Destructive and non-destructive evaluation of reinforced concrete dry casks affected by alkali-silica reactivity damage

Abstract

This article investigates the effect of alkali–silica reaction (ASR) damage on the structural performance of reinforced concrete (RC) dry casks for spent nuclear fuel (SNF) storage. Dry casks have an initial licensed lifetime of 20 or 40 years with the possibility of an extension of another 40 years. Due to lack of a permanent storage facility in the United States, an extension of the service life of dry casks that are currently in use and that were designed for shorter service lives is a critical step. Deterioration of concrete due to ASR is a major concern as has been reported for some nuclear facilities. In this study, the effect of ASR aging on the tip-over response of a vertical RC cask is experimentally studied for the first time using 1/3-scale physical models. An accelerated aging method was used to represent the long-term degradation of the structure. A series of non-destructive tests were performed to monitor the aging progress. At the end of the aging period, the structural performance of the casks is evaluated experimentally under tip-over impact. The results are compared with data obtained from a tip-over test on an undamaged cask. In addition, a detailed finite element model of the cask is developed to simulate the tip-over impact in aged conditions.