THERMAL FATIGUE-CRACK GROWTH - MODELING AND EXPERIMENTAL-VERIFICATION

The first wall of tokamak type fusion reactors suffers from thermal fa tigue damage as the result of discontinuous loading due to plasma disr uptions. The Institute for Advanced Materials launched a generic therm al fatigue research project aimed at the numerical modelling, and at i ts experimental validation, of the lives spent in growing a crack to f ailure in components subjected to cyclic temperature gradients typical of NET. The experimental testing facilities consist of an out-of-pile and an in-pile rig for measuring the crack growth rate in tubular com ponents exposed to thermal fatigue conditions in a neutron free condit ion and under neutron irradiation in the HFR reactor, respectively. Te st results in the neutron free environment on 316L steel considered fo r first wall application in NET serve as a thermal fatigue life data b ase, and as a basis for the verification of the model prediction of cr ack growth rates under LEFM conditions.