Speaker
Taishi Sugiyama
(Graduate school of energy science)
Description
DEMO reactor must achieve total TBR >1 with high level of accuracy and confidence in the design process. However there is no relevant neutron sources before ITER /TBM, and even in ITER, neutron field is considerably different due to the shield blankets surrounding TBMs. This study proposes verification technique to experimentally simulate reactor neutron field and evaluates its expected accuracy. A small blanket module with the titanium hydrides coated first wall can generate fusion neutron by 100keV level deuterium beam with reactor relevant spectrum and geometry for benchmark of neutronics calculation. Suitable materials for moderator and reflector surrounding the module further simulate the neutron field within the module. Tritium production profile was evaluated by a neutron transport calculation by MCNP and compared with the case of fusion reactor. A small module of 25πcm2 plasma facing surfaceF82H RAFM, lithium titanate for breeding material, water and Be multiplier are layered as a model. Titanium coating of 5 micrometer tritiated to TiT2 generates 108 neutrons /cm2s uniformly by a 100 keV, 1.3 mA/cm2 deuterium beam. Module is surrounded by 40cm thick graphite that was found to be sufficient to simulate the total neutron reflection. Neutron flux attenuates half orders in 5 cm of magnitude along with the axis, and spectrum and flux profile agreed well with that of volume neutron source and full torus blankets case. Typical tritium production profile agreed within error of 10 %. Total 9 hours irradiation was sufficient for the tritium production profile measurement in the breeder with a liquid scintillator. Difference between the point source and volume source was found to become negligible with the 25π cm2 footprint. The result of this study suggests that experimental verification of the breeding performance of the blanket is possible with small scale facility.
Co-authors
Ryuta Kasada
(Institute of Advanced Energy, Kyoto University, Gokasho,Uji,Kyoto, Japan)
Satoshi Konishi
(Institute of Advanced Energy, Kyoto University, Gokasho,Uji,Kyoto, Japan)
Satoshi Sato
(Fusion Neutronics Group Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-4 Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki-ken, Japan)
Taishi Sugiyama
(Graduate school of energy science, Kyoto University, Gokasho,Uji,Kyoto, Japan)
