Lifetime Analysis of Fusion Reactor First Wall Components

Linear elastic fracture mechanics is used to predict the growth of a semi-elliptical surface flaw through a thin-walled actively cooled 316 stainless steel first wall in a tokamak power reactor, which is subjected to pulsed surface heat fluxes, 14 MeV neutron irradiation and sputtering from particle bombardment. The results from an inelastic stress analysis, which includes thermal creep, irradiation creep, swelling, and wall thinning, are coupled to the crack growth calculations. The effects of temperature, R-ratio, threshold ΔK, neutron-induced embrittlement, creep crack growth and two-dimensional flaw shape changes are included. Predictions for a cylindrical blanket module with hemispherical first wall end cap indicate that severe reductions in lifetime can occur when radiation damage effects are included and demonstrate the need for high fluence data on da/dN and K_Ic.