Development of a 3-D Finite Element Model to Examine Fuel Bundle Behaviour under Post-Dryout Heat Transfer Conditions

Abstract

Elements in a CANDU fuel bundle can deform (i.e., deflect or bow) during their residence in the fuel channel by thermally-induced phenomena. Although small deflections are warranted, there is a risk that under post-dryout conditions, the induced thermal gradient may increase this effect and put the integrity of the fuel and fuel channel at risk. With reactor aging effects potentially affecting sub-channel thermalhydraulics, the chance of dryout occurring is increased. The purpose of this work is to develop a 3-D finite element model to examine element deformation when subjected to the thermal conditions in post-dryout heat transfer.