Integral experiment of induced radioactivity in D-T fusion neutron environment and validation of activation cross section library

Under ITER/EDA R&D Task T-218, an integral experiment on the induced radioactivity was conducted at the Fusion Neutronics Source (FNS) facility in JAERI. The objective was to provide experimental data for validating the inventory calculation codes and relevant activation cross section libraries to be used in the ITER nuclear design. Sample materials investigated were Al, Mg, Ti, V, Mn, Fe, Ni, SS-316LN, Cu, Zn, Nb, Mo, Ag, In, Sn, Hf, Ta, W and Pb. The corresponding neutron spectra at two locations were calculated by MCNP4A with JENDL-Fusion File based nuclear data library by modeling the experimental assembly precisely. The calculations with currently updated activation cross sections, JENDL-ACT96, FENDL-A1 and FENDL-A2, were carried out to compare the results with the experiment. The results for the comparison between the measurement and calculation of radioactivity are discussed in terms of the adequacy of calculation as far as the D-T neutron dominated neutron field is concerned.