Expanding Plug Wedge Test for Evaluating Hoop Tensile Properties of Fuel Cladding

An expanding plug wedge test method was developed to determine hoop tensile properties of irradiated fuel cladding in a hot cell [1]. Ring specimens with the plug-wedge insert were fabricated based Finite Element Analysis (FEA) design. After several design and modification iterations, the protocol was validated for M5 and Zr-4 cladding. Results show that tested ring specimens have uniform radial expansion deformation in the gage section. The test data processing procedure was developed based on the energy approach to generate hoop stress-strain correlation. α factor estimated from FEA was used to remove dissipated friction energy. With the proposed method, optimized specimen design, and data processing procedure, the protocol validates that the measured piston load, plug extension, and ring radial expansion can be effectively and accurately converted into the hoop stress-strain curve for clad tubing structural material characterization. Validation proved that the expanding plug wedge test method is robust and can be easily performed.