A comprehensive transmutation study for steels considered in the selection of structural materials for magnetic and inertial fusion reactors has been performed in the IFMIF neutron irradiation scenario, as well as in the ITER and DEMO ones for comparison purposes. An element-by-element transmutation approach is used in the study, addressing the generation of: (1) H and He and (2) solid transmutants. The IEAF-2001 activation library and the activation code ACAB were applied to the IFMIF transmutation analysis, after proving the applicability of ACAB for transmutation calculations of this kind of intermediate energy systems.

Uncertainties in the prediction of the neutron induced long-lived activity in the natural elements from H to Bi due to activation cross section uncertainties are estimated assuming as neutron environment those of the HYLIFE-II and Sombrero vessel structures. The latest available activation cross section data are employed. The random variables used in the uncertainty analysis have been the concentration limits (CL's) corresponding to hands-on recycling, remote recycling and shallow land burial, quantities typically considered in ranking elements under waste management considerations. The CL standard value (CL{sub nom}), i.e. without uncertainties, is compared with the 95th percentile CL value (CL95). The results of the analysis are very helpful in assessing the quality of the current activation data for IFE applications, providing a rational basis for programmatic priority assignments for new cross sections measurements or evaluations. The HYLIFE-II results shown that a significant error is estimated in predicting the activation of several elements. The estimated errors in the Sombrero case are much less important.