AREVA NP's enhanced accident-tolerant fuel developments: Focus on Cr-coated M6 cladding

AREVA NP (Courbevoie, Paris, France) is actively developing several enhanced accident-tolerant fuelscladding concepts ranging from near-term evolutionary (Cr-coated zirconium alloy cladding) to longtermrevolutionary (SiC/SiC composite cladding) solutions, relying on its worldwide teams and partnerships,with programs and irradiations planned both in Europe and the United States. The most advanced and mature solution is a dense, adherent chromium coating on zirconium alloycladding, which was initially developed along with the CEA and EDF in the French joint nuclear R&Dprogram. The evaluation of the out-of-pile behavior of the Cr-coated cladding showed excellent results,suggesting enhanced reliability, enhanced operational flexibility, and improved economics in normaloperating conditions. For example, because chromium is harder than zirconium, the Cr coating providesthe cladding with a significantly improved wear resistance. Furthermore, Cr-coated samples exhibitextremely low corrosion kinetics in autoclave and prevents accelerated corrosion in harsh environmentssuch as in water with 70 ppm Li leading to improved operational flexibility. Finally, AREVA NP has fabricated a physical vapor deposition prototype machine to coat full-lengthcladding tubes. This machine will be used for the manufacturing of full-length lead test rods in commercialreactors by 2019. KCI Citation Count: 17