Advancements in reactor stability analysis methods; personal perspective

Abstract

Understanding the origins and propagation of flow-induced instabilities is very important for the operation and safety of the current and next generations of boiling water reactors (BWR), as well as for future new reactor types, such as the supercritical-pressure reactors, cooled by either water or CO2. Consequently, substantial (or even extensive) efforts have been made during the past 40+ years to investigate the physical phenomena governing such instabilities, and to develop models and computational tools to simulate the dynamics of marginally-stable/unstable boiling systems. The purpose of this paper is to present an updated perspective on, and discuss new aspects of, selected studies performed by the author and his collaborators, associates and graduate students, aimed at the development of various methods for the analysis of flow-induced instabilities in both boiling and supercritical-pressure systems. The impact of model and method selection on the results of predictions will also be discussed for a large class of systems, including the neutronically-coupled oscillations. Since the current paper is a part of the NED issue commemorating 40 years since the first NURETH–series conference, the list of references includes eleven (11) related papers published before in various NURETH proceedings, as well as other related journal articles and conference papers.