Effectiveness of the high capacity blowdown for steam generator sludge removal

The steam generator blowdown system is designed to remove the impurities to prevent the steam generator from degradation by the accumulation and buildup of corrosion products. Two-dimensional transient analysis has been performed to simulate the accumulation process of the impurities on the steam generator tubesheet and to investigate the effectiveness of the blowdown on removing the solid particles of various sizes. The solid-water two phase flow has been analyzed with the computational fluid dynamic code, FLUENT. The results show the development of the accumulation and the amount of the sludge on the tubesheet with respect to particle size and blowdown flowrate. The high capacity blowdown is estimated as an effective method for removing the bigger particles. The data from this study will provide useful information for the design and operation of the high capacity blowdown system. (author)