The low-power low-pressure flow resonance in a natural circulation cooled boiling water reactor Original Research Article

The last few years the possibility of flow resonances during the start-up phase of natural circulation cooled boiling water reactors (BWRs) has been put forward by several authors. The present paper reports on actual oscillations observed at the Dodewaard reactor, the worldʹs only operating BWR cooled by natural circulation. In addition, results of a parameter study performed by means of a simple theoretical model are presented. The influence of relevant parameters on the resonance characteristics, being the decay ratio and the resonance frequency, is investigated and explained.