ZERO THICKNESS AND REFERENCE DEMARCATING METHOD FOR THE DEPOSITION DETECTION OF CORROSION PRODUCTS IN PWR PRIMARY SYSTEM

摘要

A nondestructive detection method based on radiation detecting technology has been design to inspect the deposition of corrosion products in Pressurized Water Reactor (PWR) Primary system. The zero thickness and reference demarcating method could measure the thickness of the corrosion products deposited inside the pipeline without the γ attenuation coefficient of the pipeline, coolant and the corrosion products which are necessary in the normal Nondestructive detection yet hard to be controlled and accurately obtained. With this method, the wall thickness and the inner diameter of the pipeline are not required during detection. The thickness of the corrosion products could be measured by only five parameters which could be monitored on-site real time: the gamma intensity at Measured Angle I, the gamma intensity at standard angle I_0', the length of the demarcating sample Z, the gamma intensity through the sample of corrosion products I_p and the gamma intensity through the sample of coolant I_c. With this method, the space distribution of the corrosion products inside the pipeline could be measured outside intuitively and conveniently. This method could also be applied to research the transport mechanisms of corrosion products in PWR Primary system, as the reference of the study on Primary water chemical.