Graphite matrix used for preparation of molded article for storing radioactive waste, comprises graphite and crystalline bonding agent containing salt containing metal chosen from transition metal and metal of specific groups

摘要

A graphite matrix comprises graphite and crystalline bonding agent, and has activity of less than 1010 bq/m 3>. The content of graphite is more than 50 vol.% of graphitic matrix. The crystalline bonding agent comprises crystalline inorganic compound(s). The crystalline inorganic compound is salt containing metal(s) having oxidation state of more than 0. The metal is chosen from transition metal, inner transition metal, metal of main group 1 and metal of main group 2. The salt does not contain sulfur-containing compound, preferably nickel sulfide. Independent claims are included for the following: (1) preparation of graphite matrix; (2) use of graphite matrix for preparation of molded article containing graphite matrix and radioactive waste, for storing of radioactive waste; and (3) molded article.