CA1197069A - Method for preparing a sinterable uranium dioxide powder - Google Patents
Method for preparing a sinterable uranium dioxide powderInfo
- Publication number
- CA1197069A CA1197069A CA000411251A CA411251A CA1197069A CA 1197069 A CA1197069 A CA 1197069A CA 000411251 A CA000411251 A CA 000411251A CA 411251 A CA411251 A CA 411251A CA 1197069 A CA1197069 A CA 1197069A
- Authority
- CA
- Canada
- Prior art keywords
- uranium dioxide
- dioxide powder
- compound
- ammonium
- heating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G43/00—Compounds of uranium
- C01G43/01—Oxides; Hydroxides
- C01G43/025—Uranium dioxide
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
- G21C3/42—Selection of substances for use as reactor fuel
- G21C3/58—Solid reactor fuel Pellets made of fissile material
- G21C3/62—Ceramic fuel
- G21C3/623—Oxide fuels
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Ceramic Engineering (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Disintegrating Or Milling (AREA)
Abstract
METHOD FOR PREPARING A SINTERABLE URANIUM DIOXIDE POWDER
ABSTRACT OF THE DISCLOSURE
The invention discloses an improved method for preparing a sinterable uranium dioxide powder for use and preparation of nuclear fuel wherein microwaves heat a start-ing material comprising a compound selected from uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate for a sufficient period to decompose the starting compound; continuing to heat the decomposed compound in a microwave induction furnace in reducing atmosphere until the decomposed compound further decomposes to uranium dioxide powder. The powder is then cooled in a reducing atmosphere.
The method may be practiced in a number of different atmospheres, such as an oxidizing atmosphere or a reducing atmosphere, to meet specific products needs. Desirable temperature ranges for practicing the invention are also practiced.
ABSTRACT OF THE DISCLOSURE
The invention discloses an improved method for preparing a sinterable uranium dioxide powder for use and preparation of nuclear fuel wherein microwaves heat a start-ing material comprising a compound selected from uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate for a sufficient period to decompose the starting compound; continuing to heat the decomposed compound in a microwave induction furnace in reducing atmosphere until the decomposed compound further decomposes to uranium dioxide powder. The powder is then cooled in a reducing atmosphere.
The method may be practiced in a number of different atmospheres, such as an oxidizing atmosphere or a reducing atmosphere, to meet specific products needs. Desirable temperature ranges for practicing the invention are also practiced.
Description
~9~7~6g BACKGROUND OF THE INVENTION
The present invention relates to an improved method for preparing a sinterable uranium dio~ide powder for use in nuclear fuel preparation and, more particularly, to the preparation of a sinterable uranium dioxide powder by microwave radiation in a microwave induction furnace.
Uranium dioxide is the fuel most commonly used in present day nuclear power reactors. Generally, uranium dioxide powder is pressed and ~intered to form pellets which are loaded into and sealed in slender, hollow metal tubes called fuel rods. It is a plurality of such fuel rods that establishes an accumulation of fissionable material in sufficient concentration to support sustained fission reactions within the core of a nuclear power re-actor.
A num~er of techniques have been developed for pre-pariny a sinterable uranium dioxide powder, generally the starting compound in a nuclear fuel pellet preparation process, the most common of which involves the decomposi-tion and reduction of ammonium diuranate or the ADU method.ADU is produced by precipitation from a solution of uranyl fluoride by the addition of ammonia and the ADU formed in this manner has a very fine particle size which carries through to uranium dioxide powder after thermal drying, decomposition and reduction in an electrical resistance furnace, radiant heat transfer dryer, kiln or a co~bina-tion thereof.
Another common method for the manufacture of uranium dioxide powder is the ammonium urànyl carbonate or AUC
method. The AUC is produced by precipitation from a solu-tion of uranyl fluoride by the simultaneous addition of NH3 and CO2; the RUC precipitated thereby is separatéd t'q' ~h 7~
from the mother li~uor by filtering and washing, and the uranium dioxide powder is formed by thermal decomposition of the AUC and subsequent reduction of the resulting U3O8 to UO2 in a reducing atmosphere. The thermal decomposition of the AUC and the reduction of the oxide into uranium dioxide powder in hydro~en or other reducin~ ~as is nor-mally carried out in an electrical resistance furnace or in two such units, such as the so-called vortex-bed furnaces.
