Development Status of Surface-Modified Fuel Cladding for ATF

Enhanced accident tolerant fuel (ATF) cladding can be defined as cladding that provides considerably increased response time in the event of a nuclear reactor accident, while providing performance similar to or better than that of the commercial Zr cladding during normal operation. In addition, an enhanced accident tolerance includes suppressed reaction with steam, resulting in lower hydrogen generation, while maintaining acceptable cladding geometry by increasing the strength during accidents. In light water reactors (LWRs), the fuel cladding should have excellent heating transfer and corrosion resistance characteristics, while preventing primary leakage of the fission products in fuel pellet. The major benefit of the surface-modified Zr cladding concept or coated cladding is the economics when compared to other concepts such as FeCrAl cladding, Mo-lined cladding, and SiCf/SiC cladding, because the commercial Zr-based alloy and manufacturing facility can be used continuously. However, the surface-modified Zr and cladding coating concepts require the development of coating materials and coating technology.