Moderato: A Monte-Carlo radiographic simulation
Résumé
To ensure security on nuclear power plants, Electricité de France uses radiographic inspection for systemmatic pipe control. The extreme temperature and pressure conditions to which pipes are submitted may generate structural defects that must be detected and characterized. In order to provide valuable evidence on inspection capability, EDF is involved in the evaluation of a radiographic data simulation software (MODERATO). According to EDF’s requirements the whole radiographic process is modeled according to its physical behavior and incorporates new optimization adaptive techniques to decrease execution time so that computation time remains acceptable. According to EDF’s needs sources are Iridium and Cobalt ones. Objects and flaws of any size or shape, described by their CAD descriptions, can be simulated. It is suitable for simulating complex objects like casted elbows or welding. The detector consists in films and lead screens that can be combined. The model is completely microscopic and is based on Monte-Carlo simulation, so that each photon and electron behavior is computed one after the other. During evaluation, the blur resulting from scattering of photons in the absorbing material has been observed and measured on test radiographs; the detector response has also been studied. Resulting images are correct and are suitable for further applications like image processing or 3D reconstruction.