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A conceptual design of Advanced Fusion Neutron Source, A-FNS, has been conducted to achieve early realization of fusion-like neutron irradiation test for fusion reactor materials in Japan. A-FNS provides eight test modules to obtain irradiation data for fusion reactor materials. Conceptual design activities on Blanket Functional Materials Test Module (BFMTM), Tritium Release Test Module (TRTM) and Activated Corrosion Products Module (ACPM) were described among the A-FNS test modules. Also, basic concepts of the sub-system cells for the TRTM and the ACPM were also discussed.

We proposed the neutron spectrum measurement system for Advanced Fusion Neutron Source (A-FNS). It is configured with fission chambers, Self-Powered Neutron Detectors, neutron activation systems using water flow, and activation monitors. In this study, we mainly investigated the multiple activation foils which are sensitive to high energy neutrons. We selected 14 main dosimetry threshold reactions based on specific A-FNS usage conditions. The reactions are as follows: 55Mn(n,2n)54Mn, 59Co(n,p)59Fe, 59Co(n,2n)58Co, 59Co(n,3n)57Co, 75As(n,2n)74As, 89Y(n,2n)88Y, 93Nb(n,2n)92mNb, 169Tm(n,2n)168Tm, 169Tm(n,3n)167Tm, 197Au(n,2n)196Au, 197Au(n,3n)195Au, 209Bi(n,3n)207Bi, 209Bi(n,4n)206Bi, and 209Bi(n,5n)205Bi. The dosimetry reaction rates were calculated using Monte Carlo code MCNP-5.15 with McDeLicious-11 and nuclear data libraries FENDL-3.1c, IRDFF-1.05 and EAF-2010. As for neutron-induced cross section data of the reactions in the high energy region, we clarified that there were limited experimental data, and proposed new experiment for their evaluations. Keywords: A-FNS, Neutron spectrum measurement, Activation foil, Dosimetry cross section

A plan of an advanced fusion neutron source (A-FNS) by using d-Li reaction is in progress at Rokkasho in Japan. We investigate multipurpose usages of the A-FNS in addition to fusion material irradiation test. Production of medical isotope 99Mo is considered as one of the usages. We conducted a conceptual study on a module for radioisotope production which was composed of a neutron spectrum shifter and a neutron reflector. We examined impacts of materials of the shifter and reflector on amounts of the 99Mo production, and their thicknesses. It was concluded that beryllium is the most suitable material both for the shifter and the reflector from the viewpoint of the 99Mo production. It was shown that we produced an enough amount of the 99Mo for the demand in Japan. We can apply natural molybdenum for this purpose. It was also shown that we could use a part of irradiation capsules in high flux test module, which was for the fusion material irradiation test originally, by using isotopically enriched 100Mo to meet that. Keywords: d-Li reaction, Fusion neutron source, Medical isotope, 98Mo(n,γ)99Mo, 100Mo(n,2n)99Mo, A-FNS