Stability research on a natural circulation driven SCWR

To improve the thermal efficiency of nuclear reactors, a concept design using supercritical water has been proposed. As an inherent safety feature, natural circulation could be applied, driving the flow with the strong density changes. Such natural circulation flows can however experience instabilities (density wave oscillations). To study the stability, an experimental facility representing the HPLWR was designed using a scaling fluid (R23). In parallel a computational tool was developed which uses a transient analysis technique. This paper will present a comparison of the experimental measurements and numerical predictions for the stability of a supercritical loop, showing good agreement. (author)