CA1203773A - Isotopic separation process - Google Patents
Isotopic separation processInfo
- Publication number
- CA1203773A CA1203773A CA000396471A CA396471A CA1203773A CA 1203773 A CA1203773 A CA 1203773A CA 000396471 A CA000396471 A CA 000396471A CA 396471 A CA396471 A CA 396471A CA 1203773 A CA1203773 A CA 1203773A
- Authority
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- Canada
- Prior art keywords
- uranium
- compounds
- process according
- anions
- laser
- 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
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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
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- Life Sciences & Earth Sciences (AREA)
- Biophysics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Lasers (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Process of the isotopic separation of uranium by a laser beam.
According to this process, at lease one light beam emitted by one or more lasers is trans-mitted into a gaseous mixture containing uranium 235 and uranium 238 compounds in order to bring about a selective excitation of the U235 or U238 compounds wherein the uranium 235 or uranium 238 compounds are of formula:
UO2XYBn in which X and Y are identical or different, inorganic or organic, monovalent anions, B is an organic strong Lewis base and n an integer at the most equal to 3.
Application to the enriching of uranium for nuclear fuels is envisaged.
Process of the isotopic separation of uranium by a laser beam.
According to this process, at lease one light beam emitted by one or more lasers is trans-mitted into a gaseous mixture containing uranium 235 and uranium 238 compounds in order to bring about a selective excitation of the U235 or U238 compounds wherein the uranium 235 or uranium 238 compounds are of formula:
UO2XYBn in which X and Y are identical or different, inorganic or organic, monovalent anions, B is an organic strong Lewis base and n an integer at the most equal to 3.
Application to the enriching of uranium for nuclear fuels is envisaged.
Description
.~ C"v~g ~G~
Isotopic separation process The present invention relates to an isotopic separation process according to which a given gaseous uranium isotopic compound is selectively and effectively separated from a gaseous mixture, certain of the substances constituting the gaseous compounds of the mixture being fo~med from uranium U 235 isotope and uranium U 238 isotope.
It is known that for producing so-called "enriched" nuclear fuels, it is necessary to separate the uranium 235 from the uranium 238. A promising way to carry out this separation is to use a power laser beam emitting a monochromatic light beam, the monochromaticity of the emitted light enabling the preferred excitation of a transition corresponding to one isotope of the uranium without exciting the other isotope. As a result of this excitation, there is either a dissociation of one of the isotopic compounds of the gaseous mixture (preferably the uranium 235 isotopic compound), in which case the dissociated compound can be physically or chemically separated from the is~topic mixture, or an activation of one of the isotopic compounds to bring it into a physico-chemical state in which it is able to react with an appropriate reagent, present for example in the gaseous mixture, so as to be able to then separate the resulting chemical compound in which is stored only one of the said isotopes of the gaseous mixture.
In the case of the uranyl ion several excitations are possible. Thus, this ion has an absorption range in IR light and in visible light.
The IR light is absorbed by exciting vibrations and rotations of the molecule and in particular the asymmetrical vibration of the Uo2 ion, which leads to an isotopic shift at a frequency of 940cm 1. The visible light is absorbed by electronic transitions of the same ion located at between 20,000 and 30,000 cm 19 on which an isotopic shift can also be observed, as a result of the fact that it occurs on the electronic transitions coupled to the vibrational transitions.
A selective excitation of these molecules can be obtained by using:
- a C02 laser, whose emission lines are in the range 900 to lOOOcm , i.e. a particularly interesting source because it is very powerful and inexpensive whereby according to the nature of the desired excitation either a pulsed laser of the transverse excitation type able to supply several joules by pulses, or a high power continuous laser (several KW) or a low power pulsed or continuous laser can be used;
- a continuous or pulsed dye laser emitting in the range 500 to 300nm.
It may also be of interest to supply the energy required for an excitation of the isotopic compound by the combination of a C02 laser and a W
source. In this case, the selectivity is only due to the C02 laser.
