FWLTB: a mathematical model to calculate the lifetime of the fusion reactor first wall

FWLTB is a computer program elaborated for simulating the First Wall Long Term Behaviour in a fusion reactor environment. It combines nonstationary thermoelastic analysis of the wall with long-term variation of the material performance characteristics. This program emerged from the steady-state model via the nonstationary model up to the long-term model, the latter being still under development. The most important results from each stage are reported. These concern the way of treating the plasma radiation and the influence of load and design conditions on the fatigue life of the wall. First results with the long-term model are presented, showing the effects of swelling and irradiation creep and their impact on long-term variation of the stress and strain fields