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Seaside nuclear power plants have to face the ageing of nuclear reactor cooling piping systems. In order to minimize the duration of the production unit shutdown, maintenance operations have to be planned well in advance. In a context where owners of infrastructures tend to extend the life span of their goods while having to keep the safety level maximum, Oxand brings its expertise and know-how in management of infrastructures life cycle. A dedicated methodology relies on several modules that all participate in fixing network optimum replacement dates: expertise on ageing mechanisms (corrosion, cement degradation...) and the associated kinetics, expertise on impacts of ageing on functional integrity of piping systems. predictive simulation based on experience feedback, development of monitoring techniques focused on actual threats. More precisely, Oxand has designed a patented monitoring technique based on optic fiber sensors, which aims at controlling the deterioration level of piping systems. This preventive maintenance enables the owner to determine criteria for network replacement based on degradation impacts. This approach helps the owner justify his maintenance strategy and allows him to demonstrate the management of safety level. More generally, all monitoring techniques used by the owners are developed and coupled to predictive simulation tools, notably thanks to processes based on Bayesian approaches. Methodologies to evaluate and optimize operation budgets, depending on predictions of future functional deterioration and available maintenance solutions are also developed and applied. Finally, all information related to infrastructure ageing and available maintenance options are put together to reach the right solution for safe and performing infrastructure management.

EDF controls more than 150 high dams (more than 20 m in height). It is a legal requirement to inspect them while they are being emptied every ten years. In order to limit the negative effects on the local environment and to reduce the lost of production, this emptying can be replaced with a remotely operated vehicle (ROV) inspection which would give a clear view of the portion of the dam underwater. During the last 18 months, EDF and COMEX company have considerably improved the inspection's procedure by ROV by: the use of a Super Achille ROV with a mechanical arm; the measurement of the dimensions of the defaults with a SMC process as well as a laser; the positioning of the ROV by an acoustic signal system; the positioning of the defaults on a layout of the upstream part of the dam; the ability to draw up the report at the same time as the inspection by a specialized civil engineer; and the measurement of the water's turbidity before each inspection. Inspection carried out on the Laouzas' dam in September 1999 is a good representation of these new improvements. EDF's objective for the future is to achieve all inspections by ROV.