Tectonic Conditions of Ignalina NPP Region

Region of the Ignalina nuclear power plant (INPP) is situated in the zone of junction of two large regional structures of Mazurian-Belarussian anteclyse and Latvian saddle. There are two types of tectonic faults: pre-platformic and platformic. Most distinctive fault series are those of Drukshiai depression (graben), Anisimovichi graben and Skirnas graben. Fault amplitudes are not large, usually less than 10-25 m. Only the amplitudes of Drukshiai and Anisimovichi graben faults reach 55-60 m. As most active ones, the faults of Drukshiai (near to INPP area), Anisimovichi, Skirnas etc. grabens are to be mentioned. Latitudinal zone active geotectonically crosses the INPP area as well. Fault activity is confirmed by measurements of vertical Earth crust movements in the geodynamical polygon established around Lake Drukshiai. It is necessary to build a system for antiseismic security for automatic stopover of the reactors and for registration of earthquakes in the INPP region. Designing additional power engineering units they should meet the requirements applied for seismic regions, i.e. they should be seismoresistant. 8 refs., 11 figs