To account the transition state of the system during probabilistic calculations reservation own needs of NPP

Abstract

In this paper, the method is proposed for preliminary probabilistic safety analysis of the own needs reservation systems for nuclear power plants, which takes into account temporal changes of equipment failure rate since the beginning of the accident and to restore functionality. The method allows to take into account Russian and foreign statistics of the intensities of the initial emergency events, including power failure by reason of extreme natural conditions (for example, the Middle Volga region Russia during the 100 years). The presented method also allows conducting the preliminary assessment of the annual risk level reduction of the damage caused by accidents with core damage (ACD) NPP reactors in money equivalent based on statistics of economic damage caused by such accidents that took place at nuclear power plants. As an example, according to the proposed method, the multifunction system reservation own needs NPP was investigated, based on a combination stations with an additional low-power steam turbine installation. According to calculations, accounting time-dependent processes by this method allows to specify for the given initial data the final results of the calculation for intensities of the reactor ACD and the risk level reduction of the annual emergence of damage caused by accidents ACD reactors by more than 1,3 times.

Keywords

• nuclear power plants
• reservation of own needs
• reactor core damage
• steam-turbine plant
• probabilistic safety analysis of non-stationary processes
• intensity of failures