Coolant Flow Instabilities in Power Equipment.

Abstract

It is customary to regard flow instability as a periodic or single change of thermal-hydraulic parameters in channels or circulating loops when a plant operates under steady-state conditions. Thermal-hydraulic instability may impair thermal reliability of reactor core or other power equipment components. It has been shown in numerous publications that a sudden decrease in flow rate can lead to superheating and burnout in a heated channel. Also, periodic oscillations may cause failure of the channel wall or fuel element cladding because of the periodic magnetite layer deterioration. Flow rate or pressure fluctuations may lead to low-frequency vibrations