METHOD FOR BURYING PLUTONIUM IN APATITE CERAMIC AND PRODUCT OBTAINED BY USING THIS METHOD Russian patent published in 2004 - IPC

FIELD: immobilization of radioactive wastes.

SUBSTANCE: plutonium burial block has phosphorosilicate apatite matrix whose chemical structure includes plutonium and radioactive lanthanides. Phosphorosilicate apatite formula is as follows: M_tCa_xLn_yHf_wPu_z-w(PO₄)_6-u(SiO₄)_uF₂, where M is at least one alkali metal; Ln is at least one cation chosen from lanthanides; t x, y, z, w, and u are such that and total number of positive charges afforded by cations of M, Cva, Ln, Hf, and Pu equals (20 + u). Phosphorosilicate apatite production process includes production of powder mixture, its milling to particle size below 50μ, and pressure sintering of mixture components. Powders are first mixed up without fluorinated chemical agent and then added to mixture to obtain final mixture of chemical agents. Then mixture is sintered to ensure reaction of its components at temperature of 1100 to 1600°C in neutral or reducing atmosphere applying pressure before or after sintering.

EFFECT: enhanced reliability of radio waste immobilization.

20 cl