In order to bring about a selective action between the laser beam and the uranium cornpound, iit is generally preerable for the uranium compounds to be in the gaseous state, because in the condensed state the width of the well known IR and visible lines of the compounds exceeds the ïsotopic shift.
Moreover, in order to bring about a high efficiency of the separation process, it is necessary for the pressure of the gaseous compounds to be adequa*e to ensure adequate probability of the interactions between a photon of the laser beam and a molecule of the uranium compound.
To obtain an adequate gaseous pressure, it is necessary for the molecules of the gaseous compound of the uranium to be sufficiently volatile. The useEul pressures are then obtained by raising the gaseous isotopic mixtures to a ternperature of 100 to several hundred C. However, at this temperature9 it is also necessary for the uranium compounds to be stable to prevent any decomposition. Furthermore, it is advantageous for the uranium compounds to have no absorption spectrum other than the band to be irradiated~ in the emission range of either the C2 laser if this source is chosen~ or in the v;sible range in the vicinity of the absorptlons of the uranium compound in the case of irradiation with a dye laser.
Thus, the uranium compounds used must be sufficiently volatile, stable at the temperatures used and have a selective isotopic absorption spectrum at the wavelengths in question.
Therefore, the present invention relates to ~1 ~A~ ~1~
a process for the isotopic separation of uranium comprising transmitting into a gaseous mixture containing uranium 235 and uranium 238 compounds at least one light beam emitted by one or more lasers for bringing about a selective excitation of the uranium 235 or uranium 238 compounds~ wherein the uranium 235 and uranium 238 compounds are of formul.a: ;
in which X and Y are identical or different, mineral or organic, monovalent anions, B is an organic strong Lewis base and n an integer at the most equal to 3.
The uranium 235 and uranium 238 compounds in accordance with the above general formula have in particular the advantage of volatility~ stability and absorption properties in the in:Erared range and in the visible range, whic~ make them particularly appropriate as a ~aseous mixture for the separation of uranium isotopes by means of at least one laser beam.
Moreover, thesé uranium compounds are of considerable interest for isotopic separation by laser, because the selective excitation of the uranyl ion of the U235 or U238 compound in the visible or infrared range, leads to an autoreduction of this compound and transforms it into a non-volatile product, which can be easily separaLed from the gaseous mixture.
In these compounds, anions X and Y and Lewis base B are chosen in such a way that the compounds comply with the aforementioned volatility and stability reguirements. In general, the X and Y anions give the uranium compound an acceptable ~olatility such that the latter has an adequate pressure at the temperature at which the process is performed. The Lewis base B gives the uranium compound the necessary stability to ensure that it is not decomposed at said temperature.
In a process of this type, it is desirable to work with a partial pressure of the gaseous compounds exceeding 1/10 torr and preferably between l/lO and 1 torr.
Lower pressures are prejudicial to the efficiency due to the interaction of uranium compounds with the laser beam. Conversely, high pressures lead to reactions between the U235 and U238 compounds by collision and relaxation and consequently reduce the selectivity, because in this case the ~235 compound excited by the laser beam tends to react by collision with the U238 compound to which it transfers its activation energy, which is then lost. In addition, this leads to an autoreduction of the uranium 238 compound, which is obviously prejudicial to the separation of the U235 and U238 compounds.
Furthermore, the X and Y anions and the organic base B are chosen so that the uranium compound can have a vapour pressure equal to or above 0.1 torr ~31 ~f~
-5a~
at the temperature of the isotopic separation without being decomposed.
According to the invention, the monovalent ~/
~IL2~37~3 anions X and Y are advantageously chosen from the group consisting of the following anions:
_ Cl , Br , I , NO 3, SCN , as well as anions derived from fluorinated and perflùorinated aliphatic acids such as CF3COO . In certain cases, the volatility of the com-pound is improved by choosing anions X and Y of different types.
