JPH0471623A - Isotope separator - Google Patents

Abstract

PURPOSE:To enhance the operation efficiency by providing a device for continuously supplying plural recovery plates to a vapor passage, a device for successively moving the recovery plates in the vapor passage and a device for continuously recovering the recovery plate vapor-deposited with an isotope, etc. CONSTITUTION:The entire separation cell 11 is divided into a central chamber 25 contg. vaporization crucibles 2, a belt conveyor 6, etc., a handling chamber 26 contg. a recovery plate supply device 13, and a handling chamber 27 contg. a recovery plate collector 15. The ionized isotope is deflected by an electric field toward a product recovery plate 22 acting as a cathode and vapor-deposited on its surface, and the unionized neutral metal ion, etc., are vapor-deposited on the inner surface of a recovery plate main body 20. A recovery unit 12 is sent toward the collector 15 by a belt conveyor 16, placed on a recovery plate collecting rack 19 and discharged from the chamber 27. The recovery unit 12 is placed on the recovery plate mounting rack of the supply device 13 in the chamber 26.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an isotope separation device, and in particular, it simplifies the recovery operation of metal raw materials and enables continuous operation for a long time.
This invention relates to an isotope separation device that improves the operating economy of the device.

(Prior technology) Metal atom isotope separation equipment using the atomic laser method using a laser beam has a much higher isotope separation efficiency than conventional isotope separation equipment using gas diffusion methods or centrifugation methods. ,Are better. For this reason, isotope separation equipment that uses the atomic laser method does not require repeating the same separation process in multiple stages in a cascade system until a specific isotope reaches a predetermined concentration level, and the entire separation equipment can be made smaller and more compact. , has excellent economic efficiency.

An isotope separation device for metal atoms using an atomic laser method, such as a conventional uranium enrichment device, is generally constructed as conceptually shown in FIG. 2 will be installed. A metal raw material 3 to be isotopically separated is stored in a storage recess opened above the evaporation crucible 2.

After the inside of the separation cell 1 is made into a vacuum state, the inside of the evaporation ruppo 2 is irradiated with an electron beam B emitted from an electron gun 4 as an electron beam generator after being deflected by the deflection magnetic field of an external magnetic field coil 5. By being irradiated with the electron beam B, the metal raw material 3 is heated to a high temperature of, for example, 3,000 ℃, and is melted and evaporated to generate a metal vapor flow A.

This metal vapor stream rises within the separation cell 1, and the rising metal vapor stream A is irradiated with selective excitation laser light 6. By this laser beam irradiation, specific isotope metal atoms (metal vapor) C, which are characterized by recovery, are selectively excited in the metal vapor flow A,
Ionized (ionized). The ionized isotope C is
When passing between the electrodes 7 in which the positive electrode 7a and the negative electrode 7b are arranged alternately, only the ionized isotope C is attracted and adsorbed to the surface of the negative electrode 7b, which is a voltage application and collection plate.
It will be collected.

On the other hand, isotope metal atoms (metal vapor) that are not ionized pass through between the electrodes without being affected by the electric field between the electrodes 7 as neutral atoms, and are collected by a neutral atom collector placed on the secondary side of the electrode 7. It is sucked into the collection plate 8 and collected.

When a certain amount of isotope etc. has accumulated on the collection plate, the apparatus is stopped, and after releasing the vacuum inside the separation cell 1, the collection plate is taken out from inside the separation cell 1 and the isotope that will become the product is collected. The metal components were recovered by heating and melting in a heating furnace, or scraped off from a recovery plate and processed and recovered in batches. Some of the recovered metal raw materials will be used for evaporation in Rupo 2.
The waste is recycled and reused, increasing the efficiency of using expensive raw materials. Then, when restarting the device, inside the separation cell 1,
A complicated operation was required to reduce the pressure again and adjust it to a predetermined degree of vacuum.

In order to eliminate the above-mentioned complicated operations and to enable the equipment to operate continuously over long periods of time and process large amounts of metal raw materials, as shown in Figure 6, a A liquefaction reflux method is also being trialled, in which isotopes are melted by heating and continuously recovered in a liquid state. This method has been applied to pilot plants and commercial plant-scale systems for atomic laser isotope separation systems such as uranium enrichment.

A receiving groove 9 is disposed in the longitudinal direction of the lower end of each cathode 7b, which serves as a product collection plate of this isotope separation device, and a heater (not shown) is built therein. The isotope deposited on the surface of each cathode 7b is heated to above its melting point by a heater and melted, and the melted isotope flows down the receiving groove 9 and gutter 10 as shown by the arrow, and is finally recovered as a product. It is collected into the container 11.

