The Effect of Header Void Distributions on CANDU Fuel Channel Flow Following Inlet Header Stratification

Abstract

A simple analytical model has been developed which, in conjunction with the heat transport system thermalhydraulic computer code predictions, estimates individual fuel channel coolant flows following inlet header stratification in CANDU reactors. This technique, which was reported previously, is extended in this paper to incorporate the effect of variable vertical void distribution in the reactor header. Existing experiments on void distribution in two-phase piping flow are used to study channel flow sensitivity to void distribution following header flow stratification. It is found that flow in "steam-fed" channels increases significantly for a small amount of water entrainment in the steam.