Theoretical calculations for the production of 99Mo using natural uranium in Iran

In the field of medical diagnostics, 99mTc with a half life of 6 h is widely used for medical purposes and produced from the decay of 99Mo (t1/2=66 h). The need for this isotope in the Iranian medical centres is about 20 Ci/week and is currently being imported. In this paper, the theoretical calculations related to the production of 99Mo, using natural UO2 and irradiating it within the Tehran Research Reactor are presented. The calculations are carried out by the use of the MCNP-4A and ORIGEN-2 codes. It is expected that following chemical separations, approximately 20 Ci/week of 99Mo may be obtained by irradiating 100 g of natural UO2 for a period of 7 days inside the reactor. This amount may be produced every other week due to the limitations on the reactor operation. Detailed calculations have been presented to the proper regulatory bodies for approval. Once authorized, the production is expected to begin in the first half of 2003.