JPS6197020A - Separation and recovery cell - Google Patents

Abstract

PURPOSE:To miniaturize and simplify a cell vessel and to obtain efficiently the vapor of a uranium atom by using a gaseous carbon dioxide laser device. CONSTITUTION:A high-density laser beam 108 is irradiated on a uranium metal lic material 104 contained in a hearth 103 by a gaseous carbon dioxide laser 105 through a laser beam introducing pipe 107 provided at the inside of a separa tion and recovery cell vessel 101, and the material 104 is heated to high temp. and melted to obtain uranium vapor. Besides, a laser beam 114 of specified wavelength is irradiated by a laser device 111 for excited ionization through optical windows 113A and 113B for uranium atom vapor 109 to excite selectively only a uranium-235 atom in the vapor 109, and an ionized uranium-235 isotope 120 is obtained. Said uranium-235 isotope 120 is moved circularly by a magnetic field formed by a magnetic field generating coil 118 and deposited on a recovery electrode 116. Meanwhile, a uranium-238 isotope 121 is collected and removed by a recovery trap 122.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a laser concentration technology that utilizes the isotope shift of atoms and uses a laser to separate, recover, and concentrate a desired isotope from a metal raw material. The present invention relates to a separation and recovery cell that separates and recovers a desired isotope.

[Technical Background of the Invention The Ruther enrichment method separates and recovers uranium-235 isotope from uranium metal raw materials by utilizing minute differences in absorption spectra of isotopes of uranium atoms (hereinafter referred to as isotope shift). The principle of separation and recovery will be explained below with reference to Figure 2. Reference numeral 1 in the figure indicates a hearth, and a uranium raw material 2 is accommodated in the hearth 1. This hearth 1
The uranium raw material 2 contained therein is heated to a high temperature (200'K or more) by a high-temperature heating device 4 to obtain uranium atomic vapor 5. This uranium atomic vapor 5 is irradiated with a laser beam 6 of a specific wavelength corresponding to the absorption spectrum of the uranium-235 isotope, thereby selectively exciting only the uranium-235 isotope, and further irradiated with an ionizing laser beam 7 to ionize it. .

At this time, an electromagnetic field is created in the separation and recovery cell container (the configuration shown in FIG.
35 ion 8 (indicated by a black circle in the figure) is in the above electromagnetic field,
By changing its orbit, the neutral particle uranium-238 isotope 9
(indicated by a white circle in the figure) and is separated from the collection electrode 10 that has a negative potential and is collected. On the other hand, the neutral atom uranium-238 isotope 9 travels straight through the recovery electrode 10 and is collected and removed by the recovery trap 11 outside. The above is the basic principle of the separation and recovery cell.

As a method for heating the uranium metal raw material, methods such as an electron beam method, a resistance heating method, and a high frequency heating method are considered. In the case of the internal resistance heating method and the high-frequency heating method, the heating temperature of the hearth 1 is large, and the uranium-gold atom 2
High-temperature corrosion between the hearth 1 and the hearth 1 became a problem, and as a result, the life of the hearth 1 was shortened (and it was not suitable for long-term operation. Therefore, the electron beam method described above is generally adopted. This method is widely used in the fields of melting, welding, and vacuum deposition of high-melting point metals, and will be explained below with reference to Figure 3. Figure 3 shows a schematic configuration of high-temperature heating using the electron beam method. In the figure, reference numeral 21 indicates a filament electrode, and electrons heated by the filament electrode 21 and emitted from the filament electrode 22 are transferred to an accelerating power source 23 and an accelerating electrode 2.
4 and accelerate. Then, a magnetic field is applied to the emitted electrons by the magnetic field generating power supply 25 and the deflection coil 26, and the electron beam 27 is deflected to irradiate the entire surface of the uranium metal 29 housed in the hearth 28 and heat it to a high temperature to obtain uranium vapor. At this time, several hundred kilowatts of electron beam is required to heat the uranium metal 28 above 2000 degrees. The above is high temperature heating by electron beam method.

[Problems with the foreground technology] However, the above electron beam method has the following problems. That is, in the case of the electron beam method, electron emitting, accelerating, and deflecting sections must be installed within the separation and recovery cell container, which results in a large and complicated separation and recovery cell container. Furthermore, if the mechanism for generating an electron beam (electron gun section) is installed in the separation and recovery cell container as described above, there is a risk that it will be contaminated with uranium vapor, resulting in deterioration of electron emission performance. Therefore, a configuration that prevents contamination is required. Furthermore, if the filament electrode 22 is contaminated, complicated operations such as replacing the filament electrode 22 will be required.

