AFC (AREVA Fatigue Concept)-An Integrated and Multi-disciplinary Approach to the Fatigue Assessment of NPP Components

摘要

The prevention of fatigue damages is a crucial issue for NPPs (nuclear power plants). The AFC (AREVA fatigue concept) provides for a multi-step and multi-disciplinary process against fatigue during the design and operating phase of NPPs. The entire process of fatigue design is based on an installed FAMOS (fatigue monitoring system). In this way, realistic load data are available to manage the component ageing and enable the optimization of operating modes. The measured temperatures are processed via a FFE (fast fatigue evaluation). Thus, an online fatigue evaluation of the cumulative usage factor is performed after every operational cycle. This procedure gives a first fatigue status of the power plant. Furthermore, a DFC (detailed fatigue calculation) conforming to the code rules is carried out in order to determine the state of the plant at the highest loaded positions. These finite element analyses include determination of thermal transient and subsequent stresses and strains. Fatigue environmental factors are taken into account in these studies.