Still another method for the manufacture o uranium dioxide powder is the ura~yl nitrate hexahydrate or UNH
method. The UNH method proceeds by starting with uranyl nitrate hexahydrate,UO2(NO3)2.6H2O, then heating and de-composing the compound in an electrical resistance furnace to form UO3, oxides of nitro~en and water vapor. The UO3 is then heated in an electrical resistance furnace in a hydrogen reducing atmosphere to form uranium dioxide pow-der and water vapor.
The prior art processes for preparing uranium dioxide powder have in common the use of standard electrical resis-tance or combustion-fired heating furnaces during the decomposition and reduction steps, that i5, the decomposi-tion to UO3 or U3O8 followed by reduction to uranium di-oxide powder. Alternatively, uranium bearin~ compounds are processed primarily utilizing radiant heat transfer dryers and kilns. It is the object of the present inven-tion to replace the conventionallv used electrical resis-tance furnace, radiant heat transfer dryer and kiln with microwave induction furnaces.
Heretofore, microwave induction has been used as a heating mechanism almost entirely via the susceptance of the water molecule to microwave radiation, that is, the use of microwaves for the heating of materials has been centred on the effects that microwaves have on water ~g~9 molecules. Microwaves cause rapid changes in the polariza-tion of the water molecule, thereby generating heat. The invention herein described discloses that uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbo-nate also suscept to microwave radiation, generating heat.Accordingly, the electrical resistance furnace, radiant heat transfer dryer and kiln, above discussed, can be replaced by microwave induction furnaces during the prepa-ration of uranium dioxide powdervia the ADU, AUC and UNH
powder preparation processes.
The present invention overcomes many of the short-comings of the prior art heating devices by decreasing material heatup time, allowing a greater range of process-ing temperatures, shortening processing times, lowering fluoride impurity levels, improving the ease in handling gelatinous ADU or AUC filter cakes, conserving energy by generating heat entirely within the target material, find-ing greater utility in remote locations required for nuclear fuel processing and providing a ceramically active, sinter-able uranium dioxide powder product.
SUMMARY OF THE INVENTION
The present invention relates to an improved methodfor preparing a sinterable uranium dioxide powder for use in nuclear fuel preparation utilizing the concept of micro-wave radiation in a microwave induction furnace. Typically,a starting compound is selected from the group consisting of uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate. The selected starting compound is then heated in a microwave induction furnace for a period of time sufficient for compound decomposition. The decomposed compound is then heated in a microwave induction furnace in a reducing atmosphere for a period of time suf-ficient to reduce the decomposed compound to uranium dioxide powder, after which, the uranium dioxide powder is cooled 6~
in a reducing atmosphere. After cooling, the powder is available for use in a nuclear fuel preparation process.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure.
E`or a better understanding of the invention, i~s operating advantages and specific results obtained by its use, reference should be made to the descriptive mattex in which there is illustrated and described a typical embodi-ment of the invention.
DETAILED DESCRIPTION OF T~IE PP~EFERRED EMBODIMENT
A sinterable uranium dioxide powder to be used in anuclear fuel preparation process is produced by first selecting a commercially available starting material from the compound group of uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate. The selected start-ing material or compound is then heated in a microwave induc-tion furnace for a period of time sufficient to decompose the material, the composition of which may have a uranium oxide stoichiometric range of from UO3 to U3O8. The pre-ferred decomposition end product is U3O8 and the decompo-sition may be conducted in either an oxidizing, air, 2' or the like, mixed air-stream, or an inert atmosphere.
The decomposition step is conducted at a heating tempera-ture in the range of about 400 to 600C when uranyl nit-rate hexahydrate is selected as the starting compound.
The decomposition heating temperature is conducted in the ranye of about 350 to 450C when either ammonium diuranate or ammonium uranyl carbonate is selected as the starting compound. The decomposed compound is then heated in a microwave induction furnace in a reducing atmosphere con-sisting essentially of a hydrogen-nitrogen gas mix~ure, or the like, for a period of time sufficient to reduce the decomposed compound to uranium dioxide powder; the 6~
reduction step is conducted at a heating temperature in the range of about 450 to 550C notwithstanding -the start-ing material selected from the aforementioned compound group. The uranium dioxide powder i5 then cooled in a reducing atmosphere to approximately room temperature.
