A number of global scaling expressions and local transport models are being investigated in order to propose a way to extrapolate the energy confinement time and temperatures profiles in ITER as well as estimate the uncertainties on these projections. Similar efforts are under way to extrapolate the H-mode power threshold and characterize operational limits such a Greenwald density limit or the Neoclassical island theory of beta limit.

This paper shows how this information can be combined by means of 1-1/2 D transport modeling into fusion performance predictions for ITER. Indeed, the energy confinement time is only one of several physics quantities required to determine the fusion power in ITER. One also needs to prescribe particle transport, to specify the characteristics of the H-mode edge transport barrier and to estimate the impurity content in the plasma in order to translate this information into fusion power. A sensitivity study is presented that estimates the impact of the various components determining the fusion power, the range of predicted fusion output and its compatibility with extrapolated operational limits.

The paper will also present time dependent simulations to address the issue of access into the H-mode, burn control and coupled control between divertor and core plasma. These studies are undertaken in such a way as to either be generic to any choice of local transport coefficients or to compare the predicted performance by using various local transport models.