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Short Course: Thermal-Hydraulics of Nuclear Systems

the CUNY Energy Institute and University of Wisconsin Energy Institute PROUDLY HOST SHORT COURSE IN THERMAL-HYRDRAULICS OF NUCLEAR SYSTEMS


The Marriott Residence Inn, Bethesda

Washington, DC

October 24-28, 2011



Single and multiphase flows and heat transfer with phase change are of interest to researchers and engineers working in all aspects of the nuclear industry. The course offered here is related to similar courses that have been offered in the past at Stanford University, the University of California-Santa Barbara and the ETH-Zurich but with greater emphasis on the thermal-hydraulic aspects of nuclear systems. The area continues to be of interest to generations of engineers with the ETH course having been offered continuously since 1984 with over 1500 participants. The course being offered in Washington DC continues this tradition and affords not only the opportunity to meet outstanding lecturers, but also colleagues working nationwide on similar topics.

The course is organized in a modular form with an intensive introductory part for participants having basic knowledge of fluid mechanics, heat transfer, and numerical techniques, but also with a second more specialized part that discusses the latest information and applications. A tutorial text is e-mailed to the participants before the course to introduce the very basic concepts to fill any gaps in background and help participation in the courses in the most productive ways.

Part I: Bases covers the common background material and emphasizes the latest modeling and computational aspects of single and multiphase flows in nuclear systems

Part II: Applications covers single and multiphase flow topics specifically of topical interest to nuclear systems. This part reviews, for example, recent developments with applications to design basis accidents, spent fuel cooling, steam generator tube rupture analyses, coupled neutronics-thermal-hydraulics, degraded core effects on long term cooling as well as beyond design basis accidents.

Part III: Computational Multiphase Fluid Dynamics (CMFD) presents the latest commercial and applications-oriented computer models as applied to nuclear systems.


The emphasis in these courses is on:

  • A condensed, critical and updated view of basic knowledge and future developments in relation to systems and phenomena encountered in nuclear industry applications
  • Trends in modeling, design, analysis, computational techniques, CFD / CMFD methods and experimentation
  • Sources of information, data and correlations
  • Availability as well as limitations of modern modeling and computational techniques and codes
  • Interdisciplinary transfer of knowledge from other areas of application to nuclear systems

This limited-enrollment course features:

  • A program of coordinated lectures by experts in the field in fundamentals and applications
  • A complete and extensive set of lecture notes in electronic form plus handout-format copies of all the standardized PowerPoint presentations
  • Videos, animations, and computer simulations illustrating the physical phenomena and numerical techniques
  • Discussion time and discussions with the lecturers during and between lectures





To register for the thermal-hydraulics short course, please fill out the following form and send an email to





Parts I, II & III taken together: $2400

Part I ONLY: $1500



Make your check payable to "The City College Fund."  Mail to Ms. Elena Sturman by September 10, 2011.

Ms. Elena Sturman, Executive Director
The City College Fund Shepard Hall # 166
160 Convent Avenue New York, NY 10031

If credit card payment is required, please contact Ms. Elena Sturman directly.
Phone: 212-650-6529


The fees include the cost of course materials but do NOT include meals and hotel accommodations. An administrative fee of $100 will be retained in case of cancellation after September 23, 2011.







MONDAY, October 24 (9-12:30 and 14-17:30)

1. Introduction: M. L. Corradini. Nuclear system descriptions, current and advanced designs. Significant flow phenomena with examples. Operational and safety implications. Current thermal-hydraulics issues. Layout of lectures, where topics addressed.

2. Introduction to Nuclear Fluid Mechanics and Heat Transfer: S. Banerjee. Fundamentals of fluid mechanics and heat transfer as applied to nuclear systems. Conservation equations and constitutive models. Ensemble, volume and cross-sectional area averaging. Simple closure relationships for friction, drag and heat transfer. Single-phase flow applications, steady-state and transients; single-phase anticipated operational transients. Multiphase flows, definitions and phenomena; examples in nuclear systems. Introduction to flow regimes (movie).

