6. Feedback

With more than 350 light water reactors in operation worldwide for decades, AREVA has considerable experience feedback. At the end of 2007, AREVA had irradiated around 120,000 fuel assemblies and 29 million fuel rods in PWRs, most of them of the 17 × 17 design.

For many years now, our knowledge of the behavior of materials under such conditions has been refined, enabling us to improve fuel performance and better appreciate the margins available, but the interpretation of phenomena and their modeling continue to be the subject of major research and development efforts.

Knowledge has progressed a great deal thanks to :

• statistical information on complete cores with high irradiation rates;

• numerous on-site fuel tests;

• numerous...