Method of dismantling reactor core structural material

Upon conducting volume-reducing processing for constituent mateiral zircaloy of reactor core structures by decomposing them by means of pyrometallurgy, zirconium is recovered as zirconium oxide, while chromium, iron, nickel, etc. with remaining radioactivity are made into slags and separated in a volume-reduced state. That is, pure copper is made in a molten state and the surface of a copper bath is maintained in an inactive non-oxidative atmosphere, to suppress the occurrence of unnecessary reactions. When reactor core structural materials to be decomposed are charged into the pure copper bath maintained at 1200 - 1300 deg C, a uniform molten bath is obtained upto Cu 80% - Zr. Then, oxidative reaction mainly for zirconium is promoted in a reducing atmosphere to form Zr and free zirconium oxide is separated and removed due to the difference of the specific gravity relative to the copper bath. Further, oxidation with Cr, Fe, Sn, Ni, etc. is promoted in an oxidative atmosphere, oxides are caused to float due to the difference of the specific gravity relative to the copper bath, and then they are made into slags and recovered by separation. (K.M.)