Session: OAC-04-02 Storage and Transportation of Radioactive and other Hazardous Materials - 2

Paper Number: 105981

105981 - Additive Manufacturing and Regulatory Testing of Canisters for Spent Nuclear Fuel Management 

The back end of the fuel cycle focuses on the interim storage, transportation, and final disposition of the spent nuclear fuel from nuclear reactors. Commercial light water nuclear power stations across the United States operate with fuel assemblies being irradiated for up to 6 years (planned) in the reactor pressure vessel.  After their planned irradiation, the fuel assemblies are moved to a spent fuel pool within the facility complex.  After the spent nuclear fuel is removed from the fuel pool, it is typically inserted into a welded metal canister that can be transferred between overpacks for storage, transportation and possibly disposal[1]. Most dry storage systems being used by industry today use dual purpose canisters (DPCs), designed use in storage and transportation overpacks, but not specifically designed for disposal. Triple purpose-canisters, designed for disposal in addition to storage and transportation, have also been researched. Traditional manufacturing methods for spent fuel canisters involve fusion welding along the length or circumference of the canister which results in high tensile residual stresses in the joint weld zone (WZ) and heat affected zone (HAZ).

In this paper, spent fuel canister designs were printed by wire arc additive manufacturing (AM) using the 316L SS welding wire to demonstrate: 1. Feasibility of spent nuclear fuel canister fabrication using this advanced manufacturing method, 2. Dynamic response of the additive manufacture canister design when subjected to the federally mandated Normal Conditions of Transport and Hypothetical Accident Conditions physical tests for Type B packages. This paper will focus on the canister printing design and structural tests. The AM 3D printed design, regulatory testing, and post-test evaluation of the canister tested to the 10 CFR 71.71 and 10 CFR 71.73 requirements will be presented. One AM canister design was subjected to the penetration, free drop, and puncture test. Before and after the dynamic structural tests, the AM canister design was scanned with a handheld scanner to capture a 3D CAD geometry to compare to the 3D printed canister design in the deformed shape. The scanned geometry was sectioned in areas with deformation and the cross-section profile was measured to determine accurate and repeated results of the deformed shape of the AM canister design.

 

[1] This is a technical paper that does not take into account contractual limitations or obligations under the Standard Contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (Standard Contract) (10 CFR Part 961). For example, under the provisions of the Standard Contract, spent nuclear fuel in multi-assembly canisters is not an acceptable waste form, absent a mutually agreed to contract amendment. To the extent discussions or recommendations in this paper conflict with the provisions of the Standard Contract, the Standard Contract governs the obligations of the parties, and this presentation in no manner supersedes, overrides, or amends the Standard Contract. This paper reflects technical work which could support future decision making by the U.S. Department of Energy (DOE or Department).  No inferences should be drawn from this presentation regarding future actions by DOE, which are limited both by the terms of the Standard Contract and Congressional appropriations for the Department to fulfill its obligations under the Nuclear Waste Policy Act including licensing and construction of a spent nuclear fuel repository.

Presenting Author: Oscar Martinez Oak Ridge National Laboratory

Presenting Author Biography: Oscar Martinez is a group leader at Oak Ridge National Laboratory. His group focuses on nuclear materials transportation, analysis, design, and testing. He received his Ph.D. from the University of Florida in Aerospace Engineering. His primary research interests are in solid mechanics, structural analysis, explicit dynamic computational modeling, mechanical testing of hazardous material shipping containers, and transportation of radioactive material shipping containers.

Authors:

Oscar Martinez Oak Ridge National Laboratory
Dominic Giuliano Oak Ridge National Laboratory
Wei Tang Oak Ridge National Laboratory
Paul Nogradi Oak Ridge National Laboratory
Abiodun Adeniyi Oak Ridge National Laboratory
Lance Lowe Oak Ridge National Laboratory