Production of the 178m2Hf Isomer in a Nuclear Reactor

A study is performed of the production of the 178m2Hf isomer (T1/2 = 31 years) upon the neutron irradiation of natural hafnium in a water-moderated reactor with a neutron fluence of ~1022 cm−2. It is shown that the 178m2Hf isomer forms mainly in reactions between fast neutrons and isotopes 178Hf or 179Hf. The specific activity of the isomer in irradiated hafnium is around 2 kBq g−1.