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Calcium Carbonate Scale Removed from 96234 Titanium Tubes The South Texas STP Nuclear Power Plant in Wadsworth Texas was put into operation in 1988. It was designed with two condenser units acting as heat exchangers to condense the power-generating steam back into a liquid state. It is imperative that the 96234 titanium condenser tubes in each of the two units be maintained in as clean a state as possible to effect optimal condensing efficiency. During a prior maintenance of the two condenser units that each produce 1250 MW of power a scale deposit was found in the tubes of Unit 1 which proved to be a tenacious form of calcium carbonate or calcite. The deposit is a crystalline compound found in such materials as limestone and marble. The thickness of twenty samples tested at STP ranged from 7.6 to 31.2 mils with an average of 19.06 mils. It was also discovered that over 20 of the tubes were blocked completely. The Conco team arrived with a supply of mechanical tube cleaners called Cal-Busters which are specifically designed to break the stratified calcium carbonate deposits. One pass was performed with undersized Conco C4S metal-bladed cleaners followed by multiple passes of various sized Conco Cal-Buster calcium carbonate cutting cleaners that are stepped in size for inside diameters ranging from 15.7 to 17.6 mm 0.620 to 0.694 and a final pass with a C4S to remove the fractured scale. In all 5.7 cubic meters 7.5 cubic yards of calcium carbonate weighing over 2268 kilograms 5000 pounds were removed from the 96234 condenser tubes in Unit 1 and another 3.1 cubic meters 4 cubic yards weighing over 1361 kilograms 3000 pounds were removed from Unit 2. As a result of the condenser tube cleaning and removal of the calcium carbonate scale South Texas Project Nuclear Power Station reports an increase of upwards of 3 MW in power production from the two units a significant improvement. Established 1923 I 3