Zircaloy
Zirconium alloys (Zircaloy-2/4) for fuel cladding and structural components. Low neutron absorption, high corrosion resistance in reactor coolant.
Zircaloy-4: Zr-1.5%Sn-0.2%Fe-0.1%Cr; optimized for PWRs. Zircaloy-2 for BWRs (adds Ni). Annual production ~5000 tonnes. Brittle transition at 800°C; replaced by M5/NDA in advanced designs.
Why it matters now
Legacy Zircaloy limits burnup in restarts; ATF alternatives support 2025-2026 life extensions for data center PPAs.