[en] For safety analysis purposes, the IRSN needs to assess the performance and limitations of nondestructive test (NDT) methods being used in the nuclear industry. Numerical simulation is one of the tools that is suited to such assessments. This approach can improve understanding and facilitate analysis of the physical mechanisms involved in several types of NDT (ultrasonic, radiographic and eddy current techniques). For many years, the IRSN has participated in developing the numerical simulation functions required for its own safety analyses. These functions have been integrated into the CIVA NDT platform developed by the CEA and are now accessible to all other users, in particular nuclear facility operators. This papers presents various applications for numerical simulation in IRSN safety analyses and describes R and D currently being conducted on enhanced modelling of the relevant NDT methods. (orig.)

[en] X-ray/gamma ray radiography is a commonly used non-destructive evaluation method. For several years, a research program funded by the French Institute for Radioprotection and Nuclear Safety (IRSN), in partnership with French Alternative Energies and Atomic Energy Commission (CEA), studies gamma/X-ray simulation tools for evaluating NDE methods in the nuclear domain. In the context of this program, IRSN is particularly interested in the validation of the RT module of CIVA software, which deals with a large range of energy. The aim of this paper is to present results of CIVA RT tools validation. The study consists in a cross comparison between experimental and simulation results with a linear accelerator and a 150 mm thick mockup. These tests have been carried out on very small opening notches (20 microns to 150 microns).

[en] For more than 40 years, IPSN then IRSN has conducted research and development on nuclear safety, specifically concerning pressurized water reactors, which are the reactor type used in France. This publication reports on the progress of this research and development in each area of study - loss-of-coolant accidents, core melt accidents, fires and external hazards, component aging, etc. -, the remaining uncertainties and, in some cases, new measures that should be developed to consolidate the safety of today's reactors and also those of tomorrow. A chapter of this report is also devoted to research into human and organizational factors, and the human and social sciences more generally. All of the work is reviewed in the light of the safety issues raised by feedback from major accidents such as Chernobyl and Fukushima Daiichi, as well as the issues raised by assessments conducted, for example, as part of the ten-year reviews of safety at French nuclear reactors. Finally, through the subjects it discusses, this report illustrates the many partnerships and exchanges forged by IRSN with public, industrial and academic bodies both within Europe and internationally