According to the invention, the strong organic Lewis base B ad~antageously has a high dipole moment, preferably at least equal to 5 Debye, and a high mole-cular volume, preferably at least equal to lOO. ~hus, the introduction of a Lewis base B having the afore-mentioned characteristics improves the stability of the uranium compound due on the one hand to the ion -dipole interaction which is proportional to the value o~the dipole moment, and on the other hand to the limited lability of the ligand due to the high molecular mass of the latter.
Examples of a suitable strong organic 1ewis base B are hexamethylphosphorotriamide OI formula:
~(CH3) 2N~ 3-P = Q, amine phosphates and amine oxides.
Preferably, the strong organid Lewis base B is hexame-thylphosphorotriamide.
Examples of uranium compounds which can be 5 used in the process of the invention are:
c ( 3 )2 (HMPT]2 -6a-U2 ( N03 ) ( SCN ) ( HMPT ) 2 U2 ( SCN ) 2 ( HMPT ) 2 . 5 [12 Br ( N03 ) ( HMPT ) 2 U2 (N03)2 (HMPT)2 t~O2B r 2 ( HMPT ) 2 /
~LZ~ 73 UO2I (NO3) (HMPT)2 U2C12 (HMPT)2 in which HMPT represents phosphorotriamide of formula 0= [P N(CH3)2~ 3-Preference is given to the use of the compound UO2 (CF3C00)2 (HMPT)2, which has a partial pressure of 1 torr at 230C and 0.1 torr at 160C, or the compound UO2 (NO3) (SCN) (HMPT)2 which has the pressure of 1 torr at 260 and 0.01 torr at 200C.
Such uranium compounds are particularly advantageous for the presen-t performance of the process according to the invention, because they have satisfactory volatility and stability characteristics, as well as an absorption band of the ion UO 2 between 900 and 960 cm 1, which can easily be irradiated by a C2 laser. Moreover, they do not have absorption bands linked with the X and Y anions or the base B, which are superimposed on the uranyl band /
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~2V377~
-7a-visible range.
~ ccording to a first embodiment of the process of the invention, a light beam emitted by a Co2 laser is transmitted into the gaseous mixture containing the uranium 235 and uranium 238 compounds.
The emission of a carbon dioxide laser takes place at around 950 cm 1, but can vary as a function of the isotopic composition of the carbon dioxide, the pressure, etc. In this wavelength range, a line of the uranium compound can coincide with an emission line of the laser for one of the isotopes and not for the other, thus, the isotopic shift on the asymme /
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3~2~773 vibration frequency of ~2 is 0.8 cm above the width of the laser line, making possible selectivity.
Thus~ by regulating the emission of the CO~
laser on an appropriate frequency, a selective excitation is obtained of the gaseous uranium 235 compound present in the mixture, which leads to an autoreduction of the U235 compound~ so that it is easy to ensure its separation from the gaseous mixture because the reduced compound is not volatile.
According to a second embodiment of the process according to the invention, a light beam emitted by a CO21aser and an ultraviolet light beam are transmitted into the gaseous mixture. In this case, the selectivity is only due to the CO2 laser.
According to a third embodiment of the process according to the invention, a visible light beam, whose wavelength is between 300 and 500 nanometres is ~ransmitted into the gaseous mixture containing the uranium 235 and uranium 238 comp~unds.
The visible light beam can be emitted by a dye laser~ such as a coumarin laser supplying a sufficien~ power in the uranyl ion absorption range.
Other aims and advantages of the invention can be gathered from the following description of examples given in an explanatory and non-limitative manner. The single drawing diagrammatically shows an apparatus for performing the process of the invention~
~V37'73 g The compound U02 (CF3C00)2 (HMPT)2 HMPT represents hexametapol of formula 0 = P L~N(CH3) 21 3 is placed in a sealed tank 2. By means of a flow-limiting valve 4 the compound is introduced into an irradiation cell for isotopic separation purposes.
