Monte Carlo analyses of blanket neutronics experiments at FNS with latest nuclear data libraries

A series of neutronics experiments with mockups relevant to solid breeder water cooled blanket at FNS/JAEA have been analyzed with MCNP-4C, FENDL-2.1 and JENDL-3.3. Divergences of calculation results to experimental ones (C/Es) on tritium production rates (TPRs) from unity increase in the experiment with a neutron reflector made of SS316. These also increase at boundary between the breeder and beryllium layers. This suggests that there are some problems in back-scattering cross section data of nuclei included in SS316 and beryllium. The divergence can be improved by installation of water at this boundary. The C/Es on integrated TPRs are within 7% in experiments without a reflector