J. Phys. IV France
Volume 136, November 2006
Page(s) 263 - 271
Publié en ligne 22 décembre 2006
Corrosion and Long Term Performance of Concrete in NPP and Waste Facilities
V. L'Hostis, F. Foct and D. Féron
J. Phys. IV France 136 (2006) 263-271

DOI: 10.1051/jp4:2006136027

Risk management and maintenance optimization of nuclear reactor cooling piping system

L. Augé1, B. Capra1, M. Lasne1, O. Bernard1, P. Bénéfice2 and R. Comby2

1  OXAND, 36bis avenue F. Roosevelt, 77210 Avon, France
2  EDF-DPN-GMAP, Site Cap Ampère, 1 place Pleyel, 93207 Saint-Denis Cedex, France

(Published online 22 December 2006)

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.

© EDP Sciences 2006