Seismic isolation is the most effective way to achieve seismic resistance of buildings and structures, the equipment located inside. The energy center of any power plant is its turbine unit - the main equipment responsible for generating electricity. The seismic stability of the turbine unit is ensured primarily by the fulfillment of the seismic resistance criteria by the turbine unit foundation – a special building structure that combines the parts of the turbine unit into a single system and serves to take static and dynamic loads.

Achievement of seismic resistance of the turbine unit foundation of a power plant through the use of various seismic isolation systems is a topical issue discussed in this article.

Dynamic calculations were performed in Nastran software using time history analysis and the finite element method. The main criteria for the seismic resistance of a vibration-insulated turbine foundation are the values of the maximum seismic accelerations in the axial direction at the level of the turbine installation and the values of vibration-insulated foundation maximum seismic deformations of vibration isolators.

In the research, seismic calculations of the turbine unit foundation with various parameters of the double seismic isolation system of the turbine unit were performed. The results made it possible to evaluate the influence of the parameters of the turbine building spring-damper insulation on the seismic resistance of the vibration-insulated turbine unit foundation.

The article is devoted to the determination of the probability characteristics of the parameters that are necessary for the safety analysis of nuclear power plant (NPP) when airplane falls on it. Probability distribution (probability density and cumulative function) of an aircraft trajectory angle with the vertical was found via processing of the world statistics of aircraft accidents. Recurrence of aircraft falls within the bounds of standard area was obtained by means of analysis of aircraft accident protocols with airplanes of general aviation in the United States. These data can be used when designing of NPPs in Russia.

The article is devoted to determination of probability of aircraft fall on nuclear power plant (NPP). Probability distribution of aircraft trajectory angle based on aircraft accidents statistics is used. Equiprobable aircraft approach from any direction is supposed. Probability distribution of impact to a building structure under an arbitrary angle to its normal was determined. Probability of impact to building structures of various shapes (typical for NPPs) was calculated. An example of calculation of the aircraft fall probability on NPP is given. The procedure for determination of the impact probability to building structures at intentional aircraft crash (act of terrorism) was assumed.