CA1078327A - Method for isotope enrichment - Google Patents
Method for isotope enrichmentInfo
- Publication number
- CA1078327A CA1078327A CA252,896A CA252896A CA1078327A CA 1078327 A CA1078327 A CA 1078327A CA 252896 A CA252896 A CA 252896A CA 1078327 A CA1078327 A CA 1078327A
- Authority
- CA
- Canada
- Prior art keywords
- isotope
- compounds
- reactant
- mixture
- reaction zone
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D59/00—Separation of different isotopes of the same chemical element
- B01D59/34—Separation by photochemical methods
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/08—Construction or shape of optical resonators or components thereof
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Life Sciences & Earth Sciences (AREA)
- Biophysics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Optics & Photonics (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Abstract of the Disclosure Method for isotope enrichment, particularly uranium compounds, by passing the mixture of isotope compounds and a reaction partner consisting of atomic gas or radical in concurrent flow through a reaction zone, selectively exciting an isotope compound by means of laser radiation, chemically reacting the excited compound with the reaction partner, regu-lating the flow of reactants to produce reaction products substantially free of atomic gas or radical at discharge from reaction zone. Reduces undesired side reactions and unwanted by-products and facilitates separation of enriched isotope.
Description
10783~7 This invention relates to a method for isotope enrichment, and more particularly refers to a new and improved process for isotope en-richment of uranium compounds by selectively exciting an isotope compound by means of laser radiation and chemically reacting the excited compound with a reaction partner.
The separation of isotopes, specifically uranium isGtopes, via selective excitation of molecules followed by a chemical reaction with a reaction partner, is known per se and can be carried out most simply in the gaseous phase (see, for instance the German Published Non-Prosecuted Application DT-OS 1 959 767). Unfortunately, even if it were possible to selectively excite by a suitably laser frequency only that isotope compound which is to be separated or enriched, the separation effect is substantially diminished by the competing thermal reactions and the transfer of the excitation energy between excited and non-excited molecules.
An object of the invention is to provide a method for process of isotope enrichment in which the phenomena of competing reactions and transfer of excitation energy are largely eliminated, so that the separation effect depends substantially on the selectivity of the excitation process itself.
With the foregoing and other objects in view there is provided in accordance with the invention, a method for the enrichment of isotopes from a mixture of respective compounds containing the respective isotopes by means of laser radiation to selectively excite an isotope compound and chemically react the excited isotope compound with a reactant, which includes passing a mixture of isotope compounds through a reaction zone, passing a reactant selected from group consisting of atomic gas and radical in contact with and in concurrent flow with the mixture of isotope compounds through the reaction zone, subjecting the mixture of isotope compounds and ,~
`` 1~783~7 the reactant during the concurrent flow through the reaction zone to laser radiation to selectively excite an isotope compound and chemically react the excited compound with the reactant, regulating the flow of the mixture of isotopes and the reactant in the reaction zone to effect substantially complete consumption of the reactant during its flow through the reaction zone, and discharging reaction products substantially free of the reactant from the reaction zone.
In accordance with the invention, atomic gases or radicals are used as the reaction partner which, together with the starting compounds, flow through the reaction chamber so fast that recombination of the reaction partner takes place by the time they leave the reaction chamber. Conducting the process in this manner has the advantage that the desired reaction takes place very rapidly and thus, a decrease in the selectivity of the separation process is largely prevented, normally due to a competing thermal reaction and energy transfer from excited 35U molecules to nonexcited 3 U molecules. A further advantage is the rapid recombination of the reaction partner or reactant, which precludes an undesired further reaction of the process gases outside the reaction chamber and thereby simplifies the further separation and processing of the depleted and enriched uranium fractions.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as ~-embodied in method for isotope enrichment, it is nevertheless not intended to be limited to the details shown, since various modifications may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The invention, however, together with additional objects and advantages thereof will be best understood from the following description when read in connection with the accompanying drawing.
The accompanying drawing diagrammatically illustrates apparatus for utilizing the method in accordance with the invention for isotope enrichment.
The apparatus shown schematically in the drawing is suitable for carrying the method of the present invention. The reaction chamber 1 consists of a tube which is closed off on both sides by Brewster windows
The separation of isotopes, specifically uranium isGtopes, via selective excitation of molecules followed by a chemical reaction with a reaction partner, is known per se and can be carried out most simply in the gaseous phase (see, for instance the German Published Non-Prosecuted Application DT-OS 1 959 767). Unfortunately, even if it were possible to selectively excite by a suitably laser frequency only that isotope compound which is to be separated or enriched, the separation effect is substantially diminished by the competing thermal reactions and the transfer of the excitation energy between excited and non-excited molecules.
