Finite element modeling of acoustic emission in dry cask storage systems generated by cosine bell sources

Abstract

Dry cask storage system (DCSS) canisters used for the storage of high-level nuclear waste has begun to exceed the time for which they were originally intended. Therefore, efforts are being pursued by the nuclear industry to ensure that the structural integrity is maintained until arrangements have been made to transport the waste to a central repository. In this study, the technical basis of using acoustic emission monitoring for the detection of crack initiation and propagation in canister walls or welds in real time is investigated. The focus of this study, which is part of a larger project, is to develop the technical basis for using AE to monitor DCSS canisters for the initiation and propagation of stress corrosion cracking (SCC). SCC induced by a buildup of chlorides on the surface of the canister is postulated to be a potential degradation mechanism; however, there have been no known cases of this being found in practice. A small-scale type 304 stainless-steel specimen was utilized in this experiment to initiate and propagate stress corrosion cracking. Based on the experimental setup, a finite element model was built to investigate the feasibility of wave propagation modeling on small-scale type 304 stainless-steel specimens. Results indicate that wave propagation can be simulated by utilizing an excitation source. The model will later be applied to larger specimens that are similar in size to full-scale DCSS canisters.