Industrial photothermal system for the NDE of nuclear and industrial structures

Caulier, Yannick; AREVA NP; France

Caulier, Y.; AREVA NP; France

ID: ECNDT-0601-2018

Previous investigations demonstrated that the Photo-Thermal Camera (PTC) technique is able to reveal relevant anomalies in critical infrastructures, and has similar sensitivities as the dye penetrant testing (DPI) and magnetic particle inspection (MPI). The principle consists of generating a heat flux by locally heating the surfaces with a high-powered laser line.

This paper presents the developments of an industrial version of a PTC within the collaborative project ATHENA involving 8 partners (4 end-users, 2 integrators and 2 academics).

Different industrial domains have been covered by the project: the nuclear one (detection of cracks in small Inconel and Inox 316L nuclear parts of steam generators and vessels), hydraulic one (examination of Pelton wheels for the automatic detection of cracks and disbondings beneath the HVOF), and transport one (inspection of stainless steel turbine blades, and nickel alloy turbine disks).

The technical specifications were defined in order to meet the requirement of the 4 end-users. The ergonomy of the system was improved. The size was reduced by a factor of 2 and the weight by a factor 3. Automatic inspections can be fulfilled by placing the system on different manipulators. New signal processing algorithms permit to reveal critical anomalies in complete surface scans, with similar sensitivities than DPI and MPI, and to reduce the scanning time by a factor of 2. All the thermal responses of the defects considered in this project were simulated via COMSOL, permitting to define optimal parameters, based on an extended parametric study.

The system will be used after the end of the project (October 2017) for industrial inspections (rotor blades used for the energy production or petrochemical pipes welds). The commercial objectives are to sell 5 cameras within the first year, and to fulfill different onsite inspections.