Study of a low Mach nuclear core model for two-phase flows with phase transition I: stiffened gas law

¹ IFPEN – Lyon, BP 3, 69360 Solaize, France.
manuel.bernard@ifpen.fr
² DEN/DANS/DM2S/STMF, Commissariat à l’Énergie Atomique et aux Énergies Alternatives – Saclay, 91191 Gif-sur-Yvette, France.
stephane.dellacherie@cea.fr
³ Université de Toulon – IMATH, EA 2134, avenue de l’Université, 83957 La Garde, France.
faccanon@univ-tln.fr
⁴ MAP5 UMR CNRS 8145 – Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints Pères, 75270 Paris Cedex 6, France.
berenice.grec@parisdescartes.fr
⁵ CEREMA-INRIA – team ANGE and LJLL UMR CNRS 7598, 4 place Jussieu, 75005 Paris, France.
yohan.penel@cerema.fr

Received: 11 November 2012
Revised: 11 February 2014

Abstract

In this paper, we are interested in modelling the flow of the coolant (water) in a nuclear reactor core. To this end, we use a monodimensional low Mach number model supplemented with the stiffened gas law. We take into account potential phase transitions by a single equation of state which describes both pure and mixture phases. In some particular cases, we give analytical steady and/or unsteady solutions which provide qualitative information about the flow. In the second part of the paper, we introduce two variants of a numerical scheme based on the method of characteristics to simulate this model. We study and verify numerically the properties of these schemes. We finally present numerical simulations of a loss of flow accident (LOFA) induced by a coolant pump trip event.