Tensile Test Techniques for a Nuclear Fuel Cladding in a Hot Cell

摘要

Modified transverse and longitudinal tensile test techniques are proposed to evaluate the mechanical properties of nuclear fuel cladding materials under a hoop and axial loading condition in a hot cell. The ring specimen with a gage length of 3 mm and a width of 2 mm is designed to limit a deformation within the gage section and to maximize the uniformity of a strain distribution at the gage section. The loading grip is designed such that a constant curvature of a specimen is maintained during a deformation. The contact surface is lubricated with a graphite lubricant (Model P-37, Molykote Co.). A dogbone specimen with a gage length of 25 mm and a gage width of 2.5 mm has been designed for the longitudinal tensile test. The grip is designed such that any slippage at the gripping section does not occur during a test. Through the tensile test of an unirradiated Zircaloy-4 cladding tube and an SUS 316 steel seamless tube, it is found that the proposed techniques are appropriate for an estimation of the tensile properties of an irradiated nuclear fuel cladding in a hot cell.