放射性降下物中のタングステン-181,185の分離検出法

181, 185W is detected in the rain samples collected on December 25, 1968 at Niigata. A recommended procedure for rapid separation of tungsten from radioactive fallouts has been developed. No detectable amount of radionuclides other than tungsten can be found in a γ-ray spectrum of the counting sample obtaind through the present procedure.