Abstract: One of the major isotopes used in nuclear medicine is ^99mTc. ^99mTc for medical purpose is a decay product of ⁹⁹Mo, which is produced in research reactors from the fission of ²³⁵U. Uranium targets are being converted from highly enriched uranium (HEU) to low enriched uranium (LEU) to prevent nuclear proliferation. Advantages and disadvantages of various target designs are investigated and discussed along current disposal methods. In the present paper,some advice was also given for further exploration.