Rapid immobilization of complex simulated radionuclides by as-prepared Gd2Zr2O7 ceramics without structural design

Abstract It is rather necessary to find a simple and rapid way to immobilize complex nuclear waste into stable ceramic matrix. In this work, complicated lattice occupation design was avoided through introducing complex waste into as-prepared host matrix. Two types of simulated TRPO (trialkyl phosphine oxides) wastes were introduced into as-prepared Gd2Zr2O7 matrix by spark plasma sintering (SPS) in 3 min. It is assumed that the waste composition, especially the contents of oxides with relatively low melting point (MoO3, RuO2 and PdO) and raw material for Gd2Zr2O7 (ZrO2), determines the final solubility. Moreover, the obtained compounds exhibit highly densified microtopography. Mo, Ru and Pd show more obvious enrichment with increased dopant while other doped elements show unobservable enrichment to the highest dopant. These results express a rapid and efficient way to immobilize oxides of high melting point into as-prepared host matrix without lattice occupation consideration.