Risk and safety analyses of reactor WWER-1000 normal operation systems

A systematic approach is presented in this report for determining the capability of normal, safety-critical, operating systems to reliably implement required safety functions. The approach consists of a reliability evaluation of the systems and of their affect on the availability of specified safety functions. In accordance with this systematic approach, the activities presented in the report include definition of the: system safety functions that can be implemented by the systems based on their functional use; conditions under which the system is capable of implementing the specified safety functions; and reliability function for the specified safety functions aimed at determining the effectiveness of the systems. These parameters are obtained using fault tree analysis.