NOVELTY - The apparatus has an anaerobic tank (110) storing wastewater containing wastewater in anaerobic condition. A microorganisms purification tank (120) comprises a metal reducing-bacteria supply source, an electron donor and a copper-ion supply source, where radioactive iodine and copper ions are bonded together by metal reducing bacteria to form copper iodide that is precipitated in the microorganisms purification tank such that the radioactive iodine in the wastewater is removed as sludge. A transfer pipe (10) connects the anaerobic tank and the microorganisms purification tank.    USE - Radioactive waste-water purification apparatus for purifying radioactive wastewater containing iodine nuclide biologically in a nuclear power station and a radioisotope utilization organization.    ADVANTAGE - The apparatus allows the radioactive iodine and copper ion to be bonded together by metal reducing bacteria to form copper iodide that is precipitated in the microorganisms purification tank such that the radioactive iodine in the wastewater is removed as sludge, so that process volume of secondary radiation substance in a purification process of wastewater can be decreased, thus enabling process of high level radioactive wastewater without releasing the wastewater from which radionuclide is removed, and hence preventing exposure radioactivity in processing course of the radioactive wastewater while enabling automation operation in purification process.    DETAILED DESCRIPTION - The metal reducing-bacteria supply source is a culture solution containing metal reducing-bacteria powder or metal reducing bacteria. The electron donor is selected from a carboxy-group containing organic acid, sulfonic-acid-group-containing organic acid and hydrogen gas.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block diagram of a radioactive waste-water purification apparatus.    Transfer pipe (10)    Sludge discharge pipe (30)    Anaerobic tank (110)    Microorganisms purification tank (120)    Sludge storage tank (124)