الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Nuclear facilities normally subjected to a numerous niles regarding radiation protection, nuclear safety, and accountability for and control of nuclear materials handled as one of the nuclear safeguards requirements. Ammonium Polyuranate (APU) is considered as one of the most important material in nuclear fuel fabrication. In the present study, different physico-chemical processes involved dunng the precipitation of ammonium polyuranate in an isothermal Semi-batch systen were invest i ga ted Thermal analysis technique was used to investigate the thermal behavior of the prepared ammoni uni polyuranatcs at different experimental conditions. A chemical reactions scheme describing the precipitation system was proposed. Chemical reactions kinetics were evaluated based on the flndiiig that polymerized ion formed upon ammonium hydroxide addition accompanied by color deepening and has a single maximum absorbance at a wave length of 420.6 nm. Nucleation rate, agglomeration kernel, and population density distribution functions were evaluated experimentally based on particle size analysis data using a gravitational sedimentation technique. A mathematical model that describes the dynamic behavior of the aminonium polyuranate Precipitation was developed. 1 he model is built of a set of non-linear ordinary differential and algebraic equations representing the volume change in the system, overall mass balance, component balance, chemical reactions rates, population balance, average volumetric growth rate, nucleation rate, agglomeration rate, and population density distribution. The model’ equations were sol\ cd using a FOR’IRAN—QO computer code, based on Runge—Kutta 4 algorithm.
Comparisons ol the model outputs with the experimental data over a iiine set oi experiments at different temperatures and initial uranium concentrations ol a total of 72 inns were carried out. The proposed mathematical model could be used as a tool to represent the aninioniuni polyuranate precipitation system.