate Riemann Solvers, Parameter Vectors, and Difference Schemes , 1997 .

[80]  Antoine Guelfi,et al.  Multiscale analysis of nuclear reactors thermal-hydraulics - the Neptune project , 2005 .

[81]  Thomas Fortin.  Une méthode d'éléments finis à décomposition L2 d'ordre élevé motivée par la simulation des écoulements diphasiques bas Mach , 2006 .

[82]  Lian Shen,et al.  Turbulent diffusion near a free surface , 2000, Journal of Fluid Mechanics.

[83]  Olivier Hurisse,et al.  A Method To Couple Two-Phase Flow Models , 2006 .

[84]  S. Drobniak,et al.  Coherent structures of free acoustically stimulated jet , 2002 .

[85]  Frédéric Coquel,et al.  A Numerical Method Using Upwind Schemes for the Resolution of Two-Phase Flows , 1997 .

[86]  G. Cubizolles,et al.  LOCAL MEASUREMENTS ON FLOW BOILING OF REFRIGERANT 12 IN A VERTICAL TUBE , 2001 .

[87]  F. Archambeau,et al.  Code Saturne: A Finite Volume Code for the computation of turbulent incompressible flows - Industrial Applications , 2004 .