Characteristics of marine biofouling and automatic cleaning system for all titanium tube condenser

For the condenser tubes of nuclear power plants, the higher reliability is demanded, therefore, titanium tubes have become to be practically used. Titanium tubes are excellent in the corrosion resistance in seawater, therefore, the seawater leak due to corrosion damage and the deterioration of heat transfer characteristics due to the formation of corrosion products can be eliminated. On the other hand, titanium tubes are apt to suffer from the fouling due to marine organisms, accordingly, in order to obtain the stable performance and high reliability of the condensers for nuclear power plants, the counter-measures to the fouling by organisms peculiar to sea areas must be sufficiently established. Chubu Electric Power Co., Inc. and Hitachi Ltd. installed a model condenser with all titanium tubes in Hamaoka Nuclear Power Station, which can well simulate the state of operation of an actual machine. The fouling characteristics of titanium tubes in each season, the frequency of cleaning and the optimum method using sponge balls, the development of an automatic counter for sponge balls, the systematizing of automatic cleaning, the fouling by organisms of tube plates and so on are reported. (Kako, I.)