3. Engineering Models for Two-Phase Flow: G. Yadigaroglu . Engineering approaches to two-phase flow predictions in nuclear systems. Flow regime correlations. Correlations for frictional pressure gradient and void fraction. Countercurrent flow limitations and correlations. Applications.

4. Phenomenological Models for Multiphase Flow: G.F. Hewitt. Vertical flows: Phenomenological models for bubble flow, bubble/slug transition. Slug flow and the slug churn transition. Churn flow. Churn/annular transition. Annular flow. Wispy annular flow. Phenomenological models for horizontal flows: Stratified flow. Stratified/slug transition. Slug flow. Stratified/slug/annular transition. Annular flow. Applications to nuclear Systems.

TUESDAY, October 25 (9-12:30 and 14-17:30)

5. Light Water Reactor Phenomena: G. Yadigaroglu. Normal operation thermalhydraulics, anticipated operational occurrences, loss-of-coolant accidents, and their simulation; uncertainty evaluation. In-vessel accident phenomenology; modelling of core cooling. Passive emergency core and containment cooling.

6. Two-phase heat transfer: G.F. Hewitt. Single component systems; heat transfer regimes, heat transfer in slug flow (equilibrium, non-equilibrium); heat transfer in annular flow, correlations, mechanisms, models (overall, detailed, effect of nucleate boiling). Dryout (critical) heat flux; low quality (bubbly) and high quality (annular) flows. Condensation; similarities and differences to evaporation. Non-condensible effects.

7. Dryout in simple and complex geometries: G. F. Hewitt. Dryout in tubular and annular geometries. Core configurations in conventional and advanced PWR's and BWR's. Critical heat flux in rod bundle geometries; prediction methods (global models, sub-channel methods, phenomenological models); effects of non-uniform flux distribution; grid design for enhancement.

8. Advanced Light Water Reactor Concepts and Phenomena: M. L. Corradini. Review of advanced LWR concepts for near-term and Generation IV reactor development. Two-phase phenomena in passive safety systems (natural circulation, condensation, critical flow).

WEDNESDAY, October 26 11 (9-12:30 and 14-17:30)

9. Thermal non-equilibrium flows: G. Yadigaroglu. Importance of departures from mechanical and thermal equilibrium in nuclear systems. Computation of non-equilibrium flows. Subcooled boiling. Post-dryout heat transfer; 3D effects.

10. Multifield models: S. Banerjee. The need for multifield models. Interpenetrating continua and Lagrangian- Eulerian approaches. Closure requirements. One-dimensional form – structure, strengths and weaknesses. Multidimensional aspects – applicability and limitations.

11. Numerical methods: S. Banerjee. Introduction to finite differences. Initial and boundary conditions. Method of characteristics. Finite difference methods. Stability. Explicit and implicit methods used in computer codes.

12. Closure laws in nuclear systems codes: S. Bajorek. Development and validation of closure laws dependent on flow regime. Hydrodynamic and heat transfer closure relationships in system codes and their limitations. Predicting choked flow, stratified flow, CCFL.


THURSDAY, October 27 (9-12:30 and 14-17:30)

13. Two-Phase Instabilities: G.Yadigaroglu. Instabilities of the liquid-gas interface; applications to jets, particles, etc. Two-phase system instabilities; fundamentals, mechanisms. Computational tools, stability maps. BWR stability.

14. Nuclear Systems Codes: S.Bajorek. Modeling of nuclear systems at the component level, modeling approach and nodalization approach. Review of major system code models, such as TRACE, COBRA/ TRAC, VIPER, TRACE, TRACG and perhaps RAMONA and NOTRUMP.

15. Single Phase Models and Subchannel Analysis: S.Bilbao. Subchannel analysis modelling approach, transverse momentum transport, grid spacer and wire-wrap effects, multi-channel flow analyses and core-wide analysis approaches.

16. CFD for Nuclear Systems: C.Boyd. Overview of available tools for CFD. Solvers, models and algorithms. A selection of examples illustrating some of the challenges and advanced models used in the analyses of nuclear single- and multi-phase flow problems.

