[en] Both 1300 MW units of Nuclear power plant Iran 1 and 2 will be built in a zone of high seismic risk near Bushehr at the Persian Golf. The turbine building does not belong to the class 1 buildings (safety-related parts), but the customer wanted a dimensioning against operating basis earthquake (OBE). Due to these high seismic forces, an alteration of structure was necessary and therefore KWU's standard construction couldn't be adopted. A dynamic modal analysis using the response spectrum method for ground acceleration of 0.1 g was carried out and the resulting maximum base shear forces were compared with SEAOC-code. Structural elements with high reinforcement ratios were economically designed using 50 mm diameter bars with threaded rips (GEWI-Steel d sub(e) = 50mm). (Author)