Prospects concerning 18O nuclide separation

In the last years the National R and D Institute for Isotopic and Molecular Technologies, ITIM at Cluj-Napoca in cooperation with ROMAG-PROD Heavy Water Plant at Drobeta Turnu Severin and National Institute of Research-Development for Cryogenics and Isotopic Technologies, ICSI, at Ramnicu Valcea carried out a study about the oxygen isotopes separation by means of facilities available in the country. At the same time there were analyzed the data published relating to separation and uses of the oxygen isotopes. In this work the main results obtained are presented as follows: the world consumption of 18O skyrocketed since 95% oxygen-18 enriched water is used as precursor to obtain 18F by proton reaction at cyclotron. This radionuclide after incorporated in glucose homologs is injected in the blood. When the glucose homologs labelled with 18 F is built up in some organ it can be visualized by PET (Positron Emission Tomography). At present PET is a major method of diagnosis in nuclear medicine; - Consequently the producers of 18O raised their production capacities and new producers occur. The favorite separation procedure is water rectifying under vacuum; - In Romania there exist availabilities for achieving a productive unit for 18O production. The water-rectification-under-vacuum technology was achieved and pushed up to industrial scale for final separation of heavy water. The technologic requirements for 18O enrichment are more stringent as the separation elemental factor is lower. However, the experience and achievements in the field of heavy water production in Romania represent a worth basis to start for refining the technology up to the level required by 18O separation. In case that a line of heavy water would become available this could be embodied within a 18O production cascade what would reduce substantially the investment cost. In addition, the 18O extraction from heavy water is about 2.5 times cheaper than the extraction from natural water while heavy water is available. As a bonus, the heavy water used for extraction of 18O gains in its nuclear quality as it gets depleted in 17O isotope, a spurious presence in the nuclear reactor