A cask system failure is not a plausible scenario. A cask system is a passive system meaning it has no active components or moving parts like a motor, pump or cooler that it relies on to function. The canister is filled with inert helium gas so that there is no mechanism for internal degradation of the canister or the used nuclear fuel. The canister is fabricated using high grade nuclear stainless steel; it is a well-known fact that there is no failure mechanism for stainless steel to suddenly fail without any symptoms. In addition, cask systems are required to be monitored by the U.S. Nuclear Regulatory Commission as part of the cask’s aging management program to ensure that degradation, if any is found over the years, is detected and corrected.