The irradiation cell 6 is provided with a window 8 for the introduction of the laser beam 10. Cell 6 is made from a metal or refractory material not reacting with the gaseous uranium compound.
A known pumping device 18 circulates the gaseous compound in cell 6. A trap 16 collects the solid compound produced by laser irradiation corres~
ponding to one isotope. The entity is placed in an enclosure 14 thermostatically controlled to a tempera-ture of 235C. Laser 12 is either a t-ransverse excitation laser emitting pulses of 1 gigawatt, or a continuous laser of power 3 KW, with light pulses focused into the cell by means of e.g. a germanium lens 10. By tuning the frequency of the laser to an absorption frequency of 235 U02 in the compound, equal to 947 cm 19 it is possible to selectively decompose 3 U02 (CF3C00)2 (H~IPT)2 which gi~es a solid, brown, non-volatile compound, whereas 38uo2 (CF3C00)2 (HMPT)2 traverses the cell without being changed. ~lus, it is possibleJ for example, to recover uranium 235 in solid form in filter 16.
l~e pressure of U02 (C~3C00)2 (H~IPT)2 in irradiation cell 6 is 1 torr and the cell length is 20cm.
~2~3~7;3 The same compound U02(CF3C00)2 (HMPT)2 is introduced into the same irradiation cell. A continuous carbon dioxide laser of power 40 W focused in the cell is then used. The emission frequency of the laser is made to coincide with the absorption line of the uranium 235 compound. The excited U235 compound is reduced and then eliminated from the gaseous phase by filtration.
EX~MPLE 3 The compound U02(CF3C00)2 (HMPT)2 is :;ntroduced into the cell at 235 C, window 8 now being transparent to visible light, Irradiation takes place with a coumarin laser of energy 100 mJ on pulses of 100 nm, the emission frequency being regulated on a transition of the visible spectrum of U235 which differs from that of U238. The thus irradiated molecule undergoes degradation leading to a non-volatile compoundl which in this way can be eliminated from the gaseous phase.
.~
Isotopic separation process The present invention relates to an isotopic separation process according to which a given gaseous uranium isotopic compound is selectively and effectively separated from a gaseous mixture, certain of the substances constituting the gaseous compounds of the mixture being fo~med from uranium U 235 isotope and uranium U 238 isotope.
It is known that for producing so-called "enriched" nuclear fuels, it is necessary to separate the uranium 235 from the uranium 238. A promising way to carry out this separation is to use a power laser beam emitting a monochromatic light beam, the monochromaticity of the emitted light enabling the preferred excitation of a transition corresponding to one isotope of the uranium without exciting the other isotope. As a result of this excitation, there is either a dissociation of one of the isotopic compounds of the gaseous mixture (preferably the uranium 235 isotopic compound), in which case the dissociated compound can be physically or chemically separated from the is~topic mixture, or an activation of one of the isotopic compounds to bring it into a physico-chemical state in which it is able to react with an appropriate reagent, present for example in the gaseous mixture, so as to be able to then separate the resulting chemical compound in which is stored only one of the said isotopes of the gaseous mixture.
In the case of the uranyl ion several excitations are possible. Thus, this ion has an absorption range in IR light and in visible light.
The IR light is absorbed by exciting vibrations and rotations of the molecule and in particular the asymmetrical vibration of the Uo2 ion, which leads to an isotopic shift at a frequency of 940cm 1. The visible light is absorbed by electronic transitions of the same ion located at between 20,000 and 30,000 cm 19 on which an isotopic shift can also be observed, as a result of the fact that it occurs on the electronic transitions coupled to the vibrational transitions.
A selective excitation of these molecules can be obtained by using:
- a C02 laser, whose emission lines are in the range 900 to lOOOcm , i.e. a particularly interesting source because it is very powerful and inexpensive whereby according to the nature of the desired excitation either a pulsed laser of the transverse excitation type able to supply several joules by pulses, or a high power continuous laser (several KW) or a low power pulsed or continuous laser can be used;
- a continuous or pulsed dye laser emitting in the range 500 to 300nm.
