GB2229172A - Producing UF6 - Google Patents
Producing UF6 Download PDFInfo
- Publication number
- GB2229172A GB2229172A GB9001748A GB9001748A GB2229172A GB 2229172 A GB2229172 A GB 2229172A GB 9001748 A GB9001748 A GB 9001748A GB 9001748 A GB9001748 A GB 9001748A GB 2229172 A GB2229172 A GB 2229172A
- Authority
- GB
- United Kingdom
- Prior art keywords
- reactor
- fluorine
- uranium
- recycled
- gaseous product
- 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.)
- Granted
Links
- 229910052731 fluorine Inorganic materials 0.000 claims abstract description 31
- 239000011737 fluorine Substances 0.000 claims abstract description 31
- 238000012544 monitoring process Methods 0.000 claims abstract description 7
- JCMLRUNDSXARRW-UHFFFAOYSA-N trioxouranium Chemical compound O=[U](=O)=O JCMLRUNDSXARRW-UHFFFAOYSA-N 0.000 claims description 61
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 29
- 239000007789 gas Substances 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 16
- SANRKQGLYCLAFE-UHFFFAOYSA-H uranium hexafluoride Chemical compound F[U](F)(F)(F)(F)F SANRKQGLYCLAFE-UHFFFAOYSA-H 0.000 claims description 12
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 claims description 6
- 229910001634 calcium fluoride Inorganic materials 0.000 claims description 6
- 239000011261 inert gas Substances 0.000 claims description 5
- 239000008187 granular material Substances 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 230000000295 complement effect Effects 0.000 claims description 2
- 238000001816 cooling Methods 0.000 claims description 2
- 238000000605 extraction Methods 0.000 claims 1
- BRPBSNYFMUTCHH-UHFFFAOYSA-H hexafluorouranium;uranium Chemical compound [U].F[U](F)(F)(F)(F)F BRPBSNYFMUTCHH-UHFFFAOYSA-H 0.000 claims 1
- 238000004064 recycling Methods 0.000 claims 1
- WZECUPJJEIXUKY-UHFFFAOYSA-N [O-2].[O-2].[O-2].[U+6] Chemical compound [O-2].[O-2].[O-2].[U+6] WZECUPJJEIXUKY-UHFFFAOYSA-N 0.000 abstract description 2
- 239000000446 fuel Substances 0.000 abstract description 2
- 238000000638 solvent extraction Methods 0.000 abstract description 2
- 229910000439 uranium oxide Inorganic materials 0.000 abstract description 2
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 abstract 2
- 239000000463 material Substances 0.000 abstract 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 239000003085 diluting agent Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- ZSLUVFAKFWKJRC-IGMARMGPSA-N 232Th Chemical compound [232Th] ZSLUVFAKFWKJRC-IGMARMGPSA-N 0.000 description 1
- 229910052778 Plutonium Inorganic materials 0.000 description 1
- 229910052776 Thorium Inorganic materials 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 230000001447 compensatory effect Effects 0.000 description 1
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 description 1
- 238000012958 reprocessing Methods 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G43/00—Compounds of uranium
- C01G43/04—Halides of uranium
- C01G43/06—Fluorides
- C01G43/063—Hexafluoride (UF6)
- C01G43/066—Preparation
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
The hexafluoride is produced from UO3 by contacting with F2 in a fluidising reactor. The temperature of the reactor is monitored, and the gaseous product from the reactor is monitored to detect fluorine therein. The rate of feed of UO3 into the reactor and the proportion of fluorine in the fluidising gas stream into the reactor is controlled in response to the temperature and F2 monitoring so as to maintain the UO3 in the reactor at 470 DEG C to 500 DEG C. UO3 source material is from solvent extraction of irradiated uranium oxide fuels.
Description
A process for producing uranium hexafluoride
This invention relates to the production of uranium hexafluoride from uranium trioxide, and more particularly from recycled uranium trioxide. As used herein "recycled uranium trioxide" means, uranium trioxide recovered from uranium oxide fuel previously irradiated and subsequently reprocessed by known solvent extraction techniques to separate inter-alia uranium impurities from the reprocessing cycle.
