Dynamic behavior of duplex stainless steel with improved chloride-induced stress corrosion cracking resistance in drop scenarios for dry storage containers

Abstract

This study investigated the safety and structural integrity enhancements in dry storage containers (DSCs) achieved using a novel duplex stainless steel with a composition of Fe-19Cr-4Ni-2.5Mo-4.5Mn, referred to as advanced duplex stainless steel for a canister of dry storage (ADCS). This material was developed to improve resistance to chloride-induced stress corrosion cracking. The safety and structural integrity of DSCs utilizing ADCS and conventional austenitic stainless steel (ASS) were comparatively evaluated using finite element analysis based on detailed DSC models for vertical, oblique, and horizontal drops under accident scenarios, in accordance with International Atomic Energy Agency and U.S. Nuclear Regulatory Commission regulations. The results confirmed that ADCS significantly improved impact resistance and reduced plastic strain under impact conditions. Consequently, DSCs incorporating ADCS offer higher safety and reliability during both transportation and storage than those using conventional ASS. Furthermore, by leveraging these advantages of ADCS, DSCs can be made lighter while maintaining safety and structural integrity. Additionally, strain-based evaluations, consistent with ASME BPVC Sec. III Div. 3, demonstrated that higher margins could be achieved using ADCS where plastic deformation occurred. This highlights that ADCS is a promising material for ensuring greater structural integrity and safety in DSCs.