Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
2013, Volume 16, Issue 1

Pressure Drop Evaluation for a Candu Fuel Bundle at Low Reynolds Number

Abstract

Natural circulation is widely used in nuclear reactors as a means of cooling the core, either in accident conditions or in normal operating mode. However, this three dimensional phenomenon is complex and because of its disadvantages (like low driving forces) there is need for more experiments to be done and validation of codes, in order to prove its reliability. In case of a SBO (Station Black Out) loss of forced circulation, CANDU reactors have the ability to remove heat from the fuel passively, through single-phase or two-phase thermosyphoning and intermittent buoyancy induced flow.

Many aspects have been recently studied about the thermal hydraulic performance of PHWR fuel bundle, but less attention was paid to evaluation of the pressure drops at low Reynolds (Re) number. In this paper the pressure drops in a 37-element simulated CANDU fuel bundle at low Re number, for single-phase regime, were calculated using a CFD (Computational Fluid Dynamics) model. The Re number was varied between 2500 and 24000, and velocities from 0.1 m/s to 1m/s. The obtained results were compared with correlations found in literature.