Degradation Monitoring of G.A. Siwabessy Research Reactor's Secondary Cooling Pipe

Visual inspection, flaw detection and wall pipe measurement have been performed on secondary cooling system of G.A. Siwabessy reactor in order to evaluate the integrity of pipe structure as the implementation of ageing management programme. Visual inspection for internal surface was performed using CCD camera. The measurement was conducted using ultrasonic method and measurement locations were determined according guidelines in NPP. Measurement results show that wall thinning slightly occurred in secondary cooling system. Due to chemical element analysis of scale deposited on internal surface, it is known that wall thinning was caused by corrosion, by means of homogenous and pitting corrosion. No errosion-corrosion phenomenon was observed. In order to retard the wall thinning, it is needed to improve water quality to prevent the corrosion on the pipe. (author)