17. CFD for Fuel Storage Systems: G.Zigh. Overview of fuel storage systems and thermal-hydraulic challenges to model long-term cooling. A selection of examples illustrating water cooling and air cooling of spent fuel will be discussed.

FRIDAY, October 28 (8:30-12:30)

18. Coupled Neutronics and Thermal-Hydraulics: T.Downar. The basic couplings (diffusion eqs and the effects of void fraction and Doppler). Normal and accident situations where the coupling becomes important: ATWS, boron mixing, stability of BWRs, extended operating domain operations.

19. Long Term Cooling: S.Banerjee. Overview of recirculation cooling modes, debris effects. GSI 191 and current status. Debris generation and transport, sump screen blockage, chemical and thin bed effects, downstream effects for PWRs Implications for BWRs. Degraded core cooling, fluidized bed effects.

20. LWR Beyond Design Basis Safety Analyses: M.L.Corradini. Multiphase phenomena during severe accidents: vapor explosions, molten core quenching and coolability, etc. Severe accident modeling with system analyses and simulation.

PART III. CMFD with Commercial Codes (Tentative Schedule)

FRIDAY, October 28 (13:30-17:30)

21. Simulation of multiphase flow in nuclear systems: CASL Computational Simulation Tools.

22. Modelling and Commercial CFD simulation: STAR-CCM and FLUENT.

23. Simulating multiphase flows in accidents: MELCOR and MAAP.



Sanjoy Banerjee is Distinguished Professor of Chemical Engineering and Director of the Energy Institute at the City University of New York and publishes extensively on nuclear thermalhydraulics. Previously he was Professor of Chem. Engng. at the Univ. of Calif. – Santa Barbara. Member of the US NRC Advisory Committee on Reactor Safeguards, ACRS. Earlier in Canada, he occupied the positions of Westinghouse Professor of Engineering Physics at McMaster Univ. and of Acting Director of Applied Science in the Whiteshell Nuclear Research Establishment. He was a founding member of the Canadian Advisory Committee on Nuclear Safety. He has received ASME Melville Medal, IChemE (UK) Danckwerts Lecturership, AIChE Kern Award, ASME Heat Transfer Memorial Award and ANS Technical Achievement Award in Thermal-hydraulics. Fellow of ANS.

Michael L. Corradini is Chair and Wisconsin Distinguished Professor of Nuclear Engng at the Univ. of Wisconsin-Madison. He is also a member of the US NRC Advisory Committee on Reactor Safeguards (ACRS), member of NRC safety review panels and of the DoE Generation IV Roadmap Project. He has published widely in areas related to vapour explosion and severe accident phenomena, jet spray dynamics and transport phenomena in multiphase systems. Member of the National Academy of Engineering and Fellow of ANS.

Geoffrey F. Hewitt is Professor Emeritus of Chemical Engineering at Imperial College, London. Founder of the Heat Transfer and Fluid Flow Service (HTFS) at the Harwell Laboratory. He has authored and edited many books and published over 500 papers and reports. Former Editor of Multiphase Science and Technology and Former Executive Editor of the Heat Exchanger Design Handbook. Recipient of the AIChE Donald Q. Kern, the ASME Max Jacob awards, the Nusselt Reynolds Prize, the Luikov Medal, the IChemE Council and Armstrong medals, the Senior Multiphase Flow Award and the Global Energy Prize. He has Hon. Doctorates from Louvain, UMIST and Heriot Watt. Fellow of the Royal Academy of Engng, Fellow of the Royal Society, and Foreign Associate of the US Natl Academy of Engng.

George Yadigaroglu is Professor Emeritus of Nuclear Engng, ETH-Zurich and President and cofounder of ASCOMP, an ETH spin-off company specializing in CMFD simulations. Was also Head of the Thermal-Hydraulics Laboratory at the Paul Scherrer Institute. Previously Professor of Nucl. Engng at the Univ. of California-Berkeley. Active in research and consulting and a member of several international high-level committees dealing with nuclear safety issues. ANS Technical Achievement Award. ANS and ASME Fellow. Former Assoc. Editor of the Int. J. of Multiphase Flow.

