The US Department of Energy’s Spent Fuel and Waste Science and Technology (SFWST) program is investigating the mechanical loading of spent nuclear fuel (SNF) to close knowledge gaps and inform the range of relevant loads for mechanical testing of irradiated SNF. The SFWST program has performed full scale dynamic testing of multimodal transportation and cask drop scenarios related to normal conditions of transportation.
Currently, spent nuclear fuel (SNF) is stored in onsite independent spent fuel storage installations (ISFSIs), which are dry storage facilities, at 55 nuclear power plant sites. Because the SNF will be stored at ISFSIs for an extended period of time, there is growing concern with regards to the behavior of the SNF within these dry storage systems during earthquakes. To address these concerns, SNL under the Spent Fuel Waste Disposition (SFWD) program is planning to conduct a series of earthquake shake table tests. The goal of this test program is to determine the strains and accelerations on fuel assembly hardware and cladding during earthquakes of different magnitudes to better quantify the potential damage an earthquake could inflict on spent nuclear fuel rods.
The shake table experiments are designed to consist of one dry cask sitting on a concrete pad poured over the platen of the shake table. The effects of the underlying soil as well as of the neighboring casks, as in an actual ISFSI, will be numerically simulated through Soil-Structure Interaction (SSI) analyses and applied as input motion to the shake table.
Researchers at Pacific Northwest National Laboratory (PNNL) and at SC Solutions (SCS) are developing explicit dynamic finite element models of SNF and SNF cask systems to support the shake test program. Vertical and horizontal SNF canister storage systems are being modeled with a range of features to explore the structural dynamics of the canister systems, and to ultimately make pre-test predictions of their response to shake table excitation. This presentation will describe PNNL/SCS’s current progress in finite element modeling the SNF cask systems to inform the test plan. It will also cover the remaining modeling steps needed to support the test campaign and to briefly describe the next modeling steps after the test data is collected.