The invention relates to a
PUREX process for separating
technetium. The
PUREX process includes the steps: (1) co-decontamination and co-extraction: co-extracting
uranium,
plutonium,
neptunium and the
technetium in spent fuel
nitric acid solution into an organic phase and washing co-extraction liquid; (2)
plutonium and
neptunium reverse extraction: reversely extracting the
plutonium and the
neptunium in the co-extraction liquid into a water phase by reverse extraction agents S1 containing AHA and then adding
uranium supplement extraction agents for supplement extraction to obtain the water phase containing the plutonium and the neptunium and an
oil phase containing the
uranium and the
technetium; (3) technetium reduction and reverse extraction: reducing and reversely extracting the technetium in the
oil phase containing the uranium and the technetium into the water phase by reverse extraction agents S2 containing reducing agents and then adding uranium supplement extraction agents for supplement extraction to obtain a water phase containing the technetium and an
oil phase containing the uranium, wherein the oil phase containing the uranium enters a subsequent uranium purification process. The neptunium, the plutonium and the technetium are reduced step by step through a step-by-step reduction method, the technetium can be separated out, the trend of elements is simpler and more uniform, all the reducing agents are salt-free reagents, remaining reagents are easily damaged, and the subsequent process is less affected.