Olkiluoto, the world’s largest and most modern nuclear power station, with an output of 1.600 Mwatts, relies on German technology. During the final assembly of turbine manufacturing at Siemens, blades are installed to the rotor and measured in the housing. This is a balancing act between optimal efficiency and necessary safety margins between blades and housings involving measurements of just tenths of a millimeter.

The steam turbine, which is more than 12 meters long and has a diameter of 6.7 meters, is currently waiting for the final cross section before distribution to the Olkiluoto 3 nuclear power station in Finland. The freestanding blades of the low-pressure turbines are aligned to tenths of a millimeter, despite their mass and weight. “The deciding factor for these blades is their distance to the housing,” says Stefan Hoeyng, plant engineer for final assembly of steam turbines at Siemens AG Power Generation. The gap between turbines and housings must be kept as small as possible, as the larger the distance, the more steam will pass through and this lowers the efficiency. Turbine blades are not allowed under any circumstances to come in to contact with the housing as this causes damage.

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