Proceedings of the conference

Bazulin A.E. Samarin P.F. Tihonov D.S.

Certification of the ultrasonic inspection technique for austenite and composite welded joints in pipelines on the NPP

In the report features of inspection and certification of the technique for the automated ultrasonic inspection of welded joints with wall thickness from 5 to 20 mm and diameters more than 108 mm of pipelines in the NPP are given (“The Technique …”). “The technique …” has passed acceptance tests in JSC “Concern Rosenergoatom” in 2014 using test blocks. While “The Technique …” development for automated ultrasonic inspection optimization taking into account an inspected object configuration, defects position and orientation was used modeling in the program complex CIVA (development by the CEA company, France). The major requirement in the inspection parameters analysis was also reducing the time of the automated ultrasonic inspection without loss of reliability and accuracy of the revealed defects parameters measurement.

Flaw detectors with phased arrays like OMNISCAN, HARFANG, AUGUR-ART, etc., complying necessary technical requirements can be used to make inspection by “The Technique…”. In the AUGUR-ART system developed in SPC ECHO+ Ltd. fast and effective algorithms of acoustic images reception of interior metal capacity with determination of actual geometrical sizes of the defects are used. Keeping of starting data and data processing results in the specialized database is provided. It allows monitoring an inspection objects condition – to monitor changing of the defects sizes which revealed in while in-service and repair works, and to plan repair works.

“The Technique…” was approved in Rostechnadzor (Regulator) for results of pilot operation of “The Techniques…” in the conditions of scheduled preventative repair works on the operating NPP. According to the program work for scheduled preventative repair works automated ultrasonic inspection and radiographical inspection of more than 40 austenite and composite welded joints on the NPP were executed. The quality of inspected by automated ultrasonic inspection welded joints was estimated according to the requirements of federal regulations and the rules NP-084-15 [1] existing now. Parameters of defects were determined by automated ultrasonic inspection, and the comparative analysis of automated ultrasonic inspection results and radiographical inspection results were done.

Examples of defects images revealed by automated ultrasonic inspection and radiographical inspection are given in the report. Images of revealed by automated ultrasonic inspection defects have additional information about the position and the sizes of revealed defects.

One of the stages of “The Technique...” pilot operation was the production of the test blocks with defects. Test block was inspected by the automated ultrasonic inspection and the radiographical inspection methods. Metallography was executed. Acoustic images of the defects and the results of the comparisons with the destructive testing data are provided.

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