Cladding for high performance fuel

Contemporary cladding for commercial Generation III (light water reactor) fuel is made from zirconium-based alloys. This family of materials has evolved dramatically over their similar to 50 years of existence, leading to an order of magnitude improvement in corrosion resistance. However, in the perspective of a further increased U-235 enrichment, or other modifications leading to a significantly higher fissile content of the fuel, other materials that are even more resistant to irradiation damage and corrosion may be required. Cladding materials which degrade more slowly in a severe accident scenario are also desirable The ongoing development of Generation IV technology includes new cladding materials, e.g., SiC composites, which could be "back fitted" into Gen III fuel, providing enhanced performance, economy and safety. Due to the greater complexity of Gen IV technology, in particular its reprocessing infrastructure, the cost of electricity will be higher than for a Gen III LWR operating on a once-through fuel cycle, comparing the true, un-subsidized economic bottom line. Calculations indicate that this financial unbalance, in favor of Gen III LWRs, may be retained for at least hundreds of years. In this perspective, it appears appropriate and attractive to focus more strongly on evaluating Gen IV cladding materials, e.g., SiCf/SiCm, composites, for Gen III fuel. (C) 2011 Elsevier Ltd. All rights reserved.