VOID-INDUCED POWER DISTORTION IN BOILING-WATER REACTORS

The formation of steam bubbles in the core reduces reactivity and causes the power peak to shift away from this region. It is found that steam voids in the core of a large boiling water reactor can cause power-distribution distortions large enough to be of engineering significance. The examples used and the conclusions are applicable to all boiling water reactors that use light water and the dual-cycle principle. (W.D.M.)