[en] In-pile functional tests of tritium breeding blankets for fusion reactors have been planned by Japan Atomic Energy Agency (JAEA), using a test blanket module (TBM) which will be loaded in ITER. In preparation for the in-pile functional tests, JAEA has been being performed irradiation experiments of solid breeder materials including Li₂TiO₃, which is the first candidate of tritium breeder materials for the blanket of the demonstration reactor (DEMO) in a water-cooled solid-breeder design concept in Japan. The present report describes conceptual investigation and basic design of the dismantling process for irradiation capsules which were used in irradiation experiments by the Japan Materials Testing Reactor (JMTR) of JAEA. An irradiation capsule to be dismantled is comprised of a cylindrical outer-container (65mm in outer diameter) and an inner-container which is loaded with Li₂TiO₃ pebbles. In the present design, the irradiation capsule is cut by a band saw; the released tritium is recovered safely by a purge-gas system, and is consolidated into a radioactive waste form. Furthermore, an inner-box enclosing the dismantling apparatus has been designed as a safety countermeasure of possible tritium release from the dismantling apparatus in accidental events. The adoption of the inner-box has brought a prospect to be able to utilize an existing hot cell (β γ cell) equipped with usual wall material permeable to tritium, without extensive refurbishing of the cell. Thus, the present study has indicated the feasibility of the dismantling process for the irradiated JMTR capsules containing tritium. The results of the present investigation and design will contribute to the design of the TBM structure and to the planning of the dismantling process of the TBM. (author)