After cooling the powder is read~ for use in a muclear fuel preparation process.
Uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate were each subjected to microwave radiation in a microwave induction furnace at approximately 2450 MHz, the frequency of the standard kitchen-type micro-~ave oven, to determine the susceptance of each compound to microwave radiation. It should be understood thak, while a conventional microwave oven was selected for use because of its ready availability, other microwave induc tion fuxnaces operating at different frequencies would also be operable. Additionally, one oven or a plurality of ovens could be used for the decomposition and reduction processes. Each uranium compound readily suscepted, heat-ing rapidly. Other materials, however, such as niobia,alumina, silica, and graphite, when exposed to microwave radiation, while suscepting, did not exhibit the rapid heating found to be characteristic of the above compounds of uranium.
Uranyl nitrate hexahydrate crystals suscepted to microwave radiation in a microwave induction furnace in an oxidizing atmosphere by first forming a liquid as the hydrated water molecules were released, then decomposing in a 400 to 600C temperature range, progressively drying, releasing nitrous oxide gas and water ~apor and forming uranium trioxide (UO3). The UO3 was then heated to a temperature in the 450 to 500C range in a microwave induction furnace in a reducing atmosphere wherein water vapor was released and the UO3 was reduced to uranium di-oxide powder which was then cooled in the reducing 70~
atmosphere to about room temperature.
Ammonium diuranate, available as a filter cake,suscepted to microwave radiation in a microwave induction furnace in an oxidizing atmosphere by first releasing water and drying in the microwave field and then by de-composing in a 350 to 450~C temperature range, releasing ammonia gas and water vapor and forming U3O8. The U3O8 was then heated to a temperature in the 450 to 550C
range in a microwave induction furnace in a reducing atmosphere wherein water vapor was released and the U3O8 was reduced to uranium dioxide powder which was then cooled in the reducing atmosphere to about room teperature.
Ammonium uranyl carbonate, subjected to the condi-tions imposed upon ammonium diuranate, decomposed in much the same manner as did the ammonium diuranate, releasing gases of ammonia and water vapor with the additional release of carbon dioxide gas and forming U3O8. The reduc-tion of U3O8 to uranium dioxide powder, followed by cooling, proceeded as did the reduction and cooling of ammonium di-uranate.
Uranyl nitrate hexahydrate, ammonium diuranate andammonium uranyl carbonate decomposition and reduc-tion in a microwave induction furnace or furnaces is accomplished in processing times on the order of minutes rather than the hours customarily associated with the use of conven-tional electrical resistance furnacesO Additionally, the processing of a glossy or gelatinous filter cake does not hinder the microwave decomposition-reduction processes, the presence of such cakes lengthen process times in conventional furnaces and effect finished product ~uality.
Uranyl nitrate he~ahydrate, ammonium diuranate and ammoni-um uranyl carbonate processes in a microwave field produce a finished product o~ sinterable uranium dioxide powder suitable for use in a nuclear fuel preparation process.
~9~
While in accordance with the provisions of the statutes there is herein illustrated and described a specific embodiment of the invention, those skilled in the art will understand that changes may be made in the form of the invention covered by the claims, and that certain features of the invention may sometimes be used to advantage without corresponding use of the other features.
The present invention relates to an improved method for preparing a sinterable uranium dio~ide powder for use in nuclear fuel preparation and, more particularly, to the preparation of a sinterable uranium dioxide powder by microwave radiation in a microwave induction furnace.
Uranium dioxide is the fuel most commonly used in present day nuclear power reactors. Generally, uranium dioxide powder is pressed and ~intered to form pellets which are loaded into and sealed in slender, hollow metal tubes called fuel rods. It is a plurality of such fuel rods that establishes an accumulation of fissionable material in sufficient concentration to support sustained fission reactions within the core of a nuclear power re-actor.