According to the present invention, there is provided a process for producing uranium hexafluoride from recycled uranium trioxide, the process comprising feeding recycled uranium trioxide into a fluidising reactor, contacting the recycled uranium trioxide with a fluidising gas stream comprising fluorine and an inert gas, monitoring the gaseous product from the reactor and the temperature of the reactor and controlling therefrom the rate of feed of the uranium trioxide into theveactor and the proportion of fluorine in the fluidising gas stream, so as to maintain the recycled uranium trioxide in the reactor within a predetermined temperature range.
Preferably, the temperature range is between 470"C and 500"C.
Desirably, the fluorine content of the gaseous product is monitored.
Advantageously, cooling means are disposed about the reactor.
Desirably, the fluidising gas stream is maintained at a constant flow rate, the proportion of the inert gas in the fluidising gas stream being varied in a complementary manner as the proportion of fluorine is varied.
Advantageously, calcium fluoride granules are fed intermittently into the reactor.
The reaction of recycled uranium trioxide with fluorine is highly exothermic and one result of such a reaction that has given major problems in the past is sintering of solids in the reactor leading to a reduced reaction rate and to difficulties in removal of the solids from the reactor. The invention by relating the rate of feed of the recycled uranium trioxide and the proportion of fluorine in the gas stream to the concentration of fluorine in the gaseous product from the reactor and to the temperature of the reactor, enables optimum conditions to be established in which sintering of solids is held to a minimum.
The invention will now be described by way of example only with reference to the flow sheet in the accompanying drawing, and to the Example.
Referring firstly to the flow sheet, a fluidising gas stream comprising fluorine from a known fluorine cell (not shown) with nitrogen as a diluent is passed through a fluidising reactor into which granular calcium fluoride is also fed intermittently into the reactor. Granular recycled uranium trioxide is fed at a controlled rate into the reactor where the recycled uranium trioxide reacts with the fluorine to form gaseous uranium hexafluoride, the chemical reactions taking place in the reactor being:
Heat produced from the exothermic chemical reaction is at the rate of 217 Kcal/mol U.
The gaseous product from the reactor is monitored to detect fluorine, and the temperature of the reactor is also monitored. The rate of feed of the recycled uranium trioxide into the reactor and the proportion of fluorine from the fluorine cell entering the fluidising gas stream is controlled as a function of the detected fluorine in the gaseous product and the temperature. This enables the temperature in the reactor to be controlled between the optimum range of 470"C to 500"C. Temperature excursions are therefore minimised. Initially when excess fluorine gas is detected in the gaseous product, the feed of the recycled uranium trioxide into the reactor is increased.If the temperature of the reactor rises to 500"C, the rate of feed of the recycled uranium trioxide is reduced and if necessary the proportion of the fluorine in the fluidising gas stream is reduced with a compensatory increase in the nitrogen content. The reduction of fluorine reduces the number of chemical reactions taking place in the reactor, and the increased nitrogen content assists heat transfer from the reactor.
The calcium fluoride granules assist in heat transfer distribution in the reactor, and also retain impurities in the original recycled uranium trioxide, eg plutonium and thorium.
The feed of uranium trioxide to the reactor can be by a conventional screw conveyor and a rotary valve, the rotary valve dispensing the uranium trioxide into the screw conveyor. A suitable rotary valve may be obtained from Mucon, Basingstoke, RG22 4AA, United Kingdom. The screw conveyor may include stages thereof arranged to dispense from one stage to the other.
The gaseous product after removal of the uranium hexafluoride and some of the tail gases can be recycled through the reactor to avoid waste of the fluorine in the gaseous product.