(Problem to be solved by the invention) However, when the liquefaction reflux method as shown in Fig. 6 is adopted, the molten metal is solidified in the entire path from the cathode as a product collection plate to the product collection container. It is necessary to maintain the temperature at a high temperature that allows it to flow down without water. For example, in order to liquefy and recover uranium isotopes, it is necessary to heat and maintain the uranium at a high temperature of at least about 1180° C. or higher, which is the melting point of uranium. The power supplied to the heater for this heating is extremely large, and is equivalent to the power supplied to the electron gun used for heating and evaporating the metal raw material and the power for selective excitation laser beam oscillation, which reduces the energy efficiency of the isotope separation device. This is one of the reasons for the significant decline in

In addition, in order to put the liquefaction reflux method in the separation cell into practical use, solutions must be solved such as maintaining a high temperature in the reflux route, making the reflux route constituent materials resistant to corrosive raw materials such as uranium isotopes, and simplifying the maintenance and management of heaters. The current situation is that there are many issues that need to be addressed.

The present invention was made to solve the above-mentioned problems, and it can be used for a long time without liquefying and refluxing isotopes, etc. in the separation cell, and while maintaining the degree of vacuum in the separation cell. Enables continuous processing operation of metal raw materials across
The purpose of the present invention is to provide an isotope separation device with significantly improved recovery operations and operational economy.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention heats and evaporates a metal raw material containing a plurality of isotopes in a separation cell to generate a vapor flow, and recovers contained in the vapor flow. In an isotope separation device that separates a target isotope and other components by vapor-depositing them on recovery plates, a recovery plate replenishing device that continuously supplies a plurality of recovery plates to the vapor flow path; A collection plate moving device that sequentially moves the collected collection plates along the vapor flow path, and a collection plate collection device that continuously collects the collection plates on which isotopes and the like have been deposited are provided in the separation cell. do.

(Function) According to the isotope separation device having the above configuration, a plurality of recovery plates are continuously supplied to the steam flow passage by the recovery plate supply device, and the supplied recovery plates are moved to the steam flow passage by the recovery plate moving device. is moved along. During this movement, electrically separated isotopes and other metal raw material components are deposited on the surface of the collection plate. The collection plate on which isotopes and the like have been deposited is continuously collected by a collection plate collection device. The multiple collected plates are heated all at once in a special heating furnace, etc.
Isotopes etc. are efficiently recovered in a molten state.

According to the device of the present invention, multiple collection plates are continuously replenished and collected while maintaining the vacuum state in the separation cell, making it possible to process a large amount of metal raw materials over a long period of time. Compared to a method in which the collection plates are taken out by batch operations, the collection operation is significantly simplified, and the operating efficiency of the device can be greatly improved. In other words, even if the amount of isotope deposited on one collection plate reaches its limit, other collection plates are newly replenished, so the device can be operated for a long time without being restricted by the evaporation capacity of the collection plate. It is possible to operate continuously, which greatly increases the operating economy of the device.

(Example) Next, an example of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side sectional view showing one embodiment of the present invention. Note that the same elements as in the conventional example shown in FIGS. 5 and 6 are given the same reference numerals, and redundant explanation thereof will be omitted.

That is, the isotope separation apparatus according to this embodiment heats and evaporates the metal raw material 3 containing a plurality of isotopes in the separation cell 1 to generate a vapor flow A, and aims to recover the vapor contained in the vapor flow A. In an isotope separation device that separates isotopes and other components by vapor-depositing them onto recovery plate units 12, recovery plate replenishment involves continuously replenishing the passage of the vapor flow A with a plurality of recovery plate units 12. device 13;
A belt conveyor 16 as a recovery plate moving device 14 that sequentially moves the replenished recovery plate units 12 along the steam flow path, and a recovery plate collection device 15 that continuously collects the recovery plate units 12 on which isotopes and the like have been deposited. are provided in the separation cell 1.

At the bottom of the separation cell 1 in the axial direction, three evaporation units 2 containing the metal raw material 3 are arranged, and on both sides of the upper part,
A belt conveyor 16 is provided as a recovery plate moving device 14 that moves the recovery plate unit 12 at a constant speed along the path of the steam flow A, and a recovery plate replenishing device 13 is provided at both ends of the belt conveyor 16, respectively. and a collection plate collection device 15 are provided.

The collection plate replenishing device 13 includes a collection plate mounting pedestal 17 that moves up and down with a plurality of unused collection plate units 12 placed thereon, and a collection plate unit 12 stocked at the top of the pedestal 17. It consists of a collection plate extruder 18 that moves forward and backward so as to push out toward one end of the belt conveyor 16.

The recovery plate collection device 15 also includes a recovery plate collection mount 19 that sequentially receives the recovery plate units 12 discharged from the other end of the belt conveyor 16 and on which isotopes have been deposited, and stacks them at a predetermined position. Although omitted, recovery plate unit 1
An enrichment monitor for measuring the enrichment of product isotopes deposited on the second unit, and a heating furnace that heats multiple used collection plate units to melt and recover product isotopes and other components deposited on the units. It consists of equipment such as.

Each collection plate unit 12 includes a collection plate main body 20 curved in a trapezoidal cross section, and a collection plate main body 20 as shown in FIG.
It consists of a plurality of product collection plates 22 protruding from the lower surface of the main body 20 at predetermined intervals through fixed columns 21.
Both side edges of are placed on the belt conveyor 16 and configured to be movable along the steam flow path.

A positive electrode plate 23 is disposed between adjacent product recovery plates 22, and a recovery electrode is formed by this positive electrode plate 23 and the product recovery plate 22 functioning as a negative electrode. Positive electrode plate 2
Both ends of 3 are fixed within the separation cell 1 by supports (not shown), and are mechanically separated from the collection plate unit 12.

Further, in this embodiment, a raw material recovery plate 24 is provided which has the function of guiding the vapor flow A generated from the evaporation crucible 2 toward the recovery electrode and the function of recovering raw materials to be reused. This raw material recovery plate 24 also includes the recovery plate unit 1.
2, it is divided into units, and a plurality of raw material recovery plates 24 are sequentially replenished along both sides of the steam passage and moved while being placed on a belt conveyor 16a.
Constructed to be eventually collected.

As shown in FIGS. 3 and 4, the entire separation cell 1 includes a central chamber 25 that accommodates the evaporation crucible 2, the belt conveyor 16, etc., and a nodding chamber 26 that accommodates the recovery plate replenishing device 13. , collection board collection device 15
It is divided into a holding chamber 27 and a holding chamber 27 for accommodating the holding chamber 27. Each of the chambers 25 to 26 includes vacuum pumps 28a, 28b, and 28c for reducing the pressure inside, a side glass 29 for allowing the operator to see through the inside, and
Sealing valves 30a and 30b are provided for opening and closing sealing plates (not shown) interposed between the valves 5 and 27. Further, the selective excitation laser beam 6 irradiated onto the vapor flow A is configured to enter the central chamber 25 through the handling chamber 26 .

When storing the collection plate unit 12 in the separation cell 1,
Close the sealing plate in advance and open the no. 1 handling chamber 2.
6 is carried out in an open state to the atmosphere.

Even in this case, the interior of the central chamber 25 is sealed by the sealing plate, so that it is maintained in a vacuum state. Next, vacuum pump 28 moves inside this nodling chamber 26.
The handling chamber 2 is evacuated by b.
When the degree of vacuum in the chamber 6 becomes equal to that in the central chamber 25, the sealing valve 30a is opened, and the sealing plate disposed between both chambers 25 and 26 is opened.

A plurality of recovery plate units 12 housed in the handling chamber 26 are stacked and stored in multiple stages above the recovery plate mounting frame 13. The stored collection plate units 12 are sequentially pushed out onto the belt conveyor 16 by a collection plate extruder 18 starting from the one in the upper stage. The extruded collection plate unit 12 is placed on a belt conveyor 16 and moves horizontally in the direction of the collection plate collection device 15 through the photoreaction section at a constant moving speed.

On the other hand, the metal raw material 3 in the evaporation crucible 2 is irradiated with a heating electron beam from an electron gun, and the metal raw material 3 is melted and evaporated to become a vapor flow A. The steam flow A is guided by the raw material recovery plate 24 and flows toward the recovery plate unit 12 . The vapor flow A is selectively excited to become a cationized isotope by the selective excitation laser beam 6 irradiated to the photoreaction area between the product recovery plate 22 and the positive electrode plate 23. The ionized isotope is deflected in the direction of the product collection plate 22, which functions as a negative electrode, by the electric field formed between the electrodes, and is deposited on the surface of the product collection plate 22. On the other hand, neutral metal atoms etc. that have not been ionized pass through the recovery electrode section and are deposited on the lower surface of the recovery plate main body 20.

A recovery plate unit 12 on which a certain amount of product isotopes and other components to be recovered is deposited is transported to a belt conveyor 16.
are sequentially sent in the direction of the collection board collection device 15, and are sent out onto the collection board collection stand 19, starting with the one at the tip,
They are stored in a stacked state.

By the way, the vapor flow A generated by evaporation from the evaporation crucible 2
It has been confirmed that most of the evaporation amount adheres to the raw material recovery plate 24, and the amount of adhesion may reach 60% of the total evaporation amount. However, as shown in FIG.
4 is sequentially replenished and further moved by the belt conveyor 16a, and is collected in the same manner as the collection plate unit 12. By adopting a method in which the metal raw materials adhering to the raw material collection plate 24 can be easily collected, the metal raw materials can be recycled. Easy to use.

However, even if a large amount of metal raw materials adheres to the raw material recovery plate 24, it does not have a large effect on the isotope separation efficiency, so the raw material recovery plate 24 is not mobile and after long-term operation. A method may also be adopted in which the materials are collected and processed from within the separation cell 1 in bulk as appropriate during maintenance and inspection.

The large number of collection plate units 12 collected in the collection plate collection device 15 are then taken out from the handling chamber 27. In the take-out operation, first close the shutoff valve 30b, and then run the vacuum pump 2 inside the handling chamber 27.
Perform vacuum evacuation at 8c. Then, when the degree of vacuum in the handling chamber 27 becomes equal to that in the central chamber 25, the sealing valve 30b is opened, the sealing plate provided between the central chamber 25 and the handling chamber 27 is opened, and the collected After moving the recovery plate unit 12... into the handling chamber 27, the shutoff valve 3 is opened again.
By closing 0b, the space between the central chamber 25 and the handling chamber 27 is sealed off. Thereafter, the handling chamber 27 is opened to vacuum, and the collected collection plate unit 12 is taken out.

The recovery plate unit 12 taken out into the atmosphere is decomposed into a product recovery plate 22 and a recovery plate main body 20, and then an enrichment monitor is used to measure the enrichment of the product isotope deposited on each surface. Based on the measurement results, the products are classified into products, waste products, and reused products. Parts for each category are inserted into a dedicated heating furnace, and products, waste products, and reusable products are individually melted and collected.

The reused product is again supplied into the evaporator 2 as a metal raw material 3.

As described above, by using the isotope separation device according to this embodiment, a plurality of recovery plates are continuously supplied to the vapor flow path without liquefying and refluxing the metal raw material 3 in the separation cell 1. The product isotope and the reusable isotope are deposited on the unit 12, and the collection plate unit 12 is taken out of the separation cell 1 all at once, and the concentration monitor clearly distinguishes between the product isotope, the waste product, and the reuse product. The method uses a special heating furnace to melt and recover the cells after the
Compared to the internal liquefaction reflux method, the heat utilization efficiency is higher, and the advantage is that melting and recovery can be carried out reliably.

In particular, unlike conventional devices in which a single collection plate is fixedly arranged and the collection operation is performed batchwise, in this embodiment, a plurality of collection plate units 12 are continuously replenished, moved, and collected. As a system, it becomes possible to operate the apparatus continuously for a long time while maintaining the degree of vacuum in the separation cell 1, and it is possible to efficiently separate a large amount of metal raw materials.

〔Effect of the invention〕

As explained above, according to the isotope separation apparatus according to the present invention, a plurality of collection plates are continuously replenished and collected while maintaining a vacuum state in the separation cell, so a large amount of metal raw materials can be collected for a long period of time. It is now possible to perform continuous processing over a period of time, and the collection operation is significantly simplified compared to the conventional method of taking out the collection plates in batch operations, making it possible to significantly improve the operating efficiency of the device. In other words, even if the amount of isotope deposited on one collection plate reaches its limit, other collection plates are newly replenished, so the device can be operated for a long time without being restricted by the evaporation capacity of the collection plate. It is possible to operate continuously, which greatly increases the operating economy of the device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the isotope separation device according to the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a plan view showing the outer shape of the separation cell. Fig. 4 is a side view showing the external shape of the separation cell, Fig. 5 is a sectional view conceptually showing the configuration of a conventional isotope separation device, and Fig. 6 is a conventional device showing the mechanism for recovering separated isotopes. FIG. DESCRIPTION OF SYMBOLS 1... Separation cell, 2... Crucible for evaporation, 3... Metal raw material, 12... Recovery plate unit, 13... Recovery plate supply device, 14... Recovery plate moving device, 15. ...Recovery plate collection device, 16.16a...Belt conveyor, 22
...Product recovery plate, A...Metal vapor flow. Figure 3 Figure 4rs Figure 6

Claims (1)

[Claims] A metal raw material containing multiple isotopes is heated and evaporated in a separation cell to generate a vapor flow, and the isotope to be recovered and other components contained in the vapor flow are respectively deposited on a recovery plate. In the isotope separation device that separates,
A recovery plate replenishing device that continuously supplies a plurality of recovery plates to the vapor flow path, a recovery plate moving device that sequentially moves the supplied recovery plates along the vapor flow path, and a recovery plate with vapor-deposited isotopes, etc. An isotope separation device characterized in that a recovery plate collection device for continuously collecting plates is provided in a separation cell.