Chemistry of inorganic compounds – Radioactive – Uranium compound
Patent
1996-03-20
1998-05-26
Miller, Edward A.
Chemistry of inorganic compounds
Radioactive
Uranium compound
423260, 423261, C01G 4300
Patent
active
057570876
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to processes for the oxidation of uranium hexafluoride.
Around the world there is increasing interest in the Applicants' Integrated Dry Route (IDR) kiln process for the conversion of UF.sub.6 into UO.sub.2. Features of the process are the subject of prior patents GB 1341379 and GB 2064503. With customers in 10 countries already benefiting from licensed use of the IDR process, its reliability and its ability to produce several different nuclear fuel types are well known. Since its 1969 introduction to the Applicants' Springfields site the IDR process has been used in fabrication of fuel for use in for Light Water Reactors (LWR), Heavy Water Reactors (HWR) and Advanced Gas-cooled Reactors (AGR).
BACKGROUND OF THE INVENTION
What makes the IDR process remarkable is that it converts uranium hexafluoride into ceramic grade uranium dioxide in just one processing vessel. This is in contrast to other wet or dry routes, which can take up to six different processing stages in different vessels to achieve the same result. Consequently, the Applicants' IDR process is the most direct and economic conversion route.
In addition, the IDR process is very versatile. It produces an exceptionally pure uranium dioxide powder which can be used to meet the specific pellet requirements of the various fuel types required by different nuclear reactor systems. The powder can be used in fuels made with or without the addition of a binder, and the Applicants have also developed pore formers for the powder which allow the introduction of controlled porosity in sintered pellets, and the ability to control precisely the sintered density of the pellets produced.
The dry IDR process produces minimal effluents. Accordingly, the IDR process is well able to cope with increasingly stringent discharge limits and is eminently suitable for dealing with reprocessed uranium.
In the IDR process the gases to be reacted together, viz UF.sub.6 and dry steam, are injected together as an aerosol plume into a reaction vessel as described for example in Applicants' GB 2135058B. The purpose of the present invention is to improve the product throughput of the UF6 oxidation process used in the IDR process whilst maintaining product quality.
SUMMARY OF THE INVENTION
According to the present invention there is provided a process for the oxidation of uranium hexafluoride by injecting the uranium hexafluoride and an oxidant gas together into a reaction vessel to form a plume characterised in that a plurality of the said plumes are formed together in the same vessel, the plumes mutually contributing to a circulating product formation stream in the said vessel.
The process may include the establishment of three or more plumes simultaneously contributing to the reaction between the gases in the reaction vessel.
The oxidant gas may comprise steam.
The process may be one in which the product is formed as a particulate solid as in the prior art. The product particles may initially be formed as dendritic particles which may be recirculated in the reaction vessel to promote seeding, growth, agglomeration and aggregation of the required product particles, the plumes thereby contributing to the product formation process in the vessel.
The reaction vessel may include an enclosure providing a region of excess volume which facilitates the recirculation process. Such a region per se is known in the prior art as in the IDR process where it is provided by a so-called disentrainment hopper.
A rotating mechanism such as a scroll structure also known per se in the prior art may be employed in the reaction vessel also to assist in the recirculation process as well as in the delivery of product particles to the outlet of the reaction vessel.
Where the reaction vessel includes an enclosure providing a region of excess volume at least one of the plumes may be established in the said region. Another of the plumes may be established in a part of the reaction vessel which is substantially level with the outlet region for the react
REFERENCES:
patent: 3790493 (1974-02-01), Dada et al.
patent: 3969477 (1976-07-01), Keith et al.
patent: 3970581 (1976-07-01), Jeter et al.
patent: 4005042 (1977-01-01), Dada
patent: 4031029 (1977-06-01), Colter et al.
patent: 4090976 (1978-05-01), DeHollander et al.
patent: 4112055 (1978-09-01), Artaud
patent: 4397824 (1983-08-01), Butler et al.
patent: 4698214 (1987-10-01), Linz et al.
patent: 4803056 (1989-02-01), Morris et al.
patent: 4812166 (1989-03-01), Saiki et al.
Carter Robert
Semeraz John Terry
British Nuclear Fuels PLC
Miller Edward A.
LandOfFree
Oxidation of uranium hexafluoride does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Oxidation of uranium hexafluoride, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Oxidation of uranium hexafluoride will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1964925