EXAMPLE
182 kilograms/hour of recycled U03 was fed into a fluidised bed reactor with a feed of 3'kg/hr of CaF2. A fluidising gas stream comprising 87 kg/hr F2 with 2.5 kg/hr N2 as a diluent was passed through the reactor to react with the recycled U03. The gaseous product from the reactor was condensed to extract the UF6 product (k225 kg/hr). The remaining gases were compressed and recycled. The concentration of the fluorine gas in the gaseous product-and the temperature of the reactor were monitored, and the signals generated by the monitors were used to control both the feed of the recycled U03 into the reactor and the proportion of the fluorine in the gas stream. It was found that a concentration between 5-10% by volume of fluorine in the gaseous product indicated that conditions inside the reactor were optimum within optimum temperatures of 470"C to 500"C.
Claims (16)
1. A process for producing uranium hexafluoride from recycled uranium trioxide, the process comprising feeding recycled uranium trioxide into a fluidising reactor, contacting the recycled uranium trioxide with a fluidising gas stream comprising fluorine and an inert gas, monitoring the gaseous product from the reactor and the temperature of the reactor and controlling therefrom the rate of feed of the uranium trioxide into the reactor and the proportion of fluorine in the fluidising gas stream, so as to maintain the recycled uranium trioxide in the reactor within a predetermined temperature range.
2. A process as claimed in Claim 1, wherein the temperature range is between 470"C and 500"C.
3. A process as claimed in Claim 2, wherein cooling means are disposed about the reactor to assist in maintaining the reactor within the temperature range.
4. A process as claimed in any one of Claims 1 tq 3, wherein the fluorine content of the gaseous product is monitored.
5. A process as claimed in any one of the preceding
Claims wherein the fluidising gas stream is maintained at a constant flow rate, the proportion of the inert gas in the fluidising gas stream being varied in a complementary manner as the proportion of fluorine is varied.
6. A process as claimed in any one of the preceding
Claims, wherein granules comprising calcium fluoride are fed intermittently into the reactor.
7. A process as claimed in any one of the preceding
Claims, wherein the proportion of fluorine in the fluidising gas stream is controlled so that it is between 5 to 10% by volume of the gaseous product.
8. A process as claimed in any one of the preceding
Claims, wherein the gaseous product is condensed to extract the uranium uranium hexafluoride therein and subsequently compressed and recycled.
9. Apparatus for performing the process of Claim 1 and comprising, a fluidising reactor, means for feeding recycled uranium trioxide into the reactor, means for feeding a fluidising gas stream into the reactor, said fluidising gas stream comprising fluorine and an inert gas, means for monitoring the temperature of the reactor, means for monitoring fluorine in a gaseous product from the reactor, and means for controlling the rate of feed of the recycled uranium trioxide and the proportion of fluorine in the fluidising gas stream in response to signals from the temperature monitoring means and the gaseous product monitoring means, so that the recycled uranium trioxide is maintained within a predetermined temperature range in the reactor.
10. Apparatus as claimed in Claim 9, wherein the means for feeding the recycled uranium trioxide comprises a rotary valve arranged to dispense said recycled uranium trioxide into screw conveyor means.
11. Apparatus as claimed in Claim 9 or Claim 10, including means for condensing gaseous product from the reactor to extract uranium hexafluoride therefrom.
12. Apparatus as claimed in Claim 11, including means for compressing the gaseous product after said extraction of the uranium hexafluoride, and means for recycling the compressed gaseous product to the reactor.
13. Apparatus as claimed in any one of Claims 9 to 12, including means for feeding granules comprising calcium fluoride into the reactor.
14. A process for the production of uranium hexafluoride substantially as hereinbefore described with reference to the flow sheet in the accompanying drawing and/or to the
Example.
