Development of oxide layer thickness measuring device for irradiated nuclear fuel rods in hot cell

It has been known that water side corrosion of fuel rods in nuclear reactor is accompanied with the loss of metallic wall thickness and pickup of hydrogen. This corrosion is one of the important limiting factors in the operating life of fuel rods. In connection with the fuel cladding corrosion, a device to measure the water side oxide layer thickness by means of the eddy current method without destructing the fuel rod was developed by KAERI. The device was installed on the multi function testing bench in the nondestructive test hot cell and its calibration was carried out successfully for the standard rod attached with plastic thin films whose thicknesses are predetermined. It shows good precision within 10% error