JP2000292593A - Actinide oxide reduction equipment - Google Patents

Abstract

(57) Abstract: Provided is an actinide oxide reduction device that obtains a high reduction ratio of an actinide oxide to actinide metal. A holding container (5) containing a molten salt (2) is provided inside the holding container (5), immersed in the molten salt (2), the molten salt (2) can be circulated, and an actinide is contained in the molten salt (2). A recovery container 6 to which the oxide 3 and the reducing agent 4 for reducing the oxide 3 are added, and a stirring device 7 for diffusing the actinide oxide 3 and the reducing agent 4 into the molten salt 2 in the recovery container 6, The recovery container 6 has a separating means for separating the molten salt 2 and the reduction product after the completion of the reduction reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actinide oxide reducing device for reducing actinide oxide in spent fuel generated from, for example, a nuclear power plant to actinide metal with a reducing agent.

[0002]

2. Description of the Related Art Conventionally, as a means for reducing an actinide oxide to an actinide metal, a method using an alkali metal such as Li (lithium) or an alkaline earth metal such as Mg (magnesium) as a reducing agent is known. I have.

A conventional example of an actinide oxide reducing device will be described below with reference to FIG. In FIG. 23, the conventional actinide oxide reduction device is a reaction vessel 1
A molten salt 2 is accommodated in the reaction vessel 1. After the actinide oxide 3 is immersed in the molten salt 2, a reducing agent 4 such as Li or Mg is charged. And
Above the molten salt 2 in the reaction vessel 1, an inert gas such as argon gas is sealed.

In such an actinide oxide reducing apparatus, at a predetermined reaction temperature, the actinide oxide 3 is reduced in the molten salt 2 by the reducing agent 4 to reduce the actinide metal as a reduction product. Obtainable.

[0005]

In the above-described conventional apparatus for reducing actinide oxide, the concentration of the reducing agent oxide in the molten salt 2 increases as the reduction process proceeds, so that the reduction reaction is suppressed. There is. In addition, there is a problem that the reducing agent oxide adheres to the surface of the actinide oxide 3 and hinders the contact between the actinide oxide 3 and the reducing agent 4 to lower the reduction rate.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an actinide oxide reduction apparatus that can obtain a high reduction ratio of an actinide oxide to actinide metal.

Another object of the present invention is as follows.
It is an object of the present invention to provide an actinide oxide reducing device that shortens the time required for recovering a reduction product and recovering a molten salt and improves the operation efficiency of the device.

[0008]

In order to achieve the above object, in the actinide oxide reduction apparatus according to the present invention, the invention according to claim 1 includes a holding vessel containing a molten salt,
A recovery container installed inside the holding container and immersed in the molten salt so that the molten salt can flow therethrough, and an actinide oxide and a reducing agent for reducing the actinide oxide are added to the molten salt, respectively. A stirrer for diffusing the actinide oxide and the reducing agent into the molten salt in the recovery container, wherein the recovery container includes a separation unit that separates the molten salt and a reduction product after the completion of the reduction reaction. It is characterized by having.

According to the first aspect of the present invention, the molten salt, the actinide oxide and the reducing agent contained in the collecting container in the holding container are stirred by a stirring device, and the reducing agent is suspended in the molten salt. As a result, the reducing agent oxide attached to the surface of the unreduced actinide oxide is peeled off. Accordingly, a sufficient concentration of the reducing agent in the molten salt can be maintained, and sufficient contact between the reducing agent and the actinide oxide can be obtained, so that a high reduction rate can be obtained.

[0010] Further, since there is a separation means for separating the molten salt from the reduction product after the completion of the reduction reaction, only the reduction product can be selectively recovered.

According to a second aspect of the present invention, in the actinide oxide reducing apparatus according to the first aspect, a heating space for holding the molten salt at a constant temperature equal to or higher than a melting point and a room temperature space near room temperature are thermally separated. And a heat shielding member for shielding.

According to the second aspect of the present invention, the heat dissipation from the heating space to the room temperature space is suppressed by the heat shielding member, so that the amount of heat consumed for heating the heating space is suppressed low and the temperature rise in the room temperature space is avoided. As a result, a healthy working environment can be secured.

According to a third aspect of the present invention, in the apparatus for reducing actinide oxide according to the first or second aspect, a through-path is provided that penetrates the heat shielding member and faces the inside of the recovery container. It is characterized in that it is used as a reducing agent charging hole for directly charging the agent.

According to the third aspect of the present invention, since the reducing agent can be introduced even during the reduction reaction, the reducing agent can be obtained without a shortage of the reducing agent.

According to a fourth aspect of the present invention, in the actinide oxide reducing apparatus according to the third aspect, instead of the reducing agent introduction hole, the through passage is sampled by sampling a salt phase in a molten state as needed. It is characterized in that it is used as a hole.

According to the fourth aspect of the present invention, by collecting a sample during the reduction reaction, the molten salt during operation, actinide oxide, a reducing agent for reducing the salt, and a metal formed by reducing the actinide oxide It is possible to grasp the state of the actinide and the reducing agent oxide generated after reducing the actinide oxide.

According to a fifth aspect of the present invention, there is provided the actinide oxide reducing device according to the third aspect, wherein the actinide oxide is loaded into the heating space by the through-path instead of the reducing agent introduction hole. It is characterized in that it is used as an input hole.

According to the fifth aspect of the present invention, since actinide oxide is directly loaded into the molten salt, it is not necessary to simultaneously load the salt before melting and the actinide oxide. Since the problem of the impurities generated from the oxide being adsorbed by the salt is avoided and a high-purity molten salt is obtained, the reduction rate is improved.

According to a sixth aspect of the present invention, in the actinide oxide reducing device according to the third aspect, instead of the reducing agent introduction hole, the through passage is provided with a pipe for supplying an inert gas into the heating space. It is characterized in that it is used as an inert gas supply pipe insertion hole to be inserted and an inert gas discharge pipe insertion hole for releasing pressure increased by the supplied inert gas.

