Multigroup neutron reflection and leakage conditions for axial core models with anisotropic scattering
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M. P. de Abreu
Abstract
In this article, multigroup discrete ordinates interface conditions for neutron reflection and leakage were derived for axial models of nuclear reactors with anisotropic scattering. These conditions are completely free from spatial truncation error. The key to the derivation is a suitable reformulation of exact discretized equations – the multigroup spectral nodal equations – defined in the nonactive boundary regions at top and bottom. The resulting interface conditions can be used to replace the nonactive boundary regions of a nuclear reactor core in axial reactor computations. In order to illustrate the improvements that can be experienced by most one-dimensional multigroup discrete ordinates codes with our multigroup interface conditions, we perform a numerical experiment with a representative multigroup code and an axial core model with anisotropic scattering.
Kurzfassung
In diesem Artikel werden Multigruppen-diskrete-Ordinaten-Übergangsbedingungen für die Neutronenreflektion und -verlust bei axialsymmetrischen Reaktorkernmodellen mit anisotroper Streuung entwickelt. Diese Bedingungen sind fehlerfrei bezüglich räumlicher Abschneidebedingungen. Der Schlüssel zu dieser Ableitung ist eine geeignete Neuformulierung von genau diskriminierten Gleichungen – spektrale, nodale Multigruppen-Gleichungen, die in den nicht aktiven Randbereichen oben und unten definiert werden. Die resultierenden Übergangsbedingungen können dazu verwendet werden, die nicht aktiven Randbereiche eines Reaktorkerns in eindimensionalen Reaktorberechnungen zu ersetzen. Zur Darstellung der Verbesserung, die bei den meisten eindimensionalen Multigruppen-diskrete-Ordinaten Berechnungen durch unsere Multigruppen-Übergangsbedingungen erhalten werden kann, wurde eine numerische Simulation mit einem repräsentativen Multigruppen-Algorithmus und einem axialen Kernmodell mit anisotroper Streuung durchgeführt.
References
1Alcouffe, R. E.; O'Dell, R. D., Transport calculations for nuclear reactors. In: CRC Handbook of Nuclear Reactors Calculations, Ed. Y.Ronen, Vol. I, CRC Press Inc., FL (1986)Suche in Google Scholar
2Alves Filho, H.; de Barros, R. C.: Use of SN albedo boundary conditions for one non-multiplying region considering indented reflector around the core. Proceedings of the 18th International Conference on Transport Theory, Rio de Janeiro, Brazil, 240 (2003)Suche in Google Scholar
3Badruzzaman, A.: Nodal methods in transport theory. In: Advances in Nuclear Science and Technology, Eds. J.Lewins and M.Becker, Vol. 21, Plenum Press, New York (1988)Suche in Google Scholar
4de Abreu, M. P.; Alves Filho, H.; de Barros, R. C.: A numerical method for multigroup slab-geometry eigenvalue problems in transport theory with no spatial truncation error. Transport Theory & Statistical Physics25 (1996) 61Suche in Google Scholar
5de Abreu, M. P.: Numerical methods for the generation of the spectrum of the multigroup slab-geometry discrete ordinates operator in neutron transport theory. Annals of Nuclear Energy29 (2002) 1837Suche in Google Scholar
6de Abreu, M. P.: Mixed singular-regular boundary conditions in multislab radiation transport. Journal of Computational Physics197 (2004) 167Suche in Google Scholar
7de Abreu, M. P.: Neutron reflection and leakage models for one-dimensional reactor computations. Kerntechnik70 (2005) 133Suche in Google Scholar
8de Abreu, M. P.: Multi-layer models to neutron reflection and transmission for whole-core transport calculations. Annals of Nuclear Energy32 (2005) 215Suche in Google Scholar
9Dias, A. F.; Garcia, R. D. M.: Coupled scalar and vector PN methods for solving multigroup transport problems in multislab geometry. Annals of Nuclear Energy27 (2000) 160710.1016/S0306-4549(00)00046-3Suche in Google Scholar
10Duderstadt, J. J.; Hamilton, L. J.: Nuclear Reactor Analysis. John Wiley & Sons, New York (1976)Suche in Google Scholar
11Lewis, E. E.; MillerJr., W. F.: Computational Methods of Neutron Transport. American Nuclear Society, La Grange Park, IL (1993)Suche in Google Scholar
12RSICC-ORNL software packages and their applications [www-rsicc.ornl.gov/rsiccnew/RSICC_catalog.pdf].Suche in Google Scholar
© 2006, Carl Hanser Verlag, München
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Current use of probabilistic safety evaluations for advanced reactor concepts
- Experiments and comparing calculations on thermohydraulic pressure surges in pipes
- Experimental investigation and CFD simulation of horizontal air/water slug flow
- Uncertainty and sensitivity analysis of the CPS-CC voiding in the RBMK reactor Ignalina-2
- Irradiation damages in tantalum spallation target
- Multigroup neutron reflection and leakage conditions for axial core models with anisotropic scattering
- Performance analyses of the pool-top radiation level reduction systems at the ETRR-2 research reactor
- An interpretation procedure for the purpose of incorporation monitoring during decommissioning of nuclear reactors
- Thermal hydraulics of the fixed bed nuclear reactor concept
- Technical Note
- The critical slab problem for linearly anisotropic scattering and reflecting boundary conditions with the HN method
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Current use of probabilistic safety evaluations for advanced reactor concepts
- Experiments and comparing calculations on thermohydraulic pressure surges in pipes
- Experimental investigation and CFD simulation of horizontal air/water slug flow
- Uncertainty and sensitivity analysis of the CPS-CC voiding in the RBMK reactor Ignalina-2
- Irradiation damages in tantalum spallation target
- Multigroup neutron reflection and leakage conditions for axial core models with anisotropic scattering
- Performance analyses of the pool-top radiation level reduction systems at the ETRR-2 research reactor
- An interpretation procedure for the purpose of incorporation monitoring during decommissioning of nuclear reactors
- Thermal hydraulics of the fixed bed nuclear reactor concept
- Technical Note
- The critical slab problem for linearly anisotropic scattering and reflecting boundary conditions with the HN method
