Siemens Power Generation (PG) is to supply the world’s largest steam turbine-generator for the Finnish nuclear power plant Olkiluoto 3. It comprises one high-pressure and three low-pressure turbines, and a generator. "The technology featured in this steam turbine-generator is designed for maximized performance, highest efficiency, highest availability and a long service life," said Dr. Uriel Sharef, member of the Siemens Corporate Executive Committee, during the Corner Stone ceremony in Olkiluoto, Finland, on September 12.
The gigantic piece of equipment, almost 70 meters long and weighing more than 5,000 tons (equivalent to the weight of 3,300 intermediate-class cars), will be built at the Siemens PG manufacturing plant in Muelheim, Germany. The turbine-generator will have a capacity of approximately 1,600 megawatts, which is enough to reliably supply a city with 1.6 million inhabitants and its industry. The shaft of the turbine-generator will rotate at a speed of 1500 revolutions per minute, and the final-stage blades in the low-pressure turbines are almost two-meter-long. These blades have deadweight of 340 kg. The company has already supplied similar turbine-generators to several nuclear power plants around the world.
Almost 2,500 kg of steam at a pressure of 78 bar and a temperature of 293 degrees Celsius flows through the high-pressure turbine cylinder every second. The blades in the four turbine cylinders feature three-dimensional optimization. This ensures that the energy contained in the steam is optimally utilized. The type of blading developed by Siemens PG, with the designation 3DV, already has a proven service record in numerous steam turbines.
The company not only builds steam turbines for nuclear and fossil-fueled power plants. As part of servicing and modernization projects in nuclear power plants, Siemens PG has to date upgraded more than 36 plants with a combined capacity of over 45,000 megawatts in nine countries to the latest state of the art. The company has orders in hand for a further 17 plants with combined capacity of over 19,000 megawatts. In 2004, for example, the existing low-pressure turbines at the Forsmark 3 nuclear power plant in Sweden, which had incurred stress corrosion cracking, were replaced with the Siemens advanced disk design with its proven track record. This measure eliminated the problems in the old machines supplied by a third-party vendor and also uprated the unit by more than 30 megawatts. The investment is thus amortized within a few years not only through the reduced maintenance costs but also through the power uprating.
The contract for turnkey construction of the Olkiluoto 3 nuclear power plant was awarded to the Framatome ANP/Siemens consortium in late 2003 by the Finnish utility Teollisuuden Voima Oy (TVO). Two nuclear power plant units are already in operation at this site. The startup of Olkiluoto 3 is scheduled for 2009.