Preparation of technetium-99m (Tc-99m) isotope generators,used as sources of radioactive tracers for gamma ray scintigraphy in hospital nuclear medicine departments. Here at Amersham International,radioactive molybdenum-99 (a fission product of a nuclear reactor) is dispensed by remote control into the columns of the generators inside a "shielded facility". The glass windows contain a lead compound,which accounts for their yellow-green colour. Tc-99m is short- lived (its radioactive decay rate,or half-life,is 6 hours),so a generator fuelled by its longer-lived parent isotope,molybdenum-99,is utilised as a continuous,short-term source |