An object of the invention is to provide a method for process of isotope enrichment in which the phenomena of competing reactions and transfer of excitation energy are largely eliminated, so that the separation effect depends substantially on the selectivity of the excitation process itself.
With the foregoing and other objects in view there is provided in accordance with the invention, a method for the enrichment of isotopes from a mixture of respective compounds containing the respective isotopes by means of laser radiation to selectively excite an isotope compound and chemically react the excited isotope compound with a reactant, which includes passing a mixture of isotope compounds through a reaction zone, passing a reactant selected from group consisting of atomic gas and radical in contact with and in concurrent flow with the mixture of isotope compounds through the reaction zone, subjecting the mixture of isotope compounds and ,~
`` 1~783~7 the reactant during the concurrent flow through the reaction zone to laser radiation to selectively excite an isotope compound and chemically react the excited compound with the reactant, regulating the flow of the mixture of isotopes and the reactant in the reaction zone to effect substantially complete consumption of the reactant during its flow through the reaction zone, and discharging reaction products substantially free of the reactant from the reaction zone.
In accordance with the invention, atomic gases or radicals are used as the reaction partner which, together with the starting compounds, flow through the reaction chamber so fast that recombination of the reaction partner takes place by the time they leave the reaction chamber. Conducting the process in this manner has the advantage that the desired reaction takes place very rapidly and thus, a decrease in the selectivity of the separation process is largely prevented, normally due to a competing thermal reaction and energy transfer from excited 35U molecules to nonexcited 3 U molecules. A further advantage is the rapid recombination of the reaction partner or reactant, which precludes an undesired further reaction of the process gases outside the reaction chamber and thereby simplifies the further separation and processing of the depleted and enriched uranium fractions.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as ~-embodied in method for isotope enrichment, it is nevertheless not intended to be limited to the details shown, since various modifications may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The invention, however, together with additional objects and advantages thereof will be best understood from the following description when read in connection with the accompanying drawing.
The accompanying drawing diagrammatically illustrates apparatus for utilizing the method in accordance with the invention for isotope enrichment.
The apparatus shown schematically in the drawing is suitable for carrying the method of the present invention. The reaction chamber 1 consists of a tube which is closed off on both sides by Brewster windows
2. Laser radiation 6, which is further amplified by means of resonator mirrors 7 and 8, passes through this vessel in the axial direction. The -isotope mixture to be separated enters the reaction chamber 1 via the line
3, and the reaction partner via the line 4. The reaction product as well ~ ;
as unreacted gases are discharged via the line 5. Nitrogen gas, for example, can be blown via the line 10 against the Brewster window 2, to prevent solid reaction products depositing thereon. Flushing gas is advantageously used and may be the gas which is supplied as the reaction partner via the line 4. Inside the reaction chamber, there is provided a source 9, for example, of ultraviolet radiation to produce the atomic state of the reaction partner supplied via the line 4.
Although the method can be used for separation or enrichment of isotopes other than uranium, this method is preferably intended for the separation of uranium isotopes. The method and apparatus in accordance with the invention are described for the separation of uranium isotopes with reference to the use of uranium Hexfluoride UF6 as the starting isotope mixture.
Hydrogen, oxygen or nitrogen in atomic form are suitable as the reaction partner. The atomic hydrogen is generated most simply by ultra-violet irradiation by means o~ the burner 9 shown in the drawing, but electric discharge gap would also be suitable for this purpose. The fol-lowing exothermic reactions then proceed in the reaction chamber 1:
. .
` 1078327 UF6 + H > UF5 + HF - 54.5 kcal and UF5 + H ~ > 4 - 42.2 kcal The pressure in the reaction chamber is, for example, about 0.01 Torr and the half-life for the recombination of the atomic hydrogen is then about 0.3 sec. The length of the reaction chamber and the flow vel-ocity of the reaction mixture are set in accordance with this time. In order to make sure that no atomic hydrogen still gets into the output line 5 and no undesired reactions take place there, a catalyst, e.g., platinum screen, can be arranged at the entranced line 5 to accelerate the recombin-ation. No other additional reaction steps are necessary for the further processing of the enriched or depleted uranium fractions, as the initially gaseous substances UF5 and UF4 are condensed to solid substances and can be separated easily from the rest of the reaetion mixture in this manner.
