Abstract: Processes for in-situ decontamination and recovery of metal from radioactive-contaminated metal which is contained in process equipment, including ancillary systems of process equipment, comprise two basic steps. In the first step, an acid decontamination solution is circulated through the equipment and in contact with the radioactive-contaminated metal for removing the radioactive contaminants and a first surface portion of the metal from the metal-containing equipment. In the second step, an acid digestion solution is circulated through the equipment for removing at least a second portion of the metal which is substantially free of radioactive contaminants. The present methods are particularly suitable for in-situ decontamination and recovery of nickel from radioactive-contaminated nickel diffusion barriers in the cascade converters of uranium gas diffusion plants.