Publications Details

Thermal-mechanical modeling of a generic high-level waste salt repository

Clayton, Daniel J.; Arguello, Jose G.; Hardin, Ernest; Hansen, Francis D.

Coupled thermal-mechanical, three-dimensional, finite-element analyses were used to evaluate generic design concepts for a repository in salt, for spent nuclear fuel and high-level waste. This work used heat generation by spent nuclear fuel (SNF) typical of that presently stored at reactor sites in the U.S. For waste packages containing 4-PWR SNF assemblies, the results show peak temperatures within previously identified ranges acceptable for salt media. Peak temperatures and maximum backfill consolidation occur at the package-salt interface. Significant consolidation of the backfill, and closure of the mined opening, is projected to continue after peak temperatures are realized. For larger 21-PWR SNF packages, the peak temperature could approach 450°C locally or lower, depending on the aging history of the fuel. This ongoing study suggests the feasibility of a SNF management strategy using decay storage and larger (e.g., 21-PWR) waste packages.