A num~er of techniques have been developed for pre-pariny a sinterable uranium dioxide powder, generally the starting compound in a nuclear fuel pellet preparation process, the most common of which involves the decomposi-tion and reduction of ammonium diuranate or the ADU method.ADU is produced by precipitation from a solution of uranyl fluoride by the addition of ammonia and the ADU formed in this manner has a very fine particle size which carries through to uranium dioxide powder after thermal drying, decomposition and reduction in an electrical resistance furnace, radiant heat transfer dryer, kiln or a co~bina-tion thereof.
Another common method for the manufacture of uranium dioxide powder is the ammonium urànyl carbonate or AUC
method. The AUC is produced by precipitation from a solu-tion of uranyl fluoride by the simultaneous addition of NH3 and CO2; the RUC precipitated thereby is separatéd t'q' ~h 7~
from the mother li~uor by filtering and washing, and the uranium dioxide powder is formed by thermal decomposition of the AUC and subsequent reduction of the resulting U3O8 to UO2 in a reducing atmosphere. The thermal decomposition of the AUC and the reduction of the oxide into uranium dioxide powder in hydro~en or other reducin~ ~as is nor-mally carried out in an electrical resistance furnace or in two such units, such as the so-called vortex-bed furnaces.
Still another method for the manufacture o uranium dioxide powder is the ura~yl nitrate hexahydrate or UNH
method. The UNH method proceeds by starting with uranyl nitrate hexahydrate,UO2(NO3)2.6H2O, then heating and de-composing the compound in an electrical resistance furnace to form UO3, oxides of nitro~en and water vapor. The UO3 is then heated in an electrical resistance furnace in a hydrogen reducing atmosphere to form uranium dioxide pow-der and water vapor.
The prior art processes for preparing uranium dioxide powder have in common the use of standard electrical resis-tance or combustion-fired heating furnaces during the decomposition and reduction steps, that i5, the decomposi-tion to UO3 or U3O8 followed by reduction to uranium di-oxide powder. Alternatively, uranium bearin~ compounds are processed primarily utilizing radiant heat transfer dryers and kilns. It is the object of the present inven-tion to replace the conventionallv used electrical resis-tance furnace, radiant heat transfer dryer and kiln with microwave induction furnaces.
Heretofore, microwave induction has been used as a heating mechanism almost entirely via the susceptance of the water molecule to microwave radiation, that is, the use of microwaves for the heating of materials has been centred on the effects that microwaves have on water ~g~9 molecules. Microwaves cause rapid changes in the polariza-tion of the water molecule, thereby generating heat. The invention herein described discloses that uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbo-nate also suscept to microwave radiation, generating heat.Accordingly, the electrical resistance furnace, radiant heat transfer dryer and kiln, above discussed, can be replaced by microwave induction furnaces during the prepa-ration of uranium dioxide powdervia the ADU, AUC and UNH
powder preparation processes.
The present invention overcomes many of the short-comings of the prior art heating devices by decreasing material heatup time, allowing a greater range of process-ing temperatures, shortening processing times, lowering fluoride impurity levels, improving the ease in handling gelatinous ADU or AUC filter cakes, conserving energy by generating heat entirely within the target material, find-ing greater utility in remote locations required for nuclear fuel processing and providing a ceramically active, sinter-able uranium dioxide powder product.
SUMMARY OF THE INVENTION
The present invention relates to an improved methodfor preparing a sinterable uranium dioxide powder for use in nuclear fuel preparation utilizing the concept of micro-wave radiation in a microwave induction furnace. Typically,a starting compound is selected from the group consisting of uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate. The selected starting compound is then heated in a microwave induction furnace for a period of time sufficient for compound decomposition. The decomposed compound is then heated in a microwave induction furnace in a reducing atmosphere for a period of time suf-ficient to reduce the decomposed compound to uranium dioxide powder, after which, the uranium dioxide powder is cooled 6~
in a reducing atmosphere. After cooling, the powder is available for use in a nuclear fuel preparation process.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure.
E`or a better understanding of the invention, i~s operating advantages and specific results obtained by its use, reference should be made to the descriptive mattex in which there is illustrated and described a typical embodi-ment of the invention.
