A new 124Xe irradiation system for 123I production

Abstract

Since 2001, the Nuclear and Energy Research Institute IPEN-CNEN has produced iodine123, weekly, using a manual irradiation system, fully developed in IPEN. Ultrapure 123I has been produced and distributed to hospitals and clinics, where several diagnostic imaging procedures are done for thyroid, brain and cardiovascular functions. Due to the short half-life and emission of low-energy photons, this radioisotope becomes suitable for diagnosis in children. In the present work, will be presented all the technical and constructive aspects of a new fully automated irradiation system, dedicated to 123I routine production, employing enriched xenon-124 gas as the target material. This new system consists of a target, a water and a helium cooling system, a cryogenic system, an electric power system, and a control and process monitoring unit, composed of a supervisory software, connected to a programmable logic controller via personal computer. In this new concept, there is no need for human interference during radioisotope production, reducing the possibility of eventual failures or incidents involving radioactive material. In this way, with this new system, a specific yield, of 2.70 mCi/µAh per irradiation was achieved, in validation essays of the system and, after three years of routine production of iodine-123, the system showed reliability and resilience.