(FT/P2-5) R&Ds on Li2TiO3 Pebble Bed for Test Blanket Module in JAEA

H. Tanigawa1), T. Hoshino1), Y. Kawamura1), M. Nakamichi1), K. Ochiai1), M. Akiba1), M. Ando1), M. Enoeda1), K. Ezato1), K. Hayashi1), T. Hirose1), C. Konno1), H. Nakamura1), T. Nozawa1), H. Ogiwara1), Y. Seki1), H. Tanigawa1), K. Tsuchiya1), D. Tsuru1), T. Yamanishi1)
 
1) Japan Atomic Energy Agency, Naka-shi, Japan

Abstract.  In JAEA, a Test Blanket Module (TBM) with water-cooled solid breeder has been developing for in-situ experiments in ITER. In the present paper, we report recent R& D activities for the TBM. In order to analyze thermo-mechanical behavior in the blanket including the pebble bed, the average thermal expansion coefficient of the Li2TiO3 pebble bed has been experimentally obtained. The obtained data enable us to conduct thermo-mechanical calculation accurately. For the breeding material, the chemical stability of Li2TiO3 has been improved by Li2O additives. This leads to high temperature use and to high efficiency in the energy conversion in DEMO reactors. In the field of the neutronics, the activation foil method has been proposed to verify nuclear properties of the TBM. For the water-cooled blanket, tritium permeation into the coolant water is the key issue. The chemical densified coating on the F82H steel has been well developed and high permeation reduction factor is obtained. In accordance with the current design of the TBM and the refined analysis of tritium behaviour, tritium recovery system has been modified. Based on these achievements, test program in the TBM is discussed.

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