Ultrasonic inspections in the fabrication of the ITER vacuum vessel sectors

The vacuum vessel is one of the most critical components of ITER facility. The fusion will take place within this component and it will undergo stringent conditions during operation. The vacuum vessel is a double wall torus made of nine sectors of stainless steel. Each sector is made of welded forged plates with the appropriate geometry and shape. Therefore, there are a large number of weldments that have to be controlled to assure they satisfy the specified quality requirements. In particular, the most challenging inspections that have to be qualified are the weld joints located in the outer wall with one surface access. The main objective of this paper is to describe the methodology for qualification and demonstration of ultrasonic inspection techniques for the examination of vacuum vessel weld joints. The qualification methodology and the ultrasonic inspections will be carried out in accordance with the CEN/TR 14748 and the RCC-MR Code 2007 Section III Examination Methods. The qualification of the inspection techniques will ensure they are capable of achieving the required performance under real industrial conditions.