It may also be of interest to supply the energy required for an excitation of the isotopic compound by the combination of a C02 laser and a W
source. In this case, the selectivity is only due to the C02 laser.
In order to bring about a selective action between the laser beam and the uranium cornpound, iit is generally preerable for the uranium compounds to be in the gaseous state, because in the condensed state the width of the well known IR and visible lines of the compounds exceeds the ïsotopic shift.
Moreover, in order to bring about a high efficiency of the separation process, it is necessary for the pressure of the gaseous compounds to be adequa*e to ensure adequate probability of the interactions between a photon of the laser beam and a molecule of the uranium compound.
To obtain an adequate gaseous pressure, it is necessary for the molecules of the gaseous compound of the uranium to be sufficiently volatile. The useEul pressures are then obtained by raising the gaseous isotopic mixtures to a ternperature of 100 to several hundred C. However, at this temperature9 it is also necessary for the uranium compounds to be stable to prevent any decomposition. Furthermore, it is advantageous for the uranium compounds to have no absorption spectrum other than the band to be irradiated~ in the emission range of either the C2 laser if this source is chosen~ or in the v;sible range in the vicinity of the absorptlons of the uranium compound in the case of irradiation with a dye laser.
Thus, the uranium compounds used must be sufficiently volatile, stable at the temperatures used and have a selective isotopic absorption spectrum at the wavelengths in question.
Therefore, the present invention relates to ~1 ~A~ ~1~
a process for the isotopic separation of uranium comprising transmitting into a gaseous mixture containing uranium 235 and uranium 238 compounds at least one light beam emitted by one or more lasers for bringing about a selective excitation of the uranium 235 or uranium 238 compounds~ wherein the uranium 235 and uranium 238 compounds are of formul.a: ;
in which X and Y are identical or different, mineral or organic, monovalent anions, B is an organic strong Lewis base and n an integer at the most equal to 3.
The uranium 235 and uranium 238 compounds in accordance with the above general formula have in particular the advantage of volatility~ stability and absorption properties in the in:Erared range and in the visible range, whic~ make them particularly appropriate as a ~aseous mixture for the separation of uranium isotopes by means of at least one laser beam.
Moreover, thesé uranium compounds are of considerable interest for isotopic separation by laser, because the selective excitation of the uranyl ion of the U235 or U238 compound in the visible or infrared range, leads to an autoreduction of this compound and transforms it into a non-volatile product, which can be easily separaLed from the gaseous mixture.
In these compounds, anions X and Y and Lewis base B are chosen in such a way that the compounds comply with the aforementioned volatility and stability reguirements. In general, the X and Y anions give the uranium compound an acceptable ~olatility such that the latter has an adequate pressure at the temperature at which the process is performed. The Lewis base B gives the uranium compound the necessary stability to ensure that it is not decomposed at said temperature.
In a process of this type, it is desirable to work with a partial pressure of the gaseous compounds exceeding 1/10 torr and preferably between l/lO and 1 torr.
Lower pressures are prejudicial to the efficiency due to the interaction of uranium compounds with the laser beam. Conversely, high pressures lead to reactions between the U235 and U238 compounds by collision and relaxation and consequently reduce the selectivity, because in this case the ~235 compound excited by the laser beam tends to react by collision with the U238 compound to which it transfers its activation energy, which is then lost. In addition, this leads to an autoreduction of the uranium 238 compound, which is obviously prejudicial to the separation of the U235 and U238 compounds.
Furthermore, the X and Y anions and the organic base B are chosen so that the uranium compound can have a vapour pressure equal to or above 0.1 torr ~31 ~f~
-5a~
at the temperature of the isotopic separation without being decomposed.
