DETERMINATION OF BUBBLE-SIZE DISTRIBUTION IN A BWR.

Abstract A procedure for determining the bubble-size distribution in an operating natural circulation BWR utilizing a digital type void meter and a bubble speed meter is described in detail. The relationship between void signal and bubble size is established, subject to justifiable assumptions, in the form of an integral equation. With this equation, the average bubble diameter and the average bubble volume can be derived from the normalized histogram with respect to penetration lengths of the bubbles. The bubble-size distributions found in the riser and in the downcomer have solved some of the steam separation problems in the plenum, where the recirculation flow changes from upwards to downwards.