Design and trial fabrication of a dismantling apparatus for irradiation capsules of solid tritium breeder materials

摘要

Irradiation experiments of solid breeder materials including Li_2TiO_3 have been being carried out in preparation for a test blanket module (TBM) of the International Thermonuclear Experimental Reactor (ITER). The present paper deals with design and trial-fabrication works for developing a dismantling apparatus for the irradiation capsules. The dismantling process leads to release of tritium which is left in free volumes of the capsule or in the breeder specimens. In the design of the dismantling apparatus, the released tritium is recovered safely by a purge-gas system during the cutting of the irradiation capsule by a band saw, and then the tritium is consolidated into a radioactive waste. Furthermore, an inner-box enclosing the dismantling apparatus works as a countermeasure of possible release of tritium in accidental events. Good performance of a trial fabrication model of the dismantling apparatus has been demonstrated by preliminary cutting runs using some mockups simulating the irradiation capsules. Thus, the present design of the apparatus, together with the trial mock-up runs, will contribute to the design of the TBM structure and to the planning of the dismantling process of the TBM.