Considerations for structural analysis and evaluation of nuclear steam generator internals

Steam generators in a nuclear power plant extract heat from the primary coo lant and produce steam for power generation. While the pressure boundary co mponents of a steam generator contain high temperature and high pressure fl uid, the internal components (or simply referred to as internals) provide s tructural support to the tube bundle and allow circulation of secondary sid e fluid (water) and separation of steam from the steam water mixture. Prope r design of the internals is important for safety of nuclear power plants s ince the steam generators also act as a primary heat sink. Evaluation of th e internals is also important for plant Life management and plant Life exte nsion studies. There are set rules and standards for design and evaluation of pressure boundary components. However, there appear to be no such rules or such rules are not commonly available for structural design of the inter nals. This paper provides a methodology for structural analysis and evaluat ion of the internals. A brief description of the internals and various aspe cts of the analysis with reference to loading, stresses, seismic modeling a nd damping values to be considered for evaluation are included in this pape r. (C) 2001 Elsevier Science Ltd. All rights reserved.