Atomic nitrogen can also be used as a reaction partner, which can be generated, for example, by a high-f~equency ring diseharge in the reaction chamber 1 (in place of the ultraviolet radiator 9). The reaction between UF6 and atomic nitrogen proceeds in accordance with the following equation:
3 UF6 + N > 3 UF5 + NF3 .
Solid UF5 and the gaseous nitrogen fluoride NF3 are produced.
Further processing therefore presents no difficulties here either.
Atomic oxygen, too, is suitable as a reaction partner; it can likewise be generated by ultraviolet radiation or by a corona discharge.
The following equation then applies to the reaction of the oxygen with the UF6:
6 2 UF5 + 2 F2 Here, too, solid UF5 and gaseous difluoro oxide are produced.
Radicals such as, for example, CH3~ (methyl) have a similar 107832~
reactive effect as these atomic gases. CH3~ is formedJ for example, from azomethane at 60 to 100 C- As CH3~ has a very short life, it is advisable to have it likewise formed in the reaction chamber 1. For this purpose, the azomethane is fed-in via the line 4 and a suitable infrared radiator is arranged in the place of the ultraviolet burner 9; possible also outside the walls of the vessel. As nitrogen is produced in the formation of the methyl, it is advantageous to use nitrogen also as the flushing gas for the Brewster window 2.
The following reaction then occurs in the reaction chamber:
CH3 - N = C~l 3 2 r 6 3 ~ UF5 + CH3 F
Here, too, the separation of the solid reaction product UF5 from the gaseous methylfluoride CH3F presents no difficulties.
As a further example, the use of the aldehyde group as the radical (CH~) will be mentioned. This can be formed from an aldehyde as in the previous example, directly in the reaction chamber 1 by means of ultra-violet light. RCH0 is fed-in via the line 4, R representing, for example, hydrogen or the aIkyl radical.
These exampl~ show how to achieve high selectivity of the laser-induced chemical reactions with short-life, but highly reactive substances.
as unreacted gases are discharged via the line 5. Nitrogen gas, for example, can be blown via the line 10 against the Brewster window 2, to prevent solid reaction products depositing thereon. Flushing gas is advantageously used and may be the gas which is supplied as the reaction partner via the line 4. Inside the reaction chamber, there is provided a source 9, for example, of ultraviolet radiation to produce the atomic state of the reaction partner supplied via the line 4.
Although the method can be used for separation or enrichment of isotopes other than uranium, this method is preferably intended for the separation of uranium isotopes. The method and apparatus in accordance with the invention are described for the separation of uranium isotopes with reference to the use of uranium Hexfluoride UF6 as the starting isotope mixture.
Hydrogen, oxygen or nitrogen in atomic form are suitable as the reaction partner. The atomic hydrogen is generated most simply by ultra-violet irradiation by means o~ the burner 9 shown in the drawing, but electric discharge gap would also be suitable for this purpose. The fol-lowing exothermic reactions then proceed in the reaction chamber 1:
. .
` 1078327 UF6 + H > UF5 + HF - 54.5 kcal and UF5 + H ~ > 4 - 42.2 kcal The pressure in the reaction chamber is, for example, about 0.01 Torr and the half-life for the recombination of the atomic hydrogen is then about 0.3 sec. The length of the reaction chamber and the flow vel-ocity of the reaction mixture are set in accordance with this time. In order to make sure that no atomic hydrogen still gets into the output line 5 and no undesired reactions take place there, a catalyst, e.g., platinum screen, can be arranged at the entranced line 5 to accelerate the recombin-ation. No other additional reaction steps are necessary for the further processing of the enriched or depleted uranium fractions, as the initially gaseous substances UF5 and UF4 are condensed to solid substances and can be separated easily from the rest of the reaetion mixture in this manner.
Atomic nitrogen can also be used as a reaction partner, which can be generated, for example, by a high-f~equency ring diseharge in the reaction chamber 1 (in place of the ultraviolet radiator 9). The reaction between UF6 and atomic nitrogen proceeds in accordance with the following equation:
3 UF6 + N > 3 UF5 + NF3 .
Solid UF5 and the gaseous nitrogen fluoride NF3 are produced.
Further processing therefore presents no difficulties here either.
Atomic oxygen, too, is suitable as a reaction partner; it can likewise be generated by ultraviolet radiation or by a corona discharge.
