LIFE-METAL is a fuel-performance code to calculate the thermal and mechanical response of fuel elements in a fast-reactor environment. It incorporates a one-dimensional, steady-state heat-transfer analysis and a finite-strain-theory structural analysis based on generalized plane strain and the method of successive elastic solutions. An incremental approach is used so that temperatures, stresses, and strains can be calculated during any specified history of reactor power cycling. Fuel-cladding and sodium-cladding chemical attack is treated by a cladding wastage model. Migration of fabricated and swelling porosities; fuel and cladding thermal expansion, elasticity, swelling, and creep; fission-gas release; and hot pressing are included in the analysis. The code has been developed to perform nuclear, thermal, and structural analyses of U-Pu-Zr fuel elements under steady-state and slow transient operating conditions. Based on input from core-wide neutronics and thermal-hydraulics codes, LIFE-METAL does a detailed analysis of the behavior of fuel and cladding in a single fuel element.