Ultrasonic examination for inservice inspection of light water cooled nuclear power plant components

Concerning the ultrasonic flaw detection test of electrical structures in nuclear power stations, stipulation has been made in the ordinances and notices of the Ministry of International Trade and Industry, but as for the ultrasonic flaw detection test carried out in in-service inspection now, these technical standards and ASME Section II ''Rules for in-service inspection of nuclear power plant components'' have been diverted. In the method of ultrasonic flaw detection test, recently the automation of measuring instruments and the techniques for measuring the size of defects have advanced. Japan Electric Association made the guideline for the concrete method of carrying out ultrasonic flaw detection test applied to in-service inspection, for complementing JEAC 4205 - 1986 ''In-service inspection of machinery and equipment for LWR power stations'', after the prudent deliberation based on the opinions and data from various fields. The guideline is composed of general rules, general matters, ultrasonic flaw detection methods for vessels and pipings, records, the analysis of test results. It stipulates about the ultrasonic flaw detection test using pulse reflection method. Explanation is attached. (Kako, I.)