Groupe d’études et de recherche en analyse des décisions

Statistical Analysis for Life Cycle Management of Steam Generators

Frenando Camacho

As equipment and systems age, Life Cycle Management (LCM) analysis becomes an important tool in assessing and managing potentially life limiting degradation mechanisms. Adequate LCM analysis usually considers a range of inspection and mitigation strategies aiming to maintain or extend the technical and economic life of the equipment. The assessment of these strategies needs to reflect not only the deterioration rate of the equipment, but also the impact the mitigation strategies have on the equipment. Deterioration rates can be assessed based on historical inspection trends, but in general it is much harder to assess how different mitigation strategies may affect the deterioration. This talk will describe some of the statistical analyses carried out to develop models that could be used on the LCM of steam generators of nuclear reactors. In particular, we will discuss the data collection, parameter estimation and variable selection used to select a model suitable to assess the effect of different mitigation actions on the deterioration rate of tube pitting in the steam generators.(Joint work with Sandra Pagan, Ontario Power Generation Inc., Pickering, CANADA)