Radiographic simulation and validation studies on weld joints of annular tanks and cylindrical tanks

Abstract

The application of the radiographic simulation studies on the weld joints in nuclear fuel reprocessing tanks used for optimization of radiographic testing parameters. In the nuclear reprocessing plant, Annular and cylindrical tanks are used to store the reprocessed solution of the spent fuel pins from the reactor. These annular and cylindrical tanks were installed 15 years ago. AERB (Atomic Energy Regulatory Board) has requested for requalification of these tanks before commissioning. As part of the requalification of tanks, the volumetric NDE techniques were proposed to be used for evaluation of the weld joints in the tanks. Before carrying out the radiographic examination on the actual tanks, computer simulation of radiography was studied on standard weld pad. Radiographic simulation is utilized for various purposes in NDT. This radiographic diagnostic model utilized for study about incorporates a description of the radiation source, the interaction of radiation with test pieces and defects, and the detection process. The modeling results were validated with radiographic inspection carried out with weld pad sample of 6mm thickness. The error percentage in the optical density achieved between simulation and experiment radiographic inspection was ± 5%. Hence the optimization parameters using simulation for the weld pad helps to reduce the number of exposures, inspection time and increase defect detectability of the inspection.