Hydrodynamic Parameters Study of Gas-Solid Fluidized Bed Reactor: Case of AUC Conversion to UO2

Smain  Korichi; Farid Benaouicha; Fatah Mernache; Samia Ladjouzi

Smain Korichi Atomic Energy Commission (COMENA), 02, Frantz Fanon Boulevard, P.O. Box 399, Algiers RP, Algiers, Algeria
Farid Benaouicha Fuel Technology Division, Draria Nuclear Research Center (CRND), P.O. Box 43, Draria, Algiers, Algeria
Fatah Mernache Fuel Technology Division, Draria Nuclear Research Center (CRND), P.O. Box 43, Draria, Algiers, Algeria
Samia Ladjouzi Fuel Technology Division, Draria Nuclear Research Center (CRND), P.O. Box 43, Draria, Algiers, Algeria

Keywords: fluidized bed reactor, fluidization velocity, pressure drop, calcination, reduction, AUC, UO2

Abstract

The fluidization technique is used for gas-solid interaction processes whenever high rates of heat and mass transfer between the two constituents is required. This work aims to contribute to the understanding of the hydrodynamic parameters of gas-solid fluidized bed reactors in the case of the conversion of AUC powder (ammonium uranyl carbonate) into UO₂ powder (uranium dioxide). The study focuses on the fluidization velocity effect on the pressure drop evolution during the fluidized bed process, as function of the temperature and type of gas used (pure N₂, pure H₂, and a 50% H₂–50% N₂ mixture). The study will also present the results of the gas flow rate variation as a function of temperature, as well as the results of the pressure drop variation as a function of the fluidization velocity, taking temperature as a parameter for pure N₂, pure H₂ and 50% H2-50% N₂ mixture. Calcination-reduction experiments were conducted, using a fluidized bed reactor to convert AUC powder into UO₂. These experiments examined the influence of process parameters on particle size, specific surface area, O/U ratio and porosity of the UO₂ powder produced. Using the optimized operating parameters, such as the fluidization velocity, gas flow rates, and treatment temperature of the fluidized bed reduction-calcination process, ensured the production of UO₂ powders with the required physicochemical characteristics.

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