Evaluation device for crevice corrosion

A material of a first tubular member comprising zirconium or a zirconium alloy is interposed between materials of second tubular members comprising stainless steel. In this case, a bending deformation is applied to the surface of the first tubular member that causes predetermined tensile stresses so as to result in various residual stresses. A sensor entirely applied with insulation seal except for the boundary between the first tubular member and the second tubular member is disposed in a coolant flow channel or a flow channel in parallel therewith. This is periodically taken out, the material of the first tubular member is separated from the material of the second tubular member, cross section of a bent portion is observed microscopically to determine a hydrogen concentration based on the hydride distribution amount. For the material of the second tubular member, presence of failures due to crevice corrosion is microscopically observed. The crevice corrosion in the pipe joint between the zirconium alloy pipe and the stainless steel pipe having various residual stress distribution is thus monitored and evaluated. (N.H.)