In the invention according to the sixth aspect, by constantly supplying an inert gas to the heating space, impurities such as moisture which inhibits the reduction reaction are released from the system without staying in the heating space. Therefore, the reduction rate is improved.

According to a seventh aspect of the present invention, in the actinide oxide reducing device according to the third aspect, instead of the reducing agent introduction hole, the through-path is connected to one of the collection container and the holding container. And a thermocouple insertion hole into which a thermocouple is inserted.

In the invention according to claim 7, since the thermocouple can be always inserted, the temperature of the molten salt can be accurately grasped, and a temperature change or the like that hinders the reduction reaction is prevented. be able to.

According to an eighth aspect of the present invention, in the apparatus for reducing actinide oxide according to any one of the third to seventh aspects, a stopper for closing the through passage is provided.

According to the present invention, the heat dissipation for heating the heating space is suppressed low by closing the through passage with a stopper and suppressing heat radiation from the heating space to the room temperature space. A healthy working environment can be ensured by avoiding a rise in space temperature.

According to a ninth aspect of the present invention, in the actinide oxide reducing device according to the first aspect, the stirring device is provided with a rotatable stirring blade.

According to the ninth aspect of the present invention, the actinide oxide in the molten salt by the rotational movement of the stirring blade, a reducing agent for reducing the actinide oxide, and an oxide of the reducing agent generated after reducing the actinide oxide By promoting the diffusion of, the reduction reaction proceeds without delay and the reduction rate is improved.

According to a tenth aspect of the present invention, in the actinide oxide reducing apparatus according to the ninth aspect, the stirring blade is attached to a shaft portion, and the shaft portion is used in a state of use in comparison with a portion immersed in a molten salt. It is characterized in that it can be separated upward.

According to the tenth aspect of the present invention, even if a problem occurs in the stirring blade, it is not necessary to replace the entire stirring device, and only the stirring blade needs to be replaced, so that the amount of waste can be reduced. Further, since the divided portion of the stirring blade is not immersed in the molten salt, the divided portion is not fixed by the molten salt, and is easily removed at the time of replacement.

According to an eleventh aspect of the present invention, in the actinide oxide reducing device according to the ninth or tenth aspect, the stirring device is configured to be separable into a driving unit, a shaft unit, and a stirring blade. I do.

According to the eleventh aspect of the present invention, when a problem occurs in a part of the stirrer, the part is replaced while a healthy part is reused as it is. Separation and assembly can be arbitrarily performed accordingly, so that operability is improved.

In the invention according to claim 12, in the apparatus for reducing actinide oxide according to claim 10 or 11,
The shaft portion is supported at two upper and lower positions.

In the twelfth aspect of the present invention, the rigidity of the shaft portion is improved by supporting the shaft portion at two upper and lower portions, and the stirring blade can be rotated at a higher speed. Remarkably appears, and the reduction rate can be improved.

According to a thirteenth aspect of the present invention, in the apparatus for reducing an actinide oxide according to any one of the first to fifth aspects, the extension of the through-path is formed by a stirring blade of the stirring device and an inner wall of the collection container. And is located in a gap between them.

In the thirteenth aspect of the present invention, the reducing agent and the actinide oxide are first brought into direct contact with the molten salt at the time of loading into the salt, whereby the stirring effect is improved, and the reducing agent and the actinide oxide can be arbitrarily selected during operation of the sample. By sampling at an arbitrary salt height for a time, the progress of the reduction reaction in the molten salt can be accurately grasped. Further, it is possible to avoid interference or collision between the loaded substance or the measuring instrument and the rotating body of the stirring device.

According to a fourteenth aspect of the present invention, in the actinide oxide reducing device according to the first aspect, a thermocouple insertion pipe for inserting a thermocouple is provided between the holding container and the recovery container. And

In the fourteenth aspect of the present invention, the thermocouple does not contact or become entangled with the stirring blade.
The molten salt temperature can be measured stably.

According to a fifteenth aspect of the present invention, in the actinide oxide reducing device according to the first aspect, the holding container has a height for holding a salt before melting.

In the invention according to the fifteenth aspect, since a large salt before melting can be retained, a required amount of salt can be melted at a time, and the operation time and labor can be reduced. it can.

According to a sixteenth aspect of the present invention, in the actinide oxide reducing device according to the first aspect, the holding container is formed to be thin.

In the invention according to claim 16, when the molten salt is recovered after solidification of the molten salt, the molten salt is fixed to the holding container, so the holding container must be destroyed to recover the molten salt. However, at this time, since the holding container is formed to be thin, destruction is facilitated and recovery of the molten salt is facilitated.

In the invention according to claim 17, in the apparatus for reducing actinide oxide according to claim 15 or 16,
The holding container is smaller than the bulk of the salt before melting, and a main body container having a volume for holding the solidified salt after melting,
An auxiliary container is detachably connected to an upper portion of the main container and extends to a height for holding a salt before melting.

In the invention according to claim 17, when the operation is completed and the used salt after cooling is recovered, the main container storing the salt is discarded, and the auxiliary container is separated from the main container and reused. This can reduce the volume of waste.

According to an eighteenth aspect of the present invention, in the actinide oxide reducing device according to the seventeenth aspect, the connecting portion of the holding container is provided intermittently in a circumferential direction.

According to the eighteenth aspect of the present invention, since the joining portion is provided intermittently in the circumferential direction, the amount of adhered molten salt is small, and the separation of the main container and the auxiliary container is facilitated.

In the invention according to claim 19, in the actinide oxide reducing device according to claim 1, when the operation for reducing the actinide oxide is stopped, the recovery is performed while the holding container is installed in the heating space. A container is held above the liquid level of the molten salt so as to be separable from the salt phase.

In the invention according to the nineteenth aspect, the salt attached to the metal actinide in the recovery container in a state in which the salt is molten is removed under natural flow, cooled while maintaining the molten salt on the liquid surface, and then recovered. Can be taken out, so that a healthy working environment for the collection operation can be secured.

