Life Assurance of CANDU Calandria and Shield Tank Assemblies

Abstract

This paper contains a re-assessment of the potential degradation mechanisms for the calandria shield tank assembly (CSTA). The assessments are made in support of the design of future stations. With few exceptions, the design of CANDU CSTAs is such that a life of up to 60 years is readily attainable. Few degradation mechanisms have been identified that might require further analysis, design, or testing and inspection. The current calandria tube design, however; is one part of the CSTA which must be replaced before 60 years. Provisions will be made in future designs for either the replacement of calandria tubes at mid-life or the introduction of stiffer more sag resistant calandria tubes.