DETAILED DESCRIPTION OF T~IE PP~EFERRED EMBODIMENT
A sinterable uranium dioxide powder to be used in anuclear fuel preparation process is produced by first selecting a commercially available starting material from the compound group of uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate. The selected start-ing material or compound is then heated in a microwave induc-tion furnace for a period of time sufficient to decompose the material, the composition of which may have a uranium oxide stoichiometric range of from UO3 to U3O8. The pre-ferred decomposition end product is U3O8 and the decompo-sition may be conducted in either an oxidizing, air, 2' or the like, mixed air-stream, or an inert atmosphere.
The decomposition step is conducted at a heating tempera-ture in the range of about 400 to 600C when uranyl nit-rate hexahydrate is selected as the starting compound.
The decomposition heating temperature is conducted in the ranye of about 350 to 450C when either ammonium diuranate or ammonium uranyl carbonate is selected as the starting compound. The decomposed compound is then heated in a microwave induction furnace in a reducing atmosphere con-sisting essentially of a hydrogen-nitrogen gas mix~ure, or the like, for a period of time sufficient to reduce the decomposed compound to uranium dioxide powder; the 6~
reduction step is conducted at a heating temperature in the range of about 450 to 550C notwithstanding -the start-ing material selected from the aforementioned compound group. The uranium dioxide powder i5 then cooled in a reducing atmosphere to approximately room temperature.
After cooling the powder is read~ for use in a muclear fuel preparation process.
Uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate were each subjected to microwave radiation in a microwave induction furnace at approximately 2450 MHz, the frequency of the standard kitchen-type micro-~ave oven, to determine the susceptance of each compound to microwave radiation. It should be understood thak, while a conventional microwave oven was selected for use because of its ready availability, other microwave induc tion fuxnaces operating at different frequencies would also be operable. Additionally, one oven or a plurality of ovens could be used for the decomposition and reduction processes. Each uranium compound readily suscepted, heat-ing rapidly. Other materials, however, such as niobia,alumina, silica, and graphite, when exposed to microwave radiation, while suscepting, did not exhibit the rapid heating found to be characteristic of the above compounds of uranium.
Uranyl nitrate hexahydrate crystals suscepted to microwave radiation in a microwave induction furnace in an oxidizing atmosphere by first forming a liquid as the hydrated water molecules were released, then decomposing in a 400 to 600C temperature range, progressively drying, releasing nitrous oxide gas and water ~apor and forming uranium trioxide (UO3). The UO3 was then heated to a temperature in the 450 to 500C range in a microwave induction furnace in a reducing atmosphere wherein water vapor was released and the UO3 was reduced to uranium di-oxide powder which was then cooled in the reducing 70~
atmosphere to about room temperature.
Ammonium diuranate, available as a filter cake,suscepted to microwave radiation in a microwave induction furnace in an oxidizing atmosphere by first releasing water and drying in the microwave field and then by de-composing in a 350 to 450~C temperature range, releasing ammonia gas and water vapor and forming U3O8. The U3O8 was then heated to a temperature in the 450 to 550C
range in a microwave induction furnace in a reducing atmosphere wherein water vapor was released and the U3O8 was reduced to uranium dioxide powder which was then cooled in the reducing atmosphere to about room teperature.
Ammonium uranyl carbonate, subjected to the condi-tions imposed upon ammonium diuranate, decomposed in much the same manner as did the ammonium diuranate, releasing gases of ammonia and water vapor with the additional release of carbon dioxide gas and forming U3O8. The reduc-tion of U3O8 to uranium dioxide powder, followed by cooling, proceeded as did the reduction and cooling of ammonium di-uranate.
Uranyl nitrate hexahydrate, ammonium diuranate andammonium uranyl carbonate decomposition and reduc-tion in a microwave induction furnace or furnaces is accomplished in processing times on the order of minutes rather than the hours customarily associated with the use of conven-tional electrical resistance furnacesO Additionally, the processing of a glossy or gelatinous filter cake does not hinder the microwave decomposition-reduction processes, the presence of such cakes lengthen process times in conventional furnaces and effect finished product ~uality.
Uranyl nitrate he~ahydrate, ammonium diuranate and ammoni-um uranyl carbonate processes in a microwave field produce a finished product o~ sinterable uranium dioxide powder suitable for use in a nuclear fuel preparation process.
~9~
While in accordance with the provisions of the statutes there is herein illustrated and described a specific embodiment of the invention, those skilled in the art will understand that changes may be made in the form of the invention covered by the claims, and that certain features of the invention may sometimes be used to advantage without corresponding use of the other features.
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An improved method for preparing a sinterable uranium dioxide powder for use in nuclear fuel preparation comprising the steps of:
selecting a starting material comprising a compound selected from the group consisting of uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate;
heating the starting compound in a microwave induction furnace for a period of time sufficient to decompose said starting compound, thereby yielding a decomposed compound in the range of from UO3 to U3O8;
heating the decomposed compound at a temperature range of about 450 to 550°C. in a microwave induction furnace in a reducing atmosphere for a period of time sufficient to reduce the decomposed compound to uranium dioxide powder; and cooling the uranium dioxide powder to about room temperature in a reducing atmosphere.
selecting a starting material comprising a compound selected from the group consisting of uranyl nitrate hexahydrate, ammonium diuranate and ammonium uranyl carbonate;
heating the starting compound in a microwave induction furnace for a period of time sufficient to decompose said starting compound, thereby yielding a decomposed compound in the range of from UO3 to U3O8;
heating the decomposed compound at a temperature range of about 450 to 550°C. in a microwave induction furnace in a reducing atmosphere for a period of time sufficient to reduce the decomposed compound to uranium dioxide powder; and cooling the uranium dioxide powder to about room temperature in a reducing atmosphere.
2. The method according to claim 1 wherein the first named heating is conducted in an oxidizing atmosphere.
3. The method according to claim 1 wherein the first named heating is conducted in a mixed air-steam atmosphere.
4. The method according to claim 1 wherein the first named heating is conducted in an inert atmosphere.
5. The method according to claim 1 wherein the starting material is uranyl nitrate hexahydrate and wherein the first named heating is conducted at a temperature in the range of about 400 to 600°C.
6. The method according to claim 1 wherein the starting material comprises a compound selected from the group consisting of ammonium diuranate and ammonium uranyl carbonate, and wherein the first named heating is conducted at a temperature in the range of about 350 to 450°C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US30126781A | 1981-09-11 | 1981-09-11 | |
| US06/301,267 | 1981-09-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1197069A true CA1197069A (en) | 1985-11-26 |
Family
ID=23162649
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000411251A Expired CA1197069A (en) | 1981-09-11 | 1982-09-10 | Method for preparing a sinterable uranium dioxide powder |
Country Status (18)
| Country | Link |
|---|---|
| JP (1) | JPS5874526A (en) |
| KR (1) | KR880002699B1 (en) |
| AT (1) | AT385267B (en) |
| AU (1) | AU8813382A (en) |
| BE (1) | BE894371A (en) |
| BR (1) | BR8205375A (en) |
| CA (1) | CA1197069A (en) |
| CH (1) | CH654820A5 (en) |
| DE (1) | DE3232867A1 (en) |
| DK (1) | DK406882A (en) |
| ES (1) | ES515439A0 (en) |
| FR (1) | FR2512801B1 (en) |
| GB (1) | GB2105697B (en) |
| IL (1) | IL66706A (en) |
| IT (2) | IT1192507B (en) |
| NL (1) | NL8203357A (en) |
| NO (1) | NO823079L (en) |
| SE (1) | SE8205138L (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6228337B1 (en) | 1998-12-02 | 2001-05-08 | Cameco Corporation | Method for reducing uranium trioxide |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7824640B1 (en) | 2006-07-25 | 2010-11-02 | Westinghouse Electric Co. Llc | Two step dry UO2 production process utilizing a positive sealing valve means between steps |
