Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 32009
Nonlinear Thermal Hydraulic Model to Analyze Parallel Channel Density Wave Instabilities in Natural Circulation Boiling Water Reactor with Asymmetric Power Distribution

Authors: Sachin Kumar, Vivek Tiwari, Goutam Dutta


The paper investigates parallel channel instabilities of natural circulation boiling water reactor. A thermal-hydraulic model is developed to simulate two-phase flow behavior in the natural circulation boiling water reactor (NCBWR) with the incorporation of ex-core components and recirculation loop such as steam separator, down-comer, lower-horizontal section and upper-horizontal section and then, numerical analysis is carried out for parallel channel instabilities of the reactor undergoing both in-phase and out-of-phase modes of oscillations. To analyze the relative effect on stability of the reactor due to inclusion of various ex-core components and recirculation loop, marginal stable point is obtained at a particular inlet enthalpy of the reactor core without the inclusion of ex-core components and recirculation loop and then with the inclusion of the same. Numerical simulations are also conducted to determine the relative dominance between two modes of oscillations i.e. in-phase and out-of-phase. Simulations are also carried out when the channels are subjected to asymmetric power distribution keeping the inlet enthalpy same.

Keywords: Asymmetric power distribution, Density wave oscillations, In-phase and out-of-phase modes of instabilities, Natural circulation boiling water reactor

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1971


[1] O. J. A. Boure, A. .E. Bergles and L. S. Tong, Review of Two-Phase Flow Instability, Nuclear Engineering and Design 25 (1973) 165-192..
[2] J. M. Leuba and J. M. Rey, Coupled Thermohydraulic-Neutronic Instabilities in Boiling Water Nuclear Reactors: A Review of the State of the Art, Nuclear Engineering and Design 145 (1993) 97-111..
[3] F. D'Auria (Project Coordinator), Neutronics/Thermal-hydraulics Coupling in LWR Technology, Tech. rep., Vol. 2, CRISSUE-S WP2: Stateof-the-Art Report, OECD/NEAN. 5436 (2004).
[4] G. V. D. Prasad, M. Pandey and M. S. Kalra, Review of Research on Flow Instabilities in Natural Circulation Boiling Systems, Progress in Nuclear Energy 49 (2007) 429-451.
[5] A. K. Nayak and P. K. Vijayan, Flow Instabilities in Boiling Two-phase Natural Circulation Systems: A Review, Science and Technology of Nuclear Installations (Article ID 573192, 15 pages, doi:10.1155/2008/573192).
[6] W. Ambrosini, P. D. Marco and J. C. Ferreri, Linear and Nonlinear Analysis of Density Wave Instability Phenomena, Publicado en International Journal of Heat and Technology 18 (1) (2000) 27-36.
[7] Rizwan-uddin, On Density-Wave Oscillations in Two-Phase Flows, Int. J. Multiphase Flow 20 (4) (1994) 721-737. Rizwan-uddin and J. J. Dorning, A Chaotic Attractor in a Periodically Forced Two-Phase Flow System, Nuclear Science and Engineering 100 (1988) 393-404.
[8] Rizwan-uddin and J. J. Dorning, Chatic Dynamics of a Triply-Forced Two-Phase Flow System, Nuclear Science and Engineering 105 (1990) 123-135.
[9] A. Clausse and Jr. R. T. Lahey, The Analysis of Periodic and Strange Attractors during Density-Wave Oscillations in Boiling Flows, Chaos, Solitons and Fructals 1(2) (1991) 167-178.
[10] R. O. S. Prasad, J. B. Doshi and K. Iyer, A Numerical Investigation of Nuclear Coupled Density Wave Oscillations, Nuclear Engineering and Design 154 (1995) 381-396.
[11] S. Narayanan, B. Srinivas, S. Pushpavanan and S. M. Bhallamudi, Nonlinear Dynamics of a Two Phase Flow System in an Evaporator: The Effects of (i) a Time Varying Pressure Drop, (ii) an Axially Varying Heat Flux, Nuclear Engineering and Design 178 (1997) 279-294.
[12] G. Dutta, J. B. Doshi, A Characteristics-Based Implicit Finite-Difference Scheme for the Analysis of Instability in Water Cooled Reactors, Nuclear Engineering and Technology 40 (6) (2008) 477-488.
[13] D. Hennig, A Study of Boiling Water Reactor Stability Behavior, Nuclear Technology 126 (1999) 10-31.
[14] H. Ikeda, T. Ama, K. Hashimoto and T. Takeda, Nonlinear Behavior under Regional Neutron Flux Oscillations in BWR Cores, Journal of Nuclear Science and Technology 38 (5) (2001) 312-323.
[15] H. I. F. F. Y. K. H. Soneda, S. Mizokami, BWR Stability Issues in Japan, Science and Technology of Nuclear Installations (Article ID 358616, 11 pages, doi: 10.1155/2008/358616).
[16] G. Dutta and J. B. Doshi, Nonlinear Analysis of Nuclear Coupled Density Wave Instability in Time Domain for Boiling Water Reactor Core undergoing Core-wide and Regional Modes of Oscillations, Progress in Nuclear Energy 51 (2009) 769-787.
[17] Y. N. Lin, J. D. Lee and C. Pan, Nonlinear Dymanics of Nuclear-Coupled Boiling Channel with Forced Flows, Nuclear Engineering and Design 179 (1998) 31-49.
[18] J. M. Leuba and E. D. Blakeman, A Mechanism for Out-of-phase Power Instabilities in Boiling Water Reactors, Nuclear Science and Engineering 107 (1991) 173-179.
[19] M. Aritomi, S. Aoki and A. Inoue, Thermo-hydraulic Instabilities in Parallel Boiling Channel Systems Part 1. A Non-linear and a Linear Analytical Model, Nuclear Engineering and Design 95 (1986) 105-116.
[20] J. L. Munoz-Cobo, R. B. Perez, D. Ginestar, A. Escriva and G. Verdu, Non Linear Analysis of Out of Phase Oscillations in Boiling Water Reactors, Annals of Nuclear Energy 23, No. 16 (1996) 1301-1335.
[21] J. L. Munoz-Cobo, M. Z. Podowski and S. Chiva, Parallel Channel Instabilities in Boiling Water Reactor Systems: Boundary Conditions for Out of Phase Oscillations, Annals of Nuclear Energy 29 (2002) 1891- 1917.
[22] J. D. Lee and C. Pan, Dymanics of Multiple Parallel Boiling Channel Systems with Forced Flows, Nuclear Engineering and Design 192 (1999) 31-44.
[23] W. T. Hancox and S. Banerjee, Numerical Standards for Flow-Boiling Analysis, Nuclear Science and Engineering 64 (1977) 106-123.
[24] S. Banerjee and W. T. Hancox, On the Development of Methods for Analysing Transient Flow-Boiling, Int. J. Multiphase Flow 4 (1978) 37-460.
[25] G. Dutta and J. B. Doshi, A Numerical Algorithm for the Solution of Simultaneous Nonlinear Equations to Simulate Instability in Nuclear Reactor and its Analysis, in: 11th International Conference on Computational Science and its Applications, Vol. 6783 of Lecture Notes in Computer Science, Springer, University of Cantabria, Santander, Spain, 2011, pp. 695-710.
[26] J. L. Munoz-Cobo, O. Rosello, R. Miro, A. Escriva, D. Ginestar and G. Verdu, Coupling of Density Wave Oscillations in Parallel Channels with High Order Modal Kinetics: Application to BWR Out of Phase Oscillations, Annals of Nuclear Energy 27 (2000) 1345-1371