Simulation of loss-of-flow transients in research reactors

The course of loss-of-flow transients in pool-type research reactors, with scram disabled, is investigated. The analysis is performed with a customize d version of the code PARET. The focus is on determining the two-phase flow stability boundaries as Function of initial reactor conditions, recognizin g that flow instability is the basic mechanism responsible for core damage in such type of transients. A. useful chart is provided, which describes th e stability region in terms of initial reactor power, initial pool temperat ure, peaking factor, and flow-decay time constant. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.