Fuel tube barrier gauge

摘要

An apparatus using X-ray fluorescence for gauging the thickness of a zirconium barrier layer on the interior surface of a zirconium alloy nuclear fuel tube is disclosed. A gamma radiation source coaxially positioned in the tube emits gamma rays which excite K-alpha and K-beta Sn X-ray in the zirconium alloy substrate. Fluorescent X-rays passing back through the barrier layer are detected by an X-ray detector coaxially positioned in the tube. Attenuation of the exciting gamma rays and the fluorescent X-rays by the barrier layer is used to determine barrier layer thickness.