According to a twentieth aspect of the invention, in the apparatus for reducing an actinide oxide according to the first or the ninth aspect, the separating means is a mesh, and the mesh is provided at the bottom of the recovery container. I do.

In the twentieth aspect of the present invention, when the recovery container is pulled up, the liquid substance such as the molten salt passes through the mesh and remains in the holding container, so that only the solid reduction product (actinide metal) is formed. Can be selectively recovered.

According to a twenty-first aspect of the present invention, in the actinide oxide reducing device according to the first or twentieth aspect, the bottom surface of the recovery container is configured to be in contact with the bottom surface of the holding container. .

The invention according to claim 21 eliminates the concern that the stirring effect is reduced by the actinide oxide that has passed through the mesh of the collection container and deposited in the gap between the bottoms of both the collection container and the holding container, Actinide oxide can be reduced evenly.

According to a twenty-second aspect of the present invention, in the actinide oxide reducing device according to the twentieth aspect, the bottom plate of the recovery container is configured to be removable.

In the invention according to claim 22, since the reduced product (actinide metal) is accumulated at the bottom of the recovery container, even if a small amount of the molten salt remains or even if it is fixed to the bottom, The removal of the bottom product is facilitated by making the bottom plate removable.

According to a twenty-third aspect of the present invention, in the actinide oxide reducing device according to the twentieth aspect, the collecting container is provided with a baffle plate on an inner wall surface.

According to the twenty-third aspect of the present invention, by providing the baffle plate, the stirring efficiency is improved and a high reduction rate can be obtained.

According to a twenty-fourth aspect of the present invention, in the actinide oxide reduction device according to the first aspect, the recovery container is constituted by an inner and outer double cylindrical container, the inner container is removable, and the outer container is A slit is formed from a position at a predetermined height from the bottom, and a lower end of the inner container is separated from a bottom of the outer container.

In the invention according to claim 24, the distance between the end of the slit and the bottom plate is set to a distance commensurate with the volume of the liquid reduction product. It is possible to selectively recover only the reduced product in the form.

According to a twenty-fifth aspect of the present invention, in the actinide oxide reducing device according to the twenty-fourth aspect, the bottom plate of the outer container is configured to be removable.

According to the twenty-fifth aspect of the present invention, the reduced product (actinide metal) accumulates at the bottom of the recovery container. Therefore, even if a small amount of molten salt remains, it is fixed to the bottom and difficult to recover. However, the removal of the reduced product is facilitated by making the bottom surface removable.

According to a twenty-sixth aspect of the present invention, in the actinide oxide reducing device according to the twenty-fourth aspect, a baffle plate is provided on an inner wall of the inner container.

According to the twenty-sixth aspect of the present invention, the provision of the baffle plate improves the stirring efficiency and enables a high reduction rate to be obtained.

According to a twenty-seventh aspect, in the actinide oxide reducing device according to the twenty-fourth aspect, a mesh is provided on a bottom surface of the inner container.

According to the twenty-seventh aspect of the present invention, when the recovery container is pulled up, a liquid substance such as a molten salt passes through the mesh and remains in the holding container, so that only a solid reduction product (actinide metal) is formed. Can be selectively recovered.

According to a twenty-eighth aspect of the present invention, in the actinide oxide reducing device according to the twenty-seventh aspect, the bottom plate of the inner container is configured to be removable.

According to the twenty-eighth aspect of the present invention, since the bottom plate can be removed, recovery of the reduced product is facilitated.

According to a twenty-ninth aspect of the present invention, in the actinide oxide reducing device according to the twenty-seventh aspect, a baffle plate is provided on an inner wall of the inner container.

In the invention according to claim 29, by providing the baffle plate, the stirring efficiency is improved, and a high reduction rate can be obtained.

[0067]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a longitudinal sectional view showing a first embodiment of an actinide oxide reduction device according to the present invention. Parts that are the same as or correspond to the conventional configuration will be described using the same reference numerals as in FIG.

In FIG. 1, the actinide oxide reduction device of the present embodiment is formed in a cylindrical shape with a bottom and is formed of Licl or L.
Holding container 5 containing molten salt 2 such as icl-Kcl
And recovery, which is installed inside the holding container 5 and immersed in the molten salt 2, and is added with an actinide oxide 3 such as uranium oxide (UO ₂ ) and a reducing agent 4 such as Li or Mg for reducing the same. Container 6 and reducing agent 4 in molten salt 1
A stirrer 7 for diffusing the actinide oxide 3 and a heating device 8 formed in a cylindrical shape and provided with a heater therein for heating the molten salt 2 and the reducing agent 4 are provided.

The recovery container 6 is provided with a separation means such as a mesh or a slit for separating the molten salt 2 from a reduction product such as uranium (U) after the completion of the reduction reaction. Therefore, the molten salt 2 and the like can flow between the holding container 5 and the collection container 6 through the mesh or the slit.

In the reduction device of this embodiment, the drive motor 9 is installed at room temperature, and the drive shaft 9 a of the drive motor 9 is connected to one end of the flexible shaft 11 via the coupling 10. 11
Is connected to the upper end of the shaft section 15 via a coupling section 14 and a fixing section 13 fixed to the support base 12. At the lower end of the shaft portion 15, a stirring blade 16 as a stirring means composed of four blades constituting the stirring device 7 is attached, and the stirring blade 16 is immersed in the molten salt 2 in the collection container 6. I have.

The support base 12 is fixed to a mounting flange 17, and the mounting flange 17 is fixed on a support flange 18. A guide block 20 is fixed to the support flange 18 via a plurality of mounting rods 19. A support pipe 21 for supporting the shaft portion 15 is inserted through the guide block 20 and the mounting flange 17, and is supported by the mounting flange 17. ing. The support pipe 21 includes upper and lower support portions 22a, 22b with respect to the axial direction of the shaft portion 15.
Supports the shaft portion 15.

