Chemical Stability of Solidified Products Made from Incombustible Wastes by Plasma Melting

In order to investigate chemical stability of solidified products made from Low Level Radioactive Wastes (LLW) by plasma melting, a leaching test based on the MCC (Material Characterization Center)-3S Agitated Powder Leach Test Method was performed to determine Normalized Elemental Mass Loss (NL,) of both main components (Na, Al, Si, Ca, and Fe) of the solidified product and radioactive tracers (00Co, 137Cs, and 152Eu) incorporated into it. The results of leaching test indicated that NL, value was greatly affected by basicity defined as weight ratio of Ca0 to SiO2 in the solidified product, while effect of Fe0 concentration on NL, value was small. In the case of basicity less than 0.8, logarithm of NL, linearly increased with the basicity, implying that NL, value can be estimated by chemical composition of the solidified products.