| EP1985587A1 (en) * | 2007-04-27 | 2008-10-29 | Westinghouse Electric Company LLC | Two step dry UO2 production process |
| CN113023782B (en) * | 2021-03-10 | 2023-05-05 | 哈尔滨工程大学 | Sodium diuranate (Na) 2 U 2 O 7 ) Direct preparation of UO 2 Is a method of (2) |
| CN116253363A (en) * | 2022-11-25 | 2023-06-13 | 中国核动力研究设计院 | Uranium dioxide powder and preparation method and application thereof |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3579311A (en) * | 1968-04-25 | 1971-05-18 | Gen Electric | Process and apparatus for producing uo2 powder |
| FR2370695A1 (en) * | 1976-11-16 | 1978-06-09 | Comurhex | Uranium oxide prodn. by thermal decomposition of uranyl nitrate - with catalytic reduction of the nitrogen oxide(s) produced to provide heat for the process |
| DE2724710A1 (en) * | 1977-06-01 | 1978-12-07 | Reaktor Brennelement Union | Uranium di:oxide powder prodn. - by reducing ammonium uranyl carbonate with ammonia in steam, giving low fluoride content |
| JPS54121442A (en) * | 1978-03-13 | 1979-09-20 | Power Reactor & Nuclear Fuel Dev Corp | Microwave heating device for radioactive material |
| JPS55104926A (en) * | 1979-01-29 | 1980-08-11 | Toshiba Corp | Microwave heat-denitrating apparatus |
-
1982
- 1982-08-27 NL NL8203357A patent/NL8203357A/en not_active Application Discontinuation
- 1982-09-02 IL IL66706A patent/IL66706A/en unknown
- 1982-09-02 ES ES515439A patent/ES515439A0/en active Granted
- 1982-09-03 GB GB08225109A patent/GB2105697B/en not_active Expired
- 1982-09-03 DE DE19823232867 patent/DE3232867A1/en not_active Withdrawn
- 1982-09-06 JP JP57154070A patent/JPS5874526A/en active Pending
- 1982-09-06 CH CH5292/82A patent/CH654820A5/en not_active IP Right Cessation
- 1982-09-08 AT AT0335682A patent/AT385267B/en not_active IP Right Cessation
- 1982-09-08 AU AU88133/82A patent/AU8813382A/en not_active Abandoned
- 1982-09-09 SE SE8205138A patent/SE8205138L/en not_active Application Discontinuation
- 1982-09-10 NO NO823079A patent/NO823079L/en unknown
- 1982-09-10 DK DK406882A patent/DK406882A/en not_active Application Discontinuation
- 1982-09-10 KR KR8204119A patent/KR880002699B1/en active
- 1982-09-10 BE BE0/208992A patent/BE894371A/en not_active IP Right Cessation
- 1982-09-10 IT IT09510/82A patent/IT1192507B/en active
- 1982-09-10 FR FR828215362A patent/FR2512801B1/en not_active Expired
- 1982-09-10 IT IT1982A09510A patent/IT8209510A1/en unknown
- 1982-09-10 CA CA000411251A patent/CA1197069A/en not_active Expired
- 1982-09-13 BR BR8205375A patent/BR8205375A/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6228337B1 (en) | 1998-12-02 | 2001-05-08 | Cameco Corporation | Method for reducing uranium trioxide |
| US7029633B2 (en) | 1998-12-02 | 2006-04-18 | Cameco Corporation | Method and apparatus for reducing uranium trioxide |
Also Published As
| Publication number | Publication date |
|---|---|
| ES8403347A1 (en) | 1984-04-01 |
| NO823079L (en) | 1983-03-14 |
| KR880002699B1 (en) | 1988-12-26 |
| CH654820A5 (en) | 1986-03-14 |
| JPS5874526A (en) | 1983-05-06 |
| FR2512801B1 (en) | 1989-02-24 |
| IT8209510A0 (en) | 1982-09-10 |
| IL66706A0 (en) | 1982-12-31 |
| GB2105697B (en) | 1985-09-11 |
| SE8205138D0 (en) | 1982-09-09 |
| IL66706A (en) | 1986-01-31 |
| ES515439A0 (en) | 1984-04-01 |
| NL8203357A (en) | 1983-04-05 |
| IT8209510A1 (en) | 1984-03-10 |
| IT1192507B (en) | 1988-04-20 |
| KR840001452A (en) | 1984-05-07 |
| ATA335682A (en) | 1987-08-15 |
| SE8205138L (en) | 1983-03-12 |
| AT385267B (en) | 1988-03-10 |
| BR8205375A (en) | 1983-08-23 |
| BE894371A (en) | 1983-01-03 |
| GB2105697A (en) | 1983-03-30 |
| FR2512801A1 (en) | 1983-03-18 |
| DK406882A (en) | 1983-03-12 |
| AU8813382A (en) | 1983-03-17 |
| DE3232867A1 (en) | 1983-12-15 |
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