Practical application of the ''compact model'' for I and C modeling in the european pressurizer reactor (EPR) probabilistic safety assessment (PSA)

The EPR is an advanced Pressurized Water Reactor (PWR) under development within FRAMATOME ANP and SIEMENS NPG, and with the support of their clients: a group of major German Utilities and the French Utility (EDF). Designers have expressed their willingness to engage probabilistic studies in the design process so as to assess the safety level in order to support and to optimize the choice of design options. This practice permits to reach well-balanced design and process, and to provide a reasonable assurance that the plant design is in compliance with the general safety objectives of the EPR. A level 1 Probabilistic Safety Assessment (PSA) has been set-up. The only topic of the level 1 PSA is the core damage assessment when the fuel elements are in place in the reactor vessel. Allowance is made for internal events only, including loss of off-site power or water supplies. The all plant conditions are considered from power states to reactor coolant system open to shutdown conditions. The EPR PSA is modeled with a computer tool which enables Boolean reduction and so takes into account all dependencies between systems as common pipes, power supplies, cooling and I and C. (author)