Prediction of reliability factors of the Temelin nuclear power plant secondary coolant circuit

A brief overview is presented of the expected reliability characteristics of the SKODA-design secondary circuit for WWER-1000 reactor units. The reliability factors calculated by structural analysis are determined for the secondary circuit as a whole as well as for the individual technological systems, the control system and the electric supply system. The analysis revealed that the turbine with the generator and the steam generator feed equipment are the major contributors to unavailability, whereas the control system and the high-power electric supply contribute effects which are at least one order of magnitude lower. The unit of the Temelin nuclear power plant can be expected to be shut down due to secondary circuit failures for 5.6% of the total time of its possible use for power generation. The reliability factors were also compared with those for comparable facilities abroad, and a good agreement was found for the main systems of the secondary circuit as well as for the secondary circuit as a whole. (Z.S.). 3 tabs., 9 refs