According to the invention, the monovalent ~/
~IL2~37~3 anions X and Y are advantageously chosen from the group consisting of the following anions:
_ Cl , Br , I , NO 3, SCN , as well as anions derived from fluorinated and perflùorinated aliphatic acids such as CF3COO . In certain cases, the volatility of the com-pound is improved by choosing anions X and Y of different types.
According to the invention, the strong organic Lewis base B ad~antageously has a high dipole moment, preferably at least equal to 5 Debye, and a high mole-cular volume, preferably at least equal to lOO. ~hus, the introduction of a Lewis base B having the afore-mentioned characteristics improves the stability of the uranium compound due on the one hand to the ion -dipole interaction which is proportional to the value o~the dipole moment, and on the other hand to the limited lability of the ligand due to the high molecular mass of the latter.
Examples of a suitable strong organic 1ewis base B are hexamethylphosphorotriamide OI formula:
~(CH3) 2N~ 3-P = Q, amine phosphates and amine oxides.
Preferably, the strong organid Lewis base B is hexame-thylphosphorotriamide.
Examples of uranium compounds which can be 5 used in the process of the invention are:
c ( 3 )2 (HMPT]2 -6a-U2 ( N03 ) ( SCN ) ( HMPT ) 2 U2 ( SCN ) 2 ( HMPT ) 2 . 5 [12 Br ( N03 ) ( HMPT ) 2 U2 (N03)2 (HMPT)2 t~O2B r 2 ( HMPT ) 2 /
~LZ~ 73 UO2I (NO3) (HMPT)2 U2C12 (HMPT)2 in which HMPT represents phosphorotriamide of formula 0= [P N(CH3)2~ 3-Preference is given to the use of the compound UO2 (CF3C00)2 (HMPT)2, which has a partial pressure of 1 torr at 230C and 0.1 torr at 160C, or the compound UO2 (NO3) (SCN) (HMPT)2 which has the pressure of 1 torr at 260 and 0.01 torr at 200C.
Such uranium compounds are particularly advantageous for the presen-t performance of the process according to the invention, because they have satisfactory volatility and stability characteristics, as well as an absorption band of the ion UO 2 between 900 and 960 cm 1, which can easily be irradiated by a C2 laser. Moreover, they do not have absorption bands linked with the X and Y anions or the base B, which are superimposed on the uranyl band /
/
/
/
,~
/
/
/
/
~2V377~
-7a-visible range.
~ ccording to a first embodiment of the process of the invention, a light beam emitted by a Co2 laser is transmitted into the gaseous mixture containing the uranium 235 and uranium 238 compounds.
The emission of a carbon dioxide laser takes place at around 950 cm 1, but can vary as a function of the isotopic composition of the carbon dioxide, the pressure, etc. In this wavelength range, a line of the uranium compound can coincide with an emission line of the laser for one of the isotopes and not for the other, thus, the isotopic shift on the asymme /
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/
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/
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/
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3~2~773 vibration frequency of ~2 is 0.8 cm above the width of the laser line, making possible selectivity.
Thus~ by regulating the emission of the CO~
laser on an appropriate frequency, a selective excitation is obtained of the gaseous uranium 235 compound present in the mixture, which leads to an autoreduction of the U235 compound~ so that it is easy to ensure its separation from the gaseous mixture because the reduced compound is not volatile.
According to a second embodiment of the process according to the invention, a light beam emitted by a CO21aser and an ultraviolet light beam are transmitted into the gaseous mixture. In this case, the selectivity is only due to the CO2 laser.
According to a third embodiment of the process according to the invention, a visible light beam, whose wavelength is between 300 and 500 nanometres is ~ransmitted into the gaseous mixture containing the uranium 235 and uranium 238 comp~unds.
The visible light beam can be emitted by a dye laser~ such as a coumarin laser supplying a sufficien~ power in the uranyl ion absorption range.