Therefore, when the drive motor 9 is driven, its drive shaft 9a rotates to transmit its rotational force to the shaft portion 15 via the coupling 10, the flexible shaft 11 and the coupling 14 to rotate it. Then, the stirring blade 16 rotates to diffuse the actinide oxide 3 and the reducing agent 4 into the molten salt 2.

Further, in the reduction device of this embodiment, the temperature of the molten salt 2 is maintained at 550 to 700 ° C. by the heating device 8, while the rotation speed of the stirring blade 16 is 500 to 1200.
rpm. Then, 10 mol of Licl is contained in the molten salt 2 of the present embodiment, 0.1 mol of UO ₂ is contained in the actinide oxide 3, and 0.4 mol is contained in the reducing agent 4.
The above Li is used respectively.

Next, the operation of the present embodiment will be described.

In the present embodiment thus configured, in the argon gas atmosphere, Licl as the molten salt 2 is accommodated in the holding vessel 5 and heated to 550 to 700 ° C. UO ₂ that is object 3
After immersion, the reduction reaction of UO ₂ + 4Li → U + 2Li ₂ O proceeds by introducing Li as the reducing agent 4.

Here, the molten salt 2 and the reducing agent 4 are maintained in a molten state by the heating device 8. And the stirring device 7
By stirring the inside of the recovery container 6 with the actinide oxide 3, the reducing agent 4, the actinide oxide 4 in the molten salt 1,
Can reduce the diffusion of the reducing agent oxide (2Li ₂ O) generated after the reduction. The actinide metal (U), which is a reduction product after the completion of the reduction reaction, and the molten salt 2 are:
It is separated by the collection container 6.

As described above, according to the present embodiment, the molten salt 1 and the reducing agent 4 are maintained in a molten state by the heating device 8,
The reducing agent 4 in the molten salt 2 is suspended in the molten salt 2 by suspending the reducing agent 4 in the molten salt 2 by the stirrer 7 and simultaneously suspending the powder or solid actinide oxide 3 in the molten salt 2.
Can be maintained, the contact efficiency between the powder or solid actinide oxide 3 and the reducing agent 4 is promoted, and the reduction rate can be improved.

Further, by stripping the reducing agent oxide from the actinide oxide 3, the reducing agent oxide adheres to the surface of the actinide oxide 3, and a new unreacted reducing agent 4 is added to the actinide oxide 3. A high reduction rate can be obtained because it is possible to prevent the reduction rate from deteriorating by inhibiting the contact with.

Further, since the recovery vessel 6 has a separation means for separating the actinide metal (reduction product) after the completion of the reduction reaction and the molten salt 2, the recovery product U
Can be selectively recovered.

[Second Embodiment] FIG. 2 is a longitudinal sectional view showing a second embodiment of the actinide oxide reduction device according to the present invention. In the second and subsequent embodiments, only portions different from the first embodiment in configuration, operation, and effects will be described, and the same portions as those in the first embodiment will be denoted by the same reference numerals and description thereof. Omitted.

In FIG. 2, in the present embodiment, a heat shield layer 25 is fixed to the lower surface of the mounting flange 17, and the lower part of the heat shield layer 25 is arranged in the opening of the guide block 20. The heat shielding layer 25 thermally shields a space at a constant temperature equal to or higher than the melting point and a space near room temperature in order to adjust the molten salt 2.

In the present embodiment configured as described above,
The upper part of the heat shielding layer 25 must be kept close to room temperature for operations involving human access such as operating temperature conditions of the stirrer 7 and maintenance and inspection thereof, and handling operations of the actinide oxide 3 and the reducing agent 4. . On the other hand, in the lower part of the heat shield layer 25, it is necessary to maintain the temperature in a high temperature region exceeding the melting point of the salt. In the present embodiment, however, the space between the heating space below the heat shield layer 25 and the room temperature space above the heat shield layer 25 is required. By blocking heat in and out by the heat shielding layer 25, a temperature rise in the room temperature space is avoided and a sound working environment is secured.

As described above, according to the present embodiment, the heat shielding layer 25 blocks heat from flowing into and out of the heating space and the room temperature space, thereby realizing a necessary temperature environment, and
This makes it possible to reduce the amount of heat consumed.

Third Embodiment Next, a third embodiment of the actinide oxide reduction device according to the present invention will be described with reference to FIG. FIG. 3 is a longitudinal sectional view showing third to seventh embodiments of the actinide oxide reduction device according to the present invention.

Referring to FIG. 3, this embodiment is different from the second embodiment in the structure of the second embodiment.
6 is provided, and the reducing agent 4 can be directly charged into the collection container 6 from the through pipe 26.

In the present embodiment configured as described above, the through-passage extending from the upper surface of the reduction device to the collection container 6 is formed by the through pipe 26, so that the reducing agent 4 can be charged at any time even during the reduction reaction. .

As described above, according to the present embodiment, the through pipe 26 penetrating the heat shielding layer 25 from the upper surface of the reduction device and facing the inside of the collection container 6 is provided, and the reducing agent 4 can be injected into the collection container 6 at any time. As a result, the concentration of the reducing agent 5 can be maintained at a concentration suitable for the reduction reaction without running out of the reducing agent 5, so that a high reduction rate can be obtained. In addition, since the reduction reaction can be performed continuously, the operation efficiency of the apparatus can be improved.

Fourth Embodiment Next, a fourth embodiment of the actinide oxide reduction device according to the present invention will be described with reference to FIG.

In FIG. 3, this embodiment is different from the second embodiment in the structure of the second embodiment. In addition, the through pipe 2 penetrates through the heat shielding layer 25 from the upper surface of the reduction apparatus and faces the inside of the recovery container 6.
A through hole of the through pipe 26 is used as a sampling hole for directly collecting a sample from the inside of the collection container 6.

In the present embodiment configured as described above, a through pipe 26 is provided from the upper surface of the apparatus to the collection container 6, and the molten salt 2 in the collection container 6 is sampled as needed from the through hole of the through pipe 26. It is possible to do.

Therefore, in this embodiment, by taking a sample during the reduction reaction, the molten salt 2, the actinide oxide 3, the reducing agent 4 for reducing the same, and the actinide oxide 2 during operation are produced by reduction. The state of the reducing agent oxide generated after reducing the metal actinide and actinide oxide 3 to be reduced.

As described above, according to the present embodiment, since the through pipe 26 penetrating the heat shielding layer 25 from the upper surface of the reduction device is provided, the inside of the collection vessel 6 is reduced from the through hole of the through pipe 26 during the reduction reaction. Can be collected as a sample at any time, so that the state of the molten salt 2 during the reduction reaction can be monitored. Thereby, a state suitable for the reduction reaction can be maintained, and a high reduction rate can be obtained.

[Fifth Embodiment] Next, a fifth embodiment of the actinide oxide reduction device according to the present invention will be described with reference to FIG.

In FIG. 3, in addition to the structure of the reduction device of the second embodiment, this embodiment has a penetration pipe 26 that penetrates the heat shielding layer 25 from the upper surface of the reduction device and faces the collection container 6.
The through-hole of the through pipe 26 is used as an actinide oxide charging hole for loading the actinide oxide 3 in the collection container 6.

In the present embodiment thus configured, a through pipe 26 is provided from the upper surface of the apparatus to the recovery container 6, and the actinide oxide 3 is loaded into the recovery container 6 from the through hole of the through pipe 26 as needed. be able to. Therefore, by directly loading the actinide oxide 3 into the molten salt, it is not necessary to load the salt before melting and the actinide oxide 3 at the same time, and impurities generated from the actinide oxide 3 in the process of melting the salt are reduced. Avoid the problem of adsorption to salt.

As described above, according to the present embodiment, since the through pipe 26 penetrating the heat shielding layer 25 from the upper surface of the reduction device and facing the collection container 6 is provided, the reduction reaction from the through hole of the through pipe 26 is performed. The actinide oxide 3 can be loaded into the collection container 6 at any time. As a result, since the actinide oxide 3 can be loaded even after the salt is melted, the salt can be melted alone before the actinide oxide 4 is loaded.

The salt easily adsorbs impurities as a solid,
Since it is very difficult to remove the adsorbed impurities, if the impurities are contaminated before melting, the impurities remain in the salt even after the melting to inhibit the reduction reaction and deteriorate the reduction rate. Therefore, by melting the salt alone, it is possible to provide a high purity molten salt 2 which is not affected by impurities of the actinide oxide 3, and it is possible to improve the reduction rate.

[Sixth Embodiment] Next, a sixth embodiment of the actinide oxide reduction device according to the present invention will be described with reference to FIG.

Referring to FIG. 3, this embodiment is different from the second embodiment in the structure of the second embodiment.
The through hole of the through pipe 26 is used as an inert gas supply pipe insertion hole and an inert gas discharge pipe insertion hole for supplying and discharging an inert gas such as an argon gas into the collection container 6. ing.

In the present embodiment configured as described above, the through pipe 26 that penetrates the heat shielding layer 25 from the upper surface of the reduction device and faces the recovery container 6 is provided. The inert gas can be constantly supplied into the heating space, and the inert gas can be discharged from the heating space.

As described above, according to the embodiment, by using the through-hole of the through pipe 26 as the inert gas supply pipe, the inert gas can be constantly supplied into the heating space, and the heating space can be efficiently used. Since replacement with an active gas can be performed, oxidizing gas or moisture that hinders the reduction reaction can be excluded, and an atmosphere suitable for the reduction reaction can be maintained, and a high reduction rate can be obtained. be able to.

Further, since the through hole of the through pipe 26 is used as an inert gas discharge pipe for releasing the rising pressure of the heating space due to the continuous supply of the inert gas to the outside of the system, an abnormal inside of the heating space is required. There is no pressure increase and the like, and the soundness of the device can be maintained.

[Seventh Embodiment] Next, a seventh embodiment of the actinide oxide reduction device according to the present invention will be described with reference to FIG.

In FIG. 3, this embodiment is different from the second embodiment in the structure of the second embodiment.
6 is provided, and the through hole of the through pipe 26 is used as a thermocouple insertion hole into which a thermocouple can be directly inserted into the collection container 3.

In the present embodiment configured as described above, the through pipe 26 penetrating the heat shielding layer 25 from the upper surface of the reduction device and facing the recovery container 6 is provided. It is possible to always insert a thermocouple. Therefore, since the temperature of the molten salt 2 can be accurately grasped by always inserting a thermocouple, it is possible to prevent a temperature change that hinders the reduction reaction.

As described above, according to the present embodiment, accurate temperature control becomes possible by always inserting a thermocouple, so that the temperature of the molten salt 2 and the reducing agent 4 is maintained at a temperature suitable for reduction. And a high reduction rate can be obtained.

[Eighth Embodiment] FIG. 4 is a longitudinal sectional view showing an actinide oxide reducing apparatus according to an eighth embodiment of the present invention.

In FIG. 4, this embodiment is different from the reduction apparatus of the third to seventh embodiments in that the reduction apparatus described in the third to seventh embodiments penetrates through the heat shielding layer 25 from the upper surface and faces the collection container 6. The through hole of the pipe 26 can be closed by a stopper 27.

In the present embodiment configured as described above, when the through-hole of the through pipe 26 is used as an inert gas supply pipe insertion hole, an inert gas discharge pipe insertion hole, and a thermocouple insertion hole, it is always used. When used as sampling holes and actinide oxide charging holes, they are not used even during operation, so they are closed with the stopper 27 to maintain a healthy temperature environment between the heating space and the room temperature space.

That is, in this embodiment, the penetration pipe 2
By closing the through hole of 6 with the closing plug 27, heat radiation from the heating space to the room temperature space is suppressed, the amount of heat consumed for heating the heating space is kept low, and the temperature rise in the room temperature space is avoided to ensure sound work. The environment is secured.

As described above, according to the present embodiment, the stopper 2
By closing the through hole of the through pipe 26 with 7, a healthy temperature environment of the heating space and the room temperature space can be maintained. As a result, the heat consumption of the heating device 8 is suppressed, the accident in which the stirring device 7 is broken due to the deviation from the operating temperature condition in the room temperature space is prevented, the human access is enabled, and the accuracy of the maintenance work is improved. Can be improved.

[Ninth Embodiment] FIG. 5 is a longitudinal sectional view showing a ninth embodiment of the apparatus for reducing actinide oxide according to the present invention.

In FIG. 5, the present embodiment is configured such that the shaft portion 15 described in the first embodiment can be separated at a divided portion 28 above a portion immersed in the molten salt 2 in a use state.

In this embodiment, the stirring device 7 includes the shaft portion 15, the stirring blade 16 and the driving portion 30. The drive unit 30 includes a drive motor 9, a coupling 10, a flexible shaft 11, a coupling 14, and the like.

Further, in the present embodiment, the shaft portion 15 is supported at two places: a support portion 22a near the working plane and a support portion 22b near the molten salt 2 liquid level.

In the present embodiment configured as above, the shaft portion 15 is separable from the stirring blade 16 at the dividing portion 28, and the dividing portion 28 is separated from the molten salt 2 even when the stirring device 7 is in use. Is provided above the liquid level of the molten salt 2 so as not to be immersed.

Further, since the stirring device 7 is composed of the shaft portion 15, the stirring blade 16 and the driving portion 30, the stirring device 7 is separated and assembled as required and used repeatedly.

Further, the shaft 15 is supported by the support 22a.
And the support part 22b is supported at two places above and below,
The rigidity of the shaft portion 15 increases, and the natural frequency of the rotating portion increases.

As described above, according to the present embodiment, since the shaft portion 15 is separable from the stirring blade 16, the stirring device 7 can be operated even when the stirring blade 16 is defective.
It is not necessary to replace the whole, only the stirring blade 16 needs to be replaced, so that the amount of waste can be reduced. Also,
Since the divided portion 28 is not immersed in the molten salt 2, the divided portion 28 is not fixed by the molten salt 2, and is easily removed at the time of replacement.

Further, according to the present embodiment, the shaft 1
5. If any of the components of the stirring blade 16 or the drive unit 30 is defective, the volume of the waste can be reduced by replacing the component and reusing the other component. And
Separation makes it possible to reduce the size and weight, so that the handling operation can be simplified and labor can be saved. Further, separation and assembly can be arbitrarily performed according to the situation, so that operability can be improved.

Further, according to the present embodiment, the rigidity of the shaft portion 15 is improved by supporting the shaft portion 15 up and down, and the stirring blade 16 can be rotated at a higher speed. Remarkably appears, and the reduction rate can be improved.

[Tenth Embodiment] FIG. 6 is a longitudinal sectional view showing an actinide oxide reducing device according to a tenth embodiment of the present invention.

In FIG. 6, in the present embodiment, the extension line 31 of the through pipe 26 used for the reducing agent introduction hole, the sampling hole, the actinide oxide introduction hole, and the thermocouple insertion hole is different from the stirring blade 16 and the inner wall of the collection vessel 6. Is configured to be located in the gap between the two.

That is, when the orbit of the communication hole between the room temperature space and the heating space is extended to the heating space, the stirring blade 16
In the present embodiment configured as described above, the actinide oxide 4 and the reducing agent 5 are initially structured at the time of charging. It is loaded in the heating space so as to directly contact the molten salt 2 without touching the material. Also, at the time of sampling and temperature monitoring, the sampling jig and the thermocouple do not interfere with the structural material in the heating space.

As described above, according to the present embodiment, since the actinide oxide 3 and the reducing agent 4 are prevented from remaining outside the molten salt 2, an efficient reduction step can be performed. In particular,
For example, when the reducing agent 4 is metallic lithium and the material of the structural material is a combination of stainless steel, the metallic lithium has a property of easily attaching to the stainless steel. When contacted with stainless steel, the metallic lithium stays at the position where it has adhered and becomes less likely to be used for the reduction of actinide oxide 3,
This is an effective means for improving the reduction rate.

That is, the actinide oxide 3, the reducing agent 4
When the powder is loaded into the salt, it first comes into direct contact with the molten salt 2 so that the stirring effect can be improved.

Further, the sampling and temperature monitoring can be carried out at any time during the operation and at an arbitrary salt height and measured, so that the progress of the reduction reaction in the molten salt 2 can be accurately grasped. it can. Further, since the actinide oxide 3, reducing agent 4, sampling jig and thermocouple to be loaded or inserted do not interfere with or collide with the rotating body of the stirrer 7, damage accidents can be avoided beforehand. it can.

[Eleventh Embodiment] FIG. 7 is a longitudinal sectional view showing an eleventh embodiment of the apparatus for reducing actinide oxide according to the present invention.

In FIG. 7, the present embodiment shows a thermocouple insertion pipe 32 for inserting a thermocouple into the support flange 18.
Is supported, and the other end of the thermocouple insertion pipe 32 is supported by the guide block 20. The extension line 33 at the tip of the thermocouple insertion pipe 32 faces the molten salt 2 between the holding container 5 and the recovery container 6.

In the present embodiment thus constructed, the thermocouple is inserted from the upper surface of the apparatus, and the molten salt 2 between the holding container 5 and the recovery container 6 is extended along the thermocouple insertion pipe 32 and the extension 33 thereof. Inserted inside.

As described above, according to the present embodiment, since the thermocouple is inserted between the holding container 5 and the recovery container 6, the thermocouple does not come into contact with or entangle with the stirring blade 16, and Breakage of the pair and the stirring blade 16 can be prevented, and the temperature of the molten salt 2 can be stably measured.

[Twelfth Embodiment] FIG. 8 is a longitudinal sectional perspective view showing a main part of a twelfth embodiment of the actinide oxide reduction device according to the present invention.

In FIG. 8, the present embodiment is similar to the holding container 5 shown in FIG.
Is set higher than the height H1 of the salt before melting. That is, the holding container 5 has a height that can hold the salt before melting.

In the present embodiment thus configured, the molten salt 2 is smaller in bulk than before melting, so that the height H2 of the salt after melting is lower than the height H1 of the salt before melting. In the embodiment, the holding container 5 has a volume for holding a salt before melting which has a large bulk in advance.

As described above, according to the present embodiment, a large amount of salt before melting can be retained, so that a required amount of salt can be melted at a time, thereby reducing the operation time and labor. be able to. Further, the holding container 5
Can hold the molten salt 2 in a stationary state, but the liquid level of the molten salt 2 becomes mortar-shaped by stirring, and the holding container 5
There is also the effect that the liquid level rises or scatters at the periphery of the, so by setting the height to hold the salt before melting,
Leakage of the molten salt 2 out of the holding container 5 is eliminated. In addition,
Even if a small amount of the molten salt 2 leaks and solidifies by cooling, sticking is remarkable and handling becomes complicated. Therefore, by preventing the leakage, the work can be rationalized and labor can be saved.

[Thirteenth Embodiment] FIG. 9 is a longitudinal sectional perspective view showing a main part of a thirteenth embodiment of the actinide oxide reducing device according to the present invention.

In FIG. 9, in the present embodiment, the entire bottomed cylindrical holding container 5 is formed to be thin.

In the present embodiment having the above-described structure, the holding container 5 is formed thin, so that the holding container 5 can be easily broken.

When the molten salt 2 is recovered after solidification of the molten salt 2, the molten salt 2 is fixed to the holding container 5, so it is necessary to destroy the holding container 5 and recover the molten salt 2. At this time, since the holding container 5 is formed to be thin, it is easily broken, and the recovery of the molten salt 2 becomes easy.

As described above, according to the present embodiment, since the holding container 5 can be easily broken, the time for coagulating and recovering the molten salt 2 can be reduced, and the operation efficiency of the apparatus can be improved. it can.

[Fourteenth Embodiment] FIGS. 10A and 10B
FIG. 19 is a longitudinal sectional perspective view showing a main part of a fourteenth embodiment of the actinide oxide reducing device according to the present invention, and is an enlarged view of a part A in FIG.

In FIGS. 10 (A) and 10 (B), in this embodiment, the holding container 5 comprises a bottomed cylindrical main body container 5a and a cylindrical auxiliary container 5b, and the main body container 5a and the auxiliary container 5b Are fitted at the connection portion 35 and can be vertically divided.

That is, in the present embodiment, a main container 5a having a volume smaller than the bulk of the salt before melting but capable of holding the molten salt 2 and the solidified salt after the melting, and the upper portion of the main container 5a The main container 5a and the auxiliary container 5b are configured to be separable at the connecting portion 35 by integrating with the auxiliary container 5b extending to a height capable of holding the previous salt.

In this embodiment, the main container 5a holds the molten salt 2 but does not fill the volume of the salt before melting.
a to hold the salt before melting.

As described above, according to the present embodiment, when the salt is collected and discarded after the operation is completed, only the main container 5a is discarded, and the auxiliary container 5b is reused to reduce the volume of the waste. it can.

[Fifteenth Embodiment] FIG. 11 is a longitudinal sectional perspective view showing a main part of a fifteenth embodiment of the actinide oxide reducing device according to the present invention.

In FIG. 11, in the present embodiment, the joining portion 37 between the main container 5a and the auxiliary container 5b of the holding container 5 is intermittent at a predetermined interval, and the other portions are the first portion.
It comprises the same components as in the fourth embodiment.

In the present embodiment thus configured, the connection portion 37 of the holding container 5 is intermittent, so that the amount of the molten salt 2 fixed can be reduced, and the main container 5a and the auxiliary container 5b And separation becomes easy.

As described above, according to the present embodiment, the amount of the molten salt 2 adhered to the connection portion 37 of the holding container 5 is small, so that the time required for dividing the holding container 5 can be reduced, and the operation of the apparatus can be reduced. Efficiency can be improved.

[Sixteenth Embodiment] FIG. 12 is a longitudinal sectional view showing a sixteenth embodiment of the actinide oxide reduction device according to the present invention.

FIG. 12 shows a configuration of the present embodiment when the recovery container 6 is separated from the molten salt 2 in the holding container 5 in the heating space. That is, when the operation of the recovery container 6 is stopped to reduce the actinide oxide 3, the recovery container 6 is configured to be retained above the liquid level of the molten salt 2 and separated from the salt phase while being installed in the heating space. .

In the present embodiment configured as above, the metal actinide generated from the actinide oxide 3 collected in the collection container 6 and the salt attached to the metal actinide were kept separated at the melting point or higher, and cooled. Thereafter, the collection container 6 is taken out into the room temperature space and the collection operation is performed. That is, in the present embodiment, the salt attached to the metal actinide in the recovery container 6 in a state where the salt is molten is removed under a natural flow, and after cooling while keeping the molten salt 2 on the liquid surface, the recovery container 6 is cooled. Since it can be taken out, a healthy working environment for the collection work can be secured.

As described above, according to the present embodiment, since the salt can be separated as a liquid, the salt can be efficiently removed from the metal actinide, and the collection container 6 can be taken out after cooling the heating space. Since it is possible, the collection operation can be performed at a healthy temperature, and as a result, safety can be ensured.

[Seventeenth Embodiment] FIG. 13 is a longitudinal sectional perspective view showing a main part of a seventeenth embodiment of the actinide oxide reduction device according to the present invention.