The following equation then applies to the reaction of the oxygen with the UF6:
6 2 UF5 + 2 F2 Here, too, solid UF5 and gaseous difluoro oxide are produced.
Radicals such as, for example, CH3~ (methyl) have a similar 107832~
reactive effect as these atomic gases. CH3~ is formedJ for example, from azomethane at 60 to 100 C- As CH3~ has a very short life, it is advisable to have it likewise formed in the reaction chamber 1. For this purpose, the azomethane is fed-in via the line 4 and a suitable infrared radiator is arranged in the place of the ultraviolet burner 9; possible also outside the walls of the vessel. As nitrogen is produced in the formation of the methyl, it is advantageous to use nitrogen also as the flushing gas for the Brewster window 2.
The following reaction then occurs in the reaction chamber:
CH3 - N = C~l 3 2 r 6 3 ~ UF5 + CH3 F
Here, too, the separation of the solid reaction product UF5 from the gaseous methylfluoride CH3F presents no difficulties.
As a further example, the use of the aldehyde group as the radical (CH~) will be mentioned. This can be formed from an aldehyde as in the previous example, directly in the reaction chamber 1 by means of ultra-violet light. RCH0 is fed-in via the line 4, R representing, for example, hydrogen or the aIkyl radical.
These exampl~ show how to achieve high selectivity of the laser-induced chemical reactions with short-life, but highly reactive substances.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a method for the enrichment of isotopes from a mixture of respective compounds containing the respective isotopes by means of laser radiation to selectively excite an isotope compound and chemically react the excited isotope compound with a reactant, the improvement which comp-rises passing a mixture of isoptope compounds through a reaction zone, passing a reactant selected from the group consisting of atomic gas and radical in contact with and in concurrent flow with said mixture of isotope compounds through said reaction zone, subjecting said mixture of isotope compounds and said reactant during said concurrent flow through said reaction zone to laser radiation to selectively excite an isotope compound and che-mically react said excited compound with said reactant, regulating the flow of said mixture of isotopes and said reactant in said reaction zone to effect substantially complete comsumption of said reactant during its flow through the reaction zone, and discharging reaction products substantially free of said reactant from said reaction zone.
2. Method according to claim 1 wherein said mixture of isotope compounds is gaseous UF6 compounds, and said UF6 compounds are subjected to continuous laser radiation having a frequency to selectively excite the uranium isotope compound U235F6 in said mixture of UF6 compounds.
3. Method according to claim 1 wherein said reactant is selected from the group consisting of atomic hydrogen, oxygen, nitrogen and methyl radical CH3 and aldehyde radical CHO.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2524127A DE2524127C3 (en) | 1975-05-30 | 1975-05-30 | Process for isotope separation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1078327A true CA1078327A (en) | 1980-05-27 |
Family
ID=5947870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA252,896A Expired CA1078327A (en) | 1975-05-30 | 1976-05-19 | Method for isotope enrichment |
Country Status (7)
| Country | Link |
|---|---|
| AU (1) | AU501271B2 (en) |
| CA (1) | CA1078327A (en) |
| DE (1) | DE2524127C3 (en) |
| FR (1) | FR2312284A1 (en) |
| GB (1) | GB1517436A (en) |
| IL (1) | IL49636A (en) |
| ZA (1) | ZA763162B (en) |
-
1975
- 1975-05-30 DE DE2524127A patent/DE2524127C3/en not_active Expired
-
1976
- 1976-05-19 CA CA252,896A patent/CA1078327A/en not_active Expired
- 1976-05-24 IL IL49636A patent/IL49636A/en unknown
- 1976-05-24 AU AU14233/76A patent/AU501271B2/en not_active Expired
- 1976-05-26 FR FR7616111A patent/FR2312284A1/en not_active Withdrawn
- 1976-05-26 ZA ZA763162A patent/ZA763162B/en unknown
- 1976-05-27 GB GB22178/76A patent/GB1517436A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2524127A1 (en) | 1976-12-02 |
| IL49636A (en) | 1978-12-17 |
| DE2524127C3 (en) | 1980-09-11 |
| ZA763162B (en) | 1977-05-25 |
| AU1423376A (en) | 1977-12-01 |
| AU501271B2 (en) | 1979-06-14 |
| DE2524127B2 (en) | 1980-01-17 |
| GB1517436A (en) | 1978-07-12 |
| IL49636A0 (en) | 1976-07-30 |
| FR2312284A1 (en) | 1976-12-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |