The thermal interaction of yttrium aluminosilicate glass with cerium, plutonium and uranium oxides at temperatures up to 1200 °C has been studied by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD), and secondary electron microscopy (SEM). The glass, a candidate for joining and sealing advanced fuel cladding materials, such as silicon carbide (SiC), undergoes a recrystallization process above 1000 °C providing a mixture that exhibits two melting points at 1379 and 1410 °C. Samples containing glass and actinide oxide mixtures did not form new phases, nor did the actinide oxides influence the recrystallization behavior of the glass.