As mentioned above, the electron beam method is a method in which the uranium metal raw material is heated and melted sequentially from the surface, so the degree of corrosion of the hearth 28 by the uranium gold 1i129 is small, but if the whole surface is irradiated (only the ion atoms 29) (the hearth 28 is also irradiated), the hearth 28 is at a higher temperature, so the hearth 28 must be provided with a cooling and heat removal mechanism such as a water cooling structure.

Furthermore, in the case of the electron beam method, a large number of power sources are required, resulting in a problem that control becomes complicated.

[Object of the Invention] The present invention has been made based on the above points, and its purpose is to provide a separation and recovery cell that can miniaturize and simplify the device and efficiently obtain uranium atomic vapor. Our goal is to provide the following.

[Summary of the Invention] That is, the separation and recovery cell according to the present invention includes a separation and recovery cell container, a hearth installed in the separation and recovery cell container and containing a radioactive element, and a hearth installed outside the separation and recovery cell container and in the hearth. A carbon dioxide laser device that irradiates the contained radioactive element with a laser beam, heats it at high temperature, and evaporates it;
A laser beam introduction window installed in the separation and recovery cell container for introducing a laser beam irradiated from the carbon dioxide laser device into the separation and recovery cell container; An excitation ionization laser device that selectively excites and ionizes only the body, and recovery that separately recovers specific isotopes and other isotopes separated by the laser beam irradiation of the excitation ionization laser device. The configuration includes a device.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a diagram showing an outline (8 configurations) of the separation and recovery cell according to this embodiment, and reference numeral 101 in the figure indicates a separation and recovery cell container.

A vacuum evacuation device 102 is connected to this separation and recovery cell container 101 via a pipe 102A.
01 is a vacuum. The above separation and collection cell container 10
A hearth 103 is installed in the lower part of the uranium 1, and a uranium raw material 104 such as uranium metal or a uranium compound is housed in the hearth 103. Hearth 103 above
The material used is copper, which has high thermal conductivity.

Tantalum or tungsten, which has a high melting point, is used. A carbon dioxide (CO2) laser device 105 is installed outside the separation and recovery cell container 101, and the carbon dioxide laser device 105 irradiates the uranium metal material 104 with a laser beam to heat it at a high temperature and melt it. , a configuration for obtaining uranium vapor. The carbon dioxide laser device 105 includes a carbon dioxide laser tube 105A and its auxiliary equipment 105B. As the carbon dioxide laser device 105, a high-output device with an output of several hundred kilowatts is adopted, and a laser beam installed inside the separation and recovery cell container 101 is directed toward the uranium metal material 104 housed in the hearth 103. A high-density laser beam 108 is irradiated through the introduction tube 107. The above laser beam introduction tube 10
A condensing optical system (not shown) is installed at 7 to adjust the aperture of the laser beam. The above carbon dioxide laser device 10
The uranium metal material 104 that has been irradiated with the high-density laser beam 108 from 5 is heated to a high temperature of about 2600 to 2700'K and vaporized to become uranium vapor 109.

A laser device for excitation ionization 111 is connected to the separation and recovery cell container 101.
11 is an excitation ionization laser tube 111A and ancillary equipment 111B
It consists of This excitation ionization laser device 111
The optical windows 113A, 1 are formed in the uranium atomic vapor 109 by
Uranium-235 in the vapor 109 is irradiated with a laser beam 114 of a specific wavelength (mainly 5915.4A6) through 13B.
Selectively excite only atoms and ionize them to produce uranium-2
Generates 35 ions. The excitation ionization laser device 111 is required to be able to emit light at a wavelength that precisely matches the absorption spectrum of uranium atoms, and at the same time has a high average output and high efficiency. Therefore, a combination of a copper vapor laser or an excimer laser is used as a dye laser and its excitation power source. Further, among uranium atoms, uranium-238 and other uranium-238 isotopes other than the uranium-235 isotope pass through as neutral particles without being excited and ionized.

Next, the recovery facility 115 for recovering the ionized uranium-235 isotope 120 will be explained.
Reference numeral 16 indicates a recovery electrode that attaches and recovers the ionized uranium-235 isotope 120, and an electrolytic generation power source 117 is connected to this recovery electrode 116. On the other hand, a magnetic field generating coil 118 is wound around the outer circumferential side of the separation and recovery cell container 101.
A power supply 119 for generating a magnetic field is connected to. The uranium-235 isotope 120 is deposited on the recovery electrode 116 while moving in a circular motion due to the magnetic field generated by the magnetic field generating coil 118. On the other hand, the uranium-238 isotope 121, which is a neutral particle, passes through the electromagnetic field and is collected and removed by the recovery trap 122.

According to the separation and recovery cell according to the present embodiment, since the carbon dioxide laser device 105 is used, each vessel is connected to the separation and recovery cell container 101 as in the case of the electron beam method.
Since high-temperature heating is possible by irradiating the high-density laser beam 108 from the outside of the separation and recovery cell container 101, the separation and recovery cell container 10
1 can be made smaller and simpler, and since it does not require multiple power sources unlike the electron beam method, it is possible to simplify the control system and the control itself. Become. Further, the output, density (aperture), irradiation position, etc. of the laser beam 108 irradiated by the auxiliary equipment 105B and the laser beam introduction window 107 can be adjusted to desired values, and as a result, uranium atomic vapor is produced.

This makes it possible to easily control the occurrence of 109.

By narrowing down the laser beam 108, it is possible to irradiate only the uranium metal raw material 104 and heat it to a high temperature, instead of irradiating the entire surface as in the conventional method, and it is possible to suppress the temperature rise of the hearth 103, and to heat the hearth 10". 4- can be made unnecessary, and uranium vapor 109 can be efficiently generated. Also, high-temperature corrosion of the hearth 103 and contamination by uranium vapor can be prevented. Not only can the life be extended, but also the burden required for maintenance and inspection can be reduced.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and the same effects can be achieved even if the present invention is applied to a separation and recovery cell configured to include a mechanism for preliminarily heating the hearth, for example.

[Effects of the Invention] As detailed above, the separation and recovery cell according to the present invention includes a separation and recovery cell container, a hearth installed in the separation and recovery cell container and containing a radioactive element, and a hearth installed outside the separation and recovery cell container. a carbon dioxide gas laser device that irradiates the radioactive element installed and housed in the hearth with a laser beam and evaporates it by heating it to a high temperature, and a separation and recovery cell container that is installed in the separation and recovery cell container and irradiates the laser beam from the carbon dioxide laser device. an excitation ionization laser device installed in the separation and recovery cell container that selectively excites and ionizes only a specific isotope of the evaporated radioactive element; This configuration includes a recovery device that separately recovers a specific isotope separated by laser beam irradiation from an ionization laser device and other isotopes.

Therefore, there is no need to house an enclosure for evaporating the radioactive element by heating it to a high temperature in the separation and recovery cell container, and the separation and recovery cell container can be made smaller and the structure can be simplified accordingly. The burden required for maintenance and inspection work can be reduced, and the integrity of the laser beam generating section can be maintained by preventing contamination by steam.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a separation and recovery cell showing an embodiment of the present invention, FIG. 2 is a diagram for explaining the principle of the separation and recovery cell, and FIG. 3 is a diagram for explaining the electron beam method. . 101... Separation and recovery cell container, 103... Hearth,
104... Uranium metal material, 105... Carbon dioxide laser device, 107... Laser beam introduction window, 108...
...Laser beam, 109...Ion vapor, 111.
・・Excitation ionization laser device, 115 ・・Collection device, 12
0...Uranium-235 isotope, 121...Uranium-
238 isotope. Part I N

Claims (2)

[Claims] (1) A laser beam is irradiated on a separation and recovery cell container, a hearth installed inside the separation and recovery cell container that houses the radioactive element, and a radioactive element installed outside the separation and recovery cell container and housed in the hearth. a carbon dioxide laser device that heats to a high temperature and evaporates; a laser beam introduction window that is installed in the separation and recovery cell container and that introduces the laser beam irradiated from the carbon dioxide laser device into the separation and recovery cell container;
An excitation ionization laser device installed in the separation and recovery cell container selectively excites and ionizes only a specific isotope of the evaporated radioactive elements, and a laser beam irradiation from the excitation ionization laser device separates the radioactive elements. 1. A separation and recovery cell comprising a recovery device that separately recovers a specific isotope and other isotopes. (2) Separation and recovery according to claim 1, wherein the laser beam introduction window is provided with an aperture adjustment mechanism that adjusts the aperture degree of the laser beam irradiated from the carbon dioxide laser device. cell.