Simulation of transients with space-dependent feedback by coarse mesh flux expansion method
Creators
- 1. Technische Univ. Muenchen, Garching (F.R. Germany). Lab. fuer Reaktorregelung und Anlagensicherung
Description
For the simulation of the time-dependent behaviour of large LWR-cores, even the most efficient Finite-Difference (FD) methods require a prohibitive amount of computing time in order to achieve results of acceptable accuracy. Static CM-solutions computed with a mesh-size corresponding to the fuel element structure (about 20 cm) are at least as accurate as FD-solutions computed with about 5 cm mesh-size. For 3d-calculations this results in a reduction of storage requirements by a factor 60 and of computing costs by a factor 40, relative to FD-methods. These results have been obtained for pure neutronic calculations, where feedback is not taken into account. In this paper it is demonstrated that the method retains its accuracy also in kinetic calculations, even in the presence of strong space dependent feedback. (orig./RW)
Abstract (German)
Bei der Simulation des zeitabhaengigen Verhaltens grosser LWR-Kerne machen auch die rationellsten Methoden der finiten Differenz (FD-Methoden) einen unverhaeltnismaessig grossen Zeit- und Rechenaufwand erforderlich, um ein einigermassen genaues Ergebnis zu erzielen. Statische Coarse-Mesh-Loesungen mit einer der Brennelementstruktur entsprechenden Gittergroesse (ca. 20 cm) sind mindestens ebenso genau wie FD-Loesungen, die mit einer Gittergroesse von ca. 5 cm berechnet wurden. Bei dreidimensionalen Rechnungen werden dadurch im Vergleich zu FD-Methoden die benoetigte Speicherkapazitaet um einen Faktor 60 und die Rechenkosten um einen Faktor 40 verringert. Diese Ergebnisse gelten fuer einfache Neutronenrechnungen, bei denen Rueckkopplungseffekte ausser Acht gelassen werden. In der Arbeit wird nachgewiesen, dass die Methode auch bei kinetischen Berechnungen und sogar unter den Bedingungen einer starken raumabhaengigen Rueckkopplung nichts von ihrer Genauigkeit einbuesst. (orig./AK)Additional details
Publishing Information
- Imprint Title
- Proceedings of the joint NEACRP/CSNI specialists' meeting on new developments in three-dimensional neutron kinetics and review of kinetics benchmark calculations
- Imprint Pagination
- p. 173-189.
- Report number
- MRR--145
Conference
- Title
- Joint NEACRP/CSNI specialists' meeting on new developments in three-dimensional neutron kinetics and review of kinetics benchmark calculations.
- Dates
- 22 Jan 1975.
- Place
- Garching/Muenchen, F.R. Germany.
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- Germany
- INIS RN
- 7223941
- Subject category
- S22: GENERAL STUDIES OF NUCLEAR REACTORS; S21: SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; S21: SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS;
- Resource subtype / Literary indicator
- Conference, Non-conventional Literature
- Descriptors DEI
- FEEDBACK; FINITE DIFFERENCE METHOD; NEUTRON FLUX; POLYNOMIALS; REACTOR KINETICS; REACTOR KINETICS EQUATIONS; SERIES EXPANSION; SPACE DEPENDENCE; THREE-DIMENSIONAL CALCULATIONS; WATER COOLED REACTORS
- Descriptors DEC
- EQUATIONS; FUNCTIONS; ITERATIVE METHODS; KINETICS; NUMERICAL SOLUTION; RADIATION FLUX; REACTORS
Optional Information
- Notes
- 3 figs.; 3 tabs.; 5 refs. Available from ZAED.
- Secondary number(s)
- AED-Conf--75-328-000.