Other aims and advantages of the invention can be gathered from the following description of examples given in an explanatory and non-limitative manner. The single drawing diagrammatically shows an apparatus for performing the process of the invention~
~V37'73 g The compound U02 (CF3C00)2 (HMPT)2 HMPT represents hexametapol of formula 0 = P L~N(CH3) 21 3 is placed in a sealed tank 2. By means of a flow-limiting valve 4 the compound is introduced into an irradiation cell for isotopic separation purposes.
The irradiation cell 6 is provided with a window 8 for the introduction of the laser beam 10. Cell 6 is made from a metal or refractory material not reacting with the gaseous uranium compound.
A known pumping device 18 circulates the gaseous compound in cell 6. A trap 16 collects the solid compound produced by laser irradiation corres~
ponding to one isotope. The entity is placed in an enclosure 14 thermostatically controlled to a tempera-ture of 235C. Laser 12 is either a t-ransverse excitation laser emitting pulses of 1 gigawatt, or a continuous laser of power 3 KW, with light pulses focused into the cell by means of e.g. a germanium lens 10. By tuning the frequency of the laser to an absorption frequency of 235 U02 in the compound, equal to 947 cm 19 it is possible to selectively decompose 3 U02 (CF3C00)2 (H~IPT)2 which gi~es a solid, brown, non-volatile compound, whereas 38uo2 (CF3C00)2 (HMPT)2 traverses the cell without being changed. ~lus, it is possibleJ for example, to recover uranium 235 in solid form in filter 16.
l~e pressure of U02 (C~3C00)2 (H~IPT)2 in irradiation cell 6 is 1 torr and the cell length is 20cm.
~2~3~7;3 The same compound U02(CF3C00)2 (HMPT)2 is introduced into the same irradiation cell. A continuous carbon dioxide laser of power 40 W focused in the cell is then used. The emission frequency of the laser is made to coincide with the absorption line of the uranium 235 compound. The excited U235 compound is reduced and then eliminated from the gaseous phase by filtration.
EX~MPLE 3 The compound U02(CF3C00)2 (HMPT)2 is :;ntroduced into the cell at 235 C, window 8 now being transparent to visible light, Irradiation takes place with a coumarin laser of energy 100 mJ on pulses of 100 nm, the emission frequency being regulated on a transition of the visible spectrum of U235 which differs from that of U238. The thus irradiated molecule undergoes degradation leading to a non-volatile compoundl which in this way can be eliminated from the gaseous phase.
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Claims (10)
1. A process for the isotopic separation of uranium comprising transmitting into a gaseous mixture containing uranium 235 and uranium 238 compounds at least one light beam emitted by one or more lasers for bringing about a selective excitation of the uranium 235 or uranium 238 compounds, wherein the uranium 235 and uranium 238 compounds are of formula:
UO2XYBn in which X and Y are identical or different,inorganic or organic, monovalent anions, B is an organic strong Lewis base and n an integer at the most equal to 3, said uranium compounds having a partial pressure from 0.1 to 1 torr.
UO2XYBn in which X and Y are identical or different,inorganic or organic, monovalent anions, B is an organic strong Lewis base and n an integer at the most equal to 3, said uranium compounds having a partial pressure from 0.1 to 1 torr.
2. A process according to claim 1, wherein the organic Lewis base B has a dipole moment at least equal to 5 Debye and a molecular volume at least equal to 100.
3. A process according to claim 2, wherein the strong Lewis base B is hexamethylphosphorotriamide of formula: [(CH3)2 N]3 P=0
4. A process according to claim 2, wherein the strong Lewis base B is chosen from the group consisting of phosphates and amine oxides.
5. A process according to any one of the claims 1,2, or 3, wherein the anions X and Y are chosen from the group including the anions Cl-, Br, NO-3, SCN-, CF3COO- and anions derived from fluorinated or perfluorinated aliphatic acids.
6. A process according to claim 3, wherein the anions X and Y are trifluoroacetate anions of formula CF3COO- and wherein n is equal to 2.