15. Uranium hexafluoride made by the process as claimed in any one of Claims 1 to 8, or Claim 14.
16. Apparatus for the production of uranium hexafluoride substantially as hereinbefore described with reference to the accompanying flow sheet.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB898906004A GB8906004D0 (en) | 1989-03-15 | 1989-03-15 | A process for producing uranium hexafluoride |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9001748D0 GB9001748D0 (en) | 1990-03-28 |
| GB2229172A true GB2229172A (en) | 1990-09-19 |
| GB2229172B GB2229172B (en) | 1992-07-22 |
Family
ID=10653411
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB898906004A Pending GB8906004D0 (en) | 1989-03-15 | 1989-03-15 | A process for producing uranium hexafluoride |
| GB9001748A Expired - Lifetime GB2229172B (en) | 1989-03-15 | 1990-01-25 | A process for producing uranium hexafluoride |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB898906004A Pending GB8906004D0 (en) | 1989-03-15 | 1989-03-15 | A process for producing uranium hexafluoride |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP2960943B2 (en) |
| FR (1) | FR2644447B1 (en) |
| GB (2) | GB8906004D0 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993003997A1 (en) * | 1991-08-13 | 1993-03-04 | Cameco Corporation | Generation of fluorine via thermal plasma decomposition of metal fluoride |
| US10037823B2 (en) | 2010-05-11 | 2018-07-31 | Thorium Power, Inc. | Fuel assembly |
| US10170207B2 (en) | 2013-05-10 | 2019-01-01 | Thorium Power, Inc. | Fuel assembly |
| US10192644B2 (en) | 2010-05-11 | 2019-01-29 | Lightbridge Corporation | Fuel assembly |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8116423B2 (en) | 2007-12-26 | 2012-02-14 | Thorium Power, Inc. | Nuclear reactor (alternatives), fuel assembly of seed-blanket subassemblies for nuclear reactor (alternatives), and fuel element for fuel assembly |
| KR101474864B1 (en) | 2007-12-26 | 2014-12-19 | 토륨 파워 인코포레이티드 | Nuclear reactor(variants), fuel assembly consisting of driver-breeding modules for a nuclear reactor(variants) and a fuel cell for a fuel assembly |
| EP2372717B1 (en) | 2008-12-25 | 2016-04-13 | Thorium Power, Inc. | Fuel assembly for a light-water nuclear reactor and light-water nuclear reactor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4704261A (en) * | 1955-01-17 | 1987-11-03 | The United States Of America As Represented By The United States Department Of Energy | Method for fluorination of uranium oxide |
-
1989
- 1989-03-15 GB GB898906004A patent/GB8906004D0/en active Pending
-
1990
- 1990-01-25 GB GB9001748A patent/GB2229172B/en not_active Expired - Lifetime
- 1990-03-12 FR FR9003100A patent/FR2644447B1/en not_active Expired - Lifetime
- 1990-03-15 JP JP2065512A patent/JP2960943B2/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993003997A1 (en) * | 1991-08-13 | 1993-03-04 | Cameco Corporation | Generation of fluorine via thermal plasma decomposition of metal fluoride |
| US5207999A (en) * | 1991-08-13 | 1993-05-04 | Cameco Corporation | Generation of fluorine via thermal plasma decomposition of metal fluoride |
| US10037823B2 (en) | 2010-05-11 | 2018-07-31 | Thorium Power, Inc. | Fuel assembly |
| US10192644B2 (en) | 2010-05-11 | 2019-01-29 | Lightbridge Corporation | Fuel assembly |
| US10991473B2 (en) | 2010-05-11 | 2021-04-27 | Thorium Power, Inc. | Method of manufacturing a nuclear fuel assembly |
| US11195629B2 (en) | 2010-05-11 | 2021-12-07 | Thorium Power, Inc. | Fuel assembly |
| US11837371B2 (en) | 2010-05-11 | 2023-12-05 | Thorium Power, Inc. | Method of manufacturing a nuclear fuel assembly |
| US11862353B2 (en) | 2010-05-11 | 2024-01-02 | Thorium Power, Inc. | Fuel assembly |
| US10170207B2 (en) | 2013-05-10 | 2019-01-01 | Thorium Power, Inc. | Fuel assembly |
| US11211174B2 (en) | 2013-05-10 | 2021-12-28 | Thorium Power, Inc. | Fuel assembly |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2229172B (en) | 1992-07-22 |
| FR2644447B1 (en) | 1992-07-24 |
| FR2644447A1 (en) | 1990-09-21 |
| GB9001748D0 (en) | 1990-03-28 |
| JPH02283620A (en) | 1990-11-21 |
| GB8906004D0 (en) | 1989-04-26 |
| JP2960943B2 (en) | 1999-10-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20090125 |