Structural integrity analysis of a BWR core shroud with an irregular distribution of cracks: Limit load analysis

Pablo Ruiz-López, Luis H. Hernández-Gómez, Guillermo Urriolagoitia-Calderón, María L. Serrano-Ramírez, Arturo Ocampo-Ramirez, Juan A. Beltrán-Fernández, Guillermo Urriolagoitia-Sosa

Resultados de investigaciones: Capítulo del libro/informe/acta de congresoContribución a la conferencia

Resumen

© Springer Science+Business Media Singapore 2017. Mexico has a nuclear power plant with two BWR reactors. Their internal components were manufactured with type 304 stainless steel. Since the initiation of their commercial operation, some relevant cracks have been detected through the periodic inspections of their internals components. Specifically, there have been crack found at the core shroud and jet pumps. The causes of such cracks have been: excessive vibration, wear, stress corrosion cracking and residual stresses, acting alone or simultaneously. There are several aspects that have to be considered in the evaluation of the structural integrity of the core shroud, for instance: its shape is a cylinder and its R/t ratio is in the range between 60 and 100, as well as the water environment and the neutron irradiation. The last one has modified the mechanical properties of the material. Besides, each circumferential weld has a different non-symmetrical and irregular distribution of cracks with various depths. These cracks are monitored every 18 months, only during the plant shutdowns. Furthermore, the potential unstable cracking of the lower circumferential welds could induce important safety consequences if a loss of coolant accident and an earthquake event are postulated. Due to these reasons, it is very important to apply or develop adequate analytical procedures that can provide fast and reliable results. These procedures must cover elastic-plastic fracture analysis and plastic limit load analysis. In this paper, a methodology for the plastic limit load analysis was developed. The critical limit load for any crack distribution was calculated with a great degree of confidence. Operating conditions were considered. The shape of the cracks varies and the evaluation depends on the geometry of the cracked cylinder. In the problem at hand, the neutral axis varies, as it translates and rotates simultaneously at every cracked cross section, depending on the loading condition. This situation was also taken into account.
Idioma originalInglés estadounidense
Título de la publicación alojadaStructural integrity analysis of a BWR core shroud with an irregular distribution of cracks: Limit load analysis
Páginas413-427
Número de páginas370
ISBN (electrónico)9789811016011
DOI
Estado de la publicaciónPublicada - 1 ene 2017
EventoAdvanced Structured Materials -
Duración: 1 ene 2017 → …

Serie de publicaciones

NombreAdvanced Structured Materials
Volumen33
ISSN (impreso)1869-8433

Conferencia

ConferenciaAdvanced Structured Materials
Periodo1/01/17 → …

    Huella digital

Citar esto

Ruiz-López, P., Hernández-Gómez, L. H., Urriolagoitia-Calderón, G., Serrano-Ramírez, M. L., Ocampo-Ramirez, A., Beltrán-Fernández, J. A., & Urriolagoitia-Sosa, G. (2017). Structural integrity analysis of a BWR core shroud with an irregular distribution of cracks: Limit load analysis. En Structural integrity analysis of a BWR core shroud with an irregular distribution of cracks: Limit load analysis (pp. 413-427). (Advanced Structured Materials; Vol. 33). https://doi.org/10.1007/978-981-10-1602-8_32