Measurement of Hg-203 activity induced in LiPb breeder material in D-T like neutron field

Hg-203 (T1/2 46.59 days) produced from Pb isotopes by fast neutrons is one of the most important radionuclide dominating in Pb in fusion power plant a few months after irradiation. Pb in Li15.7Pb breeder material will be irradiated in the HCLL TBM model by high fluxes of 14 MeV D-T fusion neutrons during test in ITER. The objective of the present work was to validate available computational tools and nuclear data used for calculation of Hg-203 activity produced in Pb and LiPb material irradiated in 14 MeV D-T like neutron fields. The samples of Pb and LiPb were irradiated in several day long experiment performed at FNG Laboratory in Frascati. Hg-203 activity in samples was measured after complete decay of Pb-203 interfering radioisotope with the use of HPGe spectrometers. The MCNP model of the experiment was developed and neutron fluxes in each sample were calculated with the use of FENDL-2.1 transport library. Hg-203 activities in samples were calculated using two methods: FISPACT-2007 code with EAF-2010 library and based on MCNP calculated reaction rates (Pb-206(n, α) and Pb-207(n, n′α)) with the use of JEFF-3.1, JENDL-4.0 and FENDL-2.1 libraries. Finally, the experimental and simulated results were compared and C/E values with assessed uncertainties calculated. The C/E value for JEFF-3.1 and EAF-2010 is 0.85 and for JENDL-4.0 is 1.16. The results with the use of FENDL-2.1 data are nearly one order of magnitude overestimated against experiment.