7. A process according to claim 3, wherein the anions X and Y are constituted respectively by NO3 and SCN- and wherein n is equal to 2.
8. A process according to claim 1, wherein the U235 or U238 compounds are excited by transmitting a light beam emitted by a CO2 laser into the gaseous mixture.
9. A process according to claim 1, wherein the U235 or U238 compounds are excited by transmitting a visible light beam whose wavelength is between 300 and 500 nanometres into the gaseous mixture.
10. A process according to claim 1, wherein the uranium 235 or uranium 238 compounds are excited by transmitting a beam of light emitted by a CO2 laser and an ultraviolet light beam into the gaseous mixture.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7628726A FR2491771A1 (en) | 1976-09-24 | 1976-09-24 | ISOTOPIC SEPARATION METHOD USING A LASER BEAM |
| EP82400259A EP0086313A1 (en) | 1976-09-24 | 1982-02-15 | Process for separating isotopes of uranium by laser irradiation |
| CA000396471A CA1203773A (en) | 1976-09-24 | 1982-02-17 | Isotopic separation process |
| AU80577/82A AU8057782A (en) | 1976-09-24 | 1982-02-18 | Process of isotopic separation of uranium |
| JP57029095A JPS58146428A (en) | 1976-09-24 | 1982-02-26 | Isotope separation |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7628726A FR2491771A1 (en) | 1976-09-24 | 1976-09-24 | ISOTOPIC SEPARATION METHOD USING A LASER BEAM |
| EP82400259A EP0086313A1 (en) | 1976-09-24 | 1982-02-15 | Process for separating isotopes of uranium by laser irradiation |
| CA000396471A CA1203773A (en) | 1976-09-24 | 1982-02-17 | Isotopic separation process |
| AU80577/82A AU8057782A (en) | 1976-09-24 | 1982-02-18 | Process of isotopic separation of uranium |
| JP57029095A JPS58146428A (en) | 1976-09-24 | 1982-02-26 | Isotope separation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1203773A true CA1203773A (en) | 1986-04-29 |
Family
ID=27507261
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000396471A Expired CA1203773A (en) | 1976-09-24 | 1982-02-17 | Isotopic separation process |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0086313A1 (en) |
| JP (1) | JPS58146428A (en) |
| AU (1) | AU8057782A (en) |
| CA (1) | CA1203773A (en) |
| FR (1) | FR2491771A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4612097A (en) * | 1983-11-14 | 1986-09-16 | Westinghouse Electric Corp. | Process for separation of zirconium isotopes |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3951768A (en) * | 1971-02-05 | 1976-04-20 | Karl Gurs | Method of separating isotopes |
| US4357307A (en) * | 1979-12-21 | 1982-11-02 | Exxon Research And Engineering Company | Method of separating isotopes in which a compounding of selectivity is achieved by limiting the timing of the collection step |
| AU6011980A (en) * | 1979-12-21 | 1981-06-25 | Exxon Research And Engineering Company | Separation of isotopes |
| US4362669A (en) * | 1980-02-25 | 1982-12-07 | Exxon Research And Engineering Co. | Uranyl compounds employing a strong base |
-
1976
- 1976-09-24 FR FR7628726A patent/FR2491771A1/en active Granted
-
1982
- 1982-02-15 EP EP82400259A patent/EP0086313A1/en not_active Withdrawn
- 1982-02-17 CA CA000396471A patent/CA1203773A/en not_active Expired
- 1982-02-18 AU AU80577/82A patent/AU8057782A/en not_active Abandoned
- 1982-02-26 JP JP57029095A patent/JPS58146428A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| EP0086313A1 (en) | 1983-08-24 |
| FR2491771B1 (en) | 1984-12-21 |
| AU8057782A (en) | 1983-08-25 |
| FR2491771A1 (en) | 1982-04-16 |
| JPS58146428A (en) | 1983-09-01 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |