This document summarizes goals, scope, and results of an international probabilistic risk assessment (PRA) project for Unit 1 (VVER-1000) of the Kalinin Nuclear Power Station in Russia. The project was organized and managed by U.S. Nuclear Regulatory Commission and the Russian Federal Nuclear and Radiation Safety Authority, Gosatomnadzor, from 1995 to 2004. In 2004 the responsibilities of Gosatomnadzor were subsumed by the newly established Federal Environmental, Industrial and Nuclear Supervision Service of Russia, Rostechnadzor.

The report consists of four sections describing administrative features of the project and technical results of three main areas of the PRA: Level 1 and Level 2 for internal initiators and limited scope studies for other events (fire, flood, and seismic events). The report is directed toward regulatory authority management and specialists familiar with PRA methods.