RECOVERY OF HAFNIUM RADIOISOTOPES FROM A PROTON-IRRADIATED TANTALUM TARGET

The Hf-178m2 nucleus, with its long half-life (31 y) and high-spin iso meric state (16(+)) is desired for new and exotic nuclear physics stud ies. The Los Alamos Radioisotope Program irradiated a kilogram of natu ral tantalum at the Los Alamos Meson Physics Facility in early 1981. A fter fifteen years of decay, this target was ideal for the recovery of Hf-178m2. There was more than a millicurie of Hf-178m2 produced durin g this irradiation and there has been a sufficient period of time for most of the other hafnium radioisotopes to decayed away. Traditionally , separation techniques for recovering hafnium isotopes from tantalum targets employ solvent extractions with reagents that are considered h azardous. These techniques are no longer condoned because they generat e a mixed-waste (radioactive and hazardous components) that can not be treated for disposal. In this paper we describe a new and unique proc edure for the recovery of hafnium radioisotopes from a highly radioact ive, proton irradiated, tantalum target using reagents that do not con tribute a hazardous waste component.