The Carbon Matrices Made of Pyrolised Phtalocyanines as a Base for Encapsulation of the Long-Lived Nuclides of Iodine, Technetium and Minor Actinides

The creation and careful investigation of suitable materials and forms for transmutation of the long-lived radioactive waste (RW) is mainly in the starting stage. A new carbon material formed as a result of pyrolisis of bisphtalocyanine, Pc₂Me, gives a chance to solve this goal successfully. The pyrolysis takes place under an argon (Ar) atmosphere at temperature of 700 – 800°C. The release of atoms encapsulated inside this carbon matrix occurs only at temperatures above 1200°C, and a correlation between the efficiency of the atoms’ release and their atomic radius has been revealed. It is caused with creation of closed microcavities in the carbon skeleton during pyrolysis of MeC₂. Due to inert features and high thermostability of carbon, an inculcation of the long-lived radionuclides in these microcavities by means of their phtalocyanines pyrolysis gives unique opportunities for both their transmutation and storage. The first results on encapsulation within matrixes of radionuclides of europium (Eu), technetium (Tc), iodine (I) and “minor actinides” are presented. The efficiency of encapsulation is close to 100% for all studied elements excluding iodine, for the last one, it is near 85–90%. The results on thermochemical stability, leaching and other tests of these matrixes are presented.