Framatome Gmbh

Societe Franco-Belge De Fabrication De Combustible - Fbfc

Franco Belge De Fabrication De Combustibles

Societe Franco-Belge De Fabrication De Combustibles-Fbfc

André Feugier

Bruno Mesona

Alain Yakoubi

Véronique Peres

Luc De Tollenaere

A conversion process for converting uranium hexafluoride into uranium dioxide includes the steps of hydrolysis of UFto uranium oxyfluoride (UOF) in a hydrolysis reactor () by reaction between gaseous UF6 and dry water vapour injected into the reactor (), pyrohydrolysis of UOFto UOin a pyrohydrolysis furnace () by reacting UOFwith dry steam and gaseous hydrogen (H) injected into the furnace (), extracting excess gas in the reactor () via a collecting device () comprising several filters (), periodically cleaning the filters () by injecting a neutral gas into the filters () from the outside to the inside of the reactor () to remove powder stuck on the filters (), and measuring the relative pressure in the reactor (). The conversion method further includes carrying out point cleaning of the filters () when the relative pressure in the reactor () exceeds a predetermined point cleaning threshold.

Method and facility for converting uranium hexafluoride into uranium dioxide

A method for converting uranium hexafluoride to uranium dioxide includes steps of hydrolysis of UFto uranium oxyfluoride (UOF) in a hydrolysis reactor () by reaction between gaseous UFand dry water vapour injected into the reactor (), and pyrohydrolysis of UOFto UOin a pyrohydrolysis furnace () by reaction of UOFwith dry water vapour and hydrogen gas (H) injected into the furnace (). The hourly mass flowrate of gaseous UFsupplied to the reactor () is between 75 and 130 kg/h, the hourly mass flowrate of dry water vapour supplied to the reactor () for hydrolysis is between 15 and 30 kg/h, and the temperature inside the reactor () is between 150 and 250° C.

A method of declogging at least one filter of a plant for manufacturing uranium oxide from uranium hexafluoride, including separating, from the wall of the filter, uranium oxyfluoride particles deposited, by a stream of inert gas such as nitrogen, injected into the filter, in a counter-currentwise direction to the flow of hydrofluoric acid.

Method and device for declogging filter

A substance in a condensed state, for example a powdered solid, is in continuous movement in the longitudinal direction () of a furnace (). A reactive gas mixture is brought into contact with the substance in the condensed state. A plurality of samples of the gaseous mixture are removed at a plurality of reference points () spaced apart from one another along the longitudinal direction () of the furnace (); each of the gas samples is analyzed outside the furnace to determine the composition of the gas mixture and for each point (), the extent of a chemical reaction between the condensed substance and the reactive gas mixture is deduced from the composition of the gas mixture at each of the reference points (). In particular, the apparatus comprises a sampling and injection rod () introduced into the furnace () and disposed in its longitudinal direction (). The invention is of particular application to modeling a rotary furnace () for converting uranium oxyfluoride into uranium oxides and for controlling the conversion reaction in the furnace ().

Method and apparatus for determining the progress of a uranium oxyfluoride conversion reaction in a furnace and for controlling the reaction

The conversion apparatus comprises in succession: a reactor provided with injectors of UF.sub.6, steam, and nitrogen so as to cause UO.sub.2 F.sub.2 to be formed by hydrolysis; a rotary tubular pyrohydrolysis furnace for transforming UO.sub.2 F.sub.2 into uranium oxide, and provided with heaters distributed in at least five zones; and a tail end for conditioning the oxide powder. The injectors comprise three concentric nozzles connected respectively to inlets for UF.sub.6, nitrogen, and steam, UF.sub.6 being fed to the central nozzle and nitrogen being injected between UF.sub.6 and steam.

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Chatuzange le Goubet, France

André Feugier