Stephen M. Bajorek is the NRC Senior Technical Advisor for Thermal-Hydraulics approximately ten years, where he is involved in development of the TRACE code, advanced reactor analysis, and the NRC's thermal-hydraulic test programs. Prior to joining the staff he was a member of the faculty at Kansas State University in the Department of Mechanical and Nuclear Engineering. He has 15 years of industrial experience at Westinghouse Electric Corp., where he was involved with the AP600 Design Certification, thermal-hydraulic code development and licensing of the Westinghouse Best Estimate LOCA methodology. Dr. Bajorek received his Ph. D. from Michigan State University, and M.S. and B.S. degrees in Mechanical Engineering from the University of Notre Dame.

Sama Bilbao y León is currently an Associate Professor and the Director of Nuclear Engineering Programs at Virginia Commonwealth University. While at Dominion Generation, she led the development and licensing of new methodologies in core thermal-hydraulics and nuclear safety analysis in support of Dominion's nuclear power stations. As Technical Head of the International Atomic Energy Agency Water Cooled Reactors Technology Development Unit, she was in charge of all IAEA activities in support of the development and near term deployment of advanced water-cooled reactors and their associated fuels.

Christopher Boyd is a senior level advisor for computational fluid dynamics (CFD) within the Office of Nuclear Regulatory Research at the Nuclear Regulatory Commission (NRC). He carried out the program to bring CFD tools "in-house" for the NRC during the 1990s and has spent the past 15 years utilizing these tools for nuclear safety analyses. Previously, he spent 9 years working on instrumentation development and optimization for high-speed wind tunnel testing at the Naval Surface Warfare Center. He received his Ph.D. in Mechanical Engineering at the University of Maryland in the area of thermal-fluids behavior.

Thomas Downar received his PhD from MIT in 1984 and from 1984-2006 was a Professor in the School of Nuclear Engineering at Purdue University. After a year as a Professor at UC Berkeley, he joined the faculty at the University of Michigan where he is currently a Professor and Graduate Chair in the Nuclear Engineering and Radiological Sciences Department. Professor Downar is a Fellow of the American Nuclear Society. The primary focus of his research is nuclear reactor physics and multiphysics computational methods in support of the U.S. NRC, the U.S. DOE, EPRI and several international agencies. He is the author of the U.S. NRC core neutronics simulator PARCS and has contributed to the development of the thermal-hydraulics codes TRACE and RELAP5. The coupled neutronics and thermal-hydraulics codes TRACE/PARCS and RELAP5/PARCS are used worldwide to perform the safety analysis of most every type of power reactor currently operating in the world.

Ghani Zigh is a Senior Technical Advisor in the US NRC in the Office of Research, and is a registered PE (Professional Engineer) in the state of New York. He has been a USNRC staff member since August 2002, and involved in dry cask applications, BWR and PWR Zircaloy Fire (accident analysis), APWR advanced accumulators, fire analysis, and ultrasonic flow meters. Prior to the NRC, he worked at Parsons Brinkerhoff (PB) in Manhattan as an international consultant using CFD (Computational Fluid Dynamics) to model fire and emergency ventilation for tunnels and train stations as well as the effects of thermal pollution of power plants on ocean and rivers. He was also an adjunct professor at Stevens Institute of Technology in New Jersey where he taught undergraduate and graduate classes in Mechanical Engineering.






Address additional correspondence to:


Prof. Sanjoy Banerjee
CUNY Energy Institute
Steinman Hall, The City College of New York
140 Convent Avenue
New York, NY 10023
Phone: 212-650-8149

Prof. Michael Corradini
Energy Institute
University of Wisconsin
1500 Engineering Dr.
Madison WI 53706
Phone: 608-263-1648


More information about the course and hotel reservations CAN BE found at the course web site: Please SEND EMAIL INQUIRIES TO