With the development of nuclear power and national defense industry, the amount of radioactive waste increased. Actinides in high-level waste (HLW) presents high specific activity, long half-life and high toxicity. If not properly handled, it will seriously endanger the living environment of human beings. At present, deep geological disposal has been widely recognized [1–3]. To ensure long-term safety during disposal, one of the keys is to immobilize waste in a stable matrix to prevent nuclides migration or leakage. As the first barrier between high-level radioactive waste and biosphere, the safety and stability of the main matrix in a long time are particularly important.
Hatch et al.  first proposed minerals to fix radionuclides so that nuclear waste should return to nature like natural radionuclides, and to maintain long-term safety and stability. Now, Synroc is known as the second generation of matrix for immobilizing high-level radioactive waste. It has the characteristics of strong inclusiveness, high water resistance, low nuclides leaching rate, considerable thermal stability and good radiation resistance [5–8]. Up to now, high-alunite phases, titanium-based phases, silicon-based ore phases and its composite phase are recognized as candidate solidified bodies for long-lived radioactive waste [9–13]. With the aim of solidifying radioactive waste to nature, most of these researches concerned Synroc. Until 2007, B. I. Omel’yanenko et al.  proved the feasibility of using natural minerals to return radioactive waste to nature by studying both natural minerals and Synroc. However, a large amount of work, from material selection to performance evaluation, is still required.
This work chose natural magmatic granite as host matrix to simulated An4+ waste, since the rock integrity of granite is highly recognized by geologists all over the world. Granite is mainly composed of quartz, plagioclase, K-feldspar, biotite and hornblende etc. . And it has the characteristics of small porosity, low water content, poor water permeability, large elongation, and good stability, which contributes to prevent or delay the migration of radionuclides . In addition, granite belongs to a glass-ceramic matrix, which has the advantages of both glass and ceramics. The basic principle shows in Fig. 1. In this experiment, blank granite powder was sintered to find a suitable sintering temperature, and then Ce4+ was doped as simulated tetravalent actinide oxides to study the solidification behavior of natural magmatic granite [17–19]. The phase, micro-morphology and mechanical properties of the immobilization were characterized.