Heterogeneous breeding blanket experiment with lithium titanate and beryllium

An integral breeding blanket experiment has been done at Fusion Neutronics Source of JAERI with an assembly of three layers of lithium titanate, beryllium, and low activation ferritic steel F82H. The experimental assembly and the neutron source were enclosed in a SS316 stainless steel can and irradiated with D-T neutrons. The tritium production rate was measured with small Li2CO3 pellet detectors. The tritium production from7Li was estimated by means of the reactions32S(n, p)32P and35Cl(n, α)32P which have effective cross-sections similar to7Li(n, nα)T but are more sensitive methods. The neutron flux in the assembly was checked with activation foils. The measurement results were analyzed with the three-dimensional Monte Carlo code MCNP-4C and three different beryllium cross-section evaluations taken from FENDL/MC-2.0, FENDL/E-2.0, and EFF-3.03. The library FENDL/MC-2.0 was also used for the other materials in the assembly. All three beryllium libraries model the fast flux in the assembly well. Differences were seen for indium foils. An overestimation was observed for the tritium production.