Session: OAC-04-01 Storage and Transportation of Radioactive and other Hazardous Materials - 1

Paper Number: 105833

105833 - Modeling a Spent Nuclear Fuel Cask Seismic Test 

The US Department of Energy Spent Fuel and Waste Science and Technology (SFWST) program is planning to conduct a series of full-scale shake table tests to simulate hypothetical earthquake conditions and record the response of surrogate spent nuclear fuel (SNF) assemblies in a canister dry storage system mockup. The shake table motions will represent a range of hypothetical earthquake conditions at hypothetical locations in the continental US to generally define the range of mechanical loads that SNF can be expected to experience during extended dry storage periods.  The earthquake conditions will represent seismic hazards in the 2,000-to-20,000-year return period range.

The test will use instrumented pressurized water reactor fuel assemblies with surrogate mass inside the fuel rods instead of radioactive fuel pellets. Dummy assemblies with similar mass and dimensions to actual fuel assemblies will occupy the rest of the fuel assembly locations in a SNF canister that holds 32 fuel assemblies. The canister will be located inside a mockup vertical concrete cask.  Instrumentation will record the motion of the major components of the complex dynamic system, and strain gauges will be used to record the cladding strain at select locations.  Preparations for the test require modeling predictions to identify the range of response of the system and to help select specific earthquake cases to be simulated on the shake table from a large set of potential cases.

This paper describes the pretest nonlinear finite element modeling efforts that have been completed to date, including cask system level modeling and fuel assembly modeling in LS-DYNA.  The cask system level models are critical for anticipating sliding or tipping of an unanchored cask during the test.  The fuel assembly model is needed to estimate the range of cladding strain response and fuel assembly structural response to be expected during the test and cladding strain measurements will be key metrics for model validation and the development of modeling best practices after the test is concluded.

Presenting Author: Nicholas Klymyshyn PNNL

Presenting Author Biography: Nick Klymyshyn is a mechanical engineer in the Nuclear Material Storage and Transportation Team of the Experimental and Computational Engineering Group at Pacific Northwest National Laboratory. His technical expertise is in structural mechanics and finite element analysis, which he uses to support DOE and NRC in their work related to the nuclear power industry, spent nuclear fuel storage and transportation, and energy efficient vehicle technologies.

Authors:

Nicholas Klymyshyn PNNL
Kevin Kadooka Pacific Northwest National Laboratory
James Fitzpatrick Pacific Northwest National Laboratory
Casey Spitz Pacific Northwest National Laboratory