NDTnet 1998 Aug, Vol.3 No.8

Full-Text - Abstract

State-of-the-art Ultrasonic Inspection
This paper presents the state-of-the-art ultrasonic inspection of nozzle attachment welds (inspection nozzle, by-pass nozzles ect.) to the main re-circulation loops within nuclear power plants using an advanced inspection system. The advanced inspection system consists of an inspection robot (AIR-1) with 6 axis, control system based on Silicon Graphics workstation with RobCad (Technomatic) and FORCE Institute's new P-scan system (PS-4).

Off-site Preparation
Prior the ultrasonic inspection of the nozzle attachment welds, the inspection procedures have been prepared in detail. The ultrasonic techniques have been developed through tests on open test blocks with 'known' fabrication and service introduced defects. The pulse-echo technique is used for detection and time-of-flight diffraction technique is applied for height sizing. Through 3D modelling of the nozzle attachment welds, the procedures have been optimised, and scan paths have been generated by means of the UltraSim application software package. The automated scan path generation ensures that the sound beams are oriented perpendicular to the welds throughout the entire inspection. The NDT system has been verified through ultrasonic inspection from the outer surface of a full scale mock-up (cladded carbon steel) of the attachment nozzles with defects. Based on acceptance tests, performance demonstration and technical justification, the procedures have been approved for on-site inspection.

On-site Inspection
The inspection is performed with the remote controlled robot (AIR-1), which has video surveillance cameras installed. The planned scan paths are executed, and the ultrasonic A-scan data collected for 3D reconstruction. During data analysis the ultrasonic data can be viewed as 3D. B-scan or A-scans.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

Publication Contact:
7th ECNDT, Park Alle 345, DK-2605 Broendby, Denmark, Fax: +45 46 26 70 11, Email: 101373.3414@compuserve.com