In FIG. 13, a mesh (net) 39 as a separating means is attached to the bottom of the collection container 6 in this embodiment.

In the present embodiment having the above-described structure, the mesh 39 is provided at the bottom of the collection container 6, so that when the collection container 6 is pulled up, the liquid substance such as the molten salt 2 passes through the mesh 39. , Fall into the holding container 5, and the solid reduction product (actinide metal) remains on the mesh 39 at the reduction reaction temperature.

As described above, according to the present embodiment, when the recovery container 6 is pulled up, only the solid reduction product remains on the mesh 39 at the reduction reaction temperature. Can be selectively recovered.

[Eighteenth Embodiment] FIG. 14 is a longitudinal sectional perspective view showing a main part of an eighteenth embodiment of the actinide oxide reducing device according to the present invention.

In FIG. 14, the present embodiment is configured such that the bottom surface of the collection container 6 is in contact with the bottom surface 41 of the holding container 5.

In the present embodiment configured as described above, since the bottom surface of the collection container 6 is in contact with the bottom surface 41 of the holding container 5, even a fine actinide oxide that passes through the mesh 39 can be used. Does not settle at the bottom.

When the actinide oxide 3 is deposited in the gap between the mesh 39 and the bottom surface 41 of the holding container 5, the mesh 39
Is not sufficiently reduced because it becomes an obstacle and stays during stirring. Therefore, according to the present embodiment, the actinide oxide 3 can be uniformly stirred without retaining the actinide oxide 3 to improve the reduction rate.

[Nineteenth Embodiment] FIG. 15 is a longitudinal sectional perspective view showing a main part of a nineteenth embodiment of the actinide oxide reduction device according to the present invention.

In FIG. 15, in the present embodiment, the bottom plate 43 of the collection container 6 is configured to be removable. Other components are the same as those of the eighteenth embodiment.

In the present embodiment having the above-described structure, the collection container 6 has a structure in which the bottom plate 43 can be removed. Therefore, the reduction product (actinide metal)
Since the molten salt 2 remains at the bottom of the recovery container 6, even if the molten salt 2 remains even in a small amount and solidifies at the bottom, the bottom plate 43 can be removed, so that the reduction product can be easily recovered.

As described above, according to the present embodiment, since the recovery container 6 has a structure in which the bottom plate 43 is removable, when the recovery container 6 is pulled up to collect the reduction product after the completion of the reduction reaction, The material is stored at the bottom of the recovery container 6, and the molten salt 2 remaining on the surface of the reduction product solidifies,
Even when the reduction product and the recovery container 6 are fixed, the reduction product can be easily recovered by removing the bottom plate 43.

[Twentieth Embodiment] FIG. 16 is a longitudinal sectional perspective view showing a main part of a twentieth embodiment of the actinide oxide reduction device according to the present invention.

In FIG. 16, in the present embodiment, a plurality of baffle plates 45 formed in a rectangular shape along the longitudinal direction of the collection container 6 are radially provided on the inner surface of the collection container 6.

In the present embodiment configured as described above, the stirring efficiency is improved by a plurality of baffles 45 radially provided on the inner surface of the collection container 6.

As described above, according to this embodiment, since the stirring efficiency is improved, the operation time is shortened, and the reduction rate can be improved.

[Twenty-first Embodiment] FIG. 17 is a longitudinal sectional perspective view showing a main part of a twenty-first embodiment of an actinide oxide reduction device according to the present invention.

In FIG. 17, in the present embodiment, the collection container 6 is a double cylindrical container, and the inner container 6a is configured to be removable, while the outer container 6b has a predetermined height from the bottom in the circumferential direction. Slit 4 as separation means from the position
7 are formed, and the lower end of the inner container 6a and the bottom of the outer container 6b are installed so as not to be in close contact with each other.

In the present embodiment thus configured, the recovery container 6 is a double cylindrical container, and a slit is formed above the bottom of the outer container 6b at a position corresponding to the volume corresponding to the volume of the liquid reduction product. While a plurality of 47 are formed, the inner container 6a has a structure separable from the outer container 6b, and is provided with a slight gap between the lower end portion of the inner container 6a and the bottom surface of the outer container 6b so that the molten salt 2 can pass through. Have been.

Thus, during the reduction reaction, the powdered actinide oxide 3 can be prevented from being scattered outside the range where the stirring effect is exerted, that is, outside the inner container, by the stirring operation of the stirring device 7, After the completion of the reaction, the collection container 6
Is lifted above the liquid level of the molten salt 2 and the inner container 6a is removed, so that the liquid reduced product having a large specific gravity accumulates below the lower end of the slit 47 of the outer container 6b, and the molten salt 2 having a small specific gravity is removed. Is discharged from the slit 47 to the outside of the outer container 6b.

As described above, according to the present embodiment, the powdered actinide oxide 3 can be prevented from scattering during the reduction reaction, and only the salt can be discharged out of the recovery container 6 after the reduction reaction. A high reduction rate can be obtained, and a liquid reduction product can be selectively recovered.

[Twenty-second Embodiment] FIG. 18 is a longitudinal sectional perspective view showing a main part of a twenty-second embodiment of the actinide oxide reducing device according to the present invention.

In FIG. 18, the present embodiment is the same as the second embodiment.
In addition to the configuration of the first embodiment, an outer container 6b of a double cylindrical container
The bottom plate 43 is configured to be removable.

In the present embodiment configured as above, the bottom plate 43 is removed and the actinide oxide 3 and metal actinide deposited on the bottom are collected. Since the reduced product (actinide metal) accumulates at the bottom of the recovery container 6, even if a small amount of the molten salt 2 remains, it is fixed to the bottom and is difficult to recover, but the bottom plate 43 can be removed. This facilitates the recovery of the reduction product.

As described above, according to this embodiment, the operation of recovering the actinide oxide 3 and the metal actinide deposited on the outer container 6b becomes easy, and the work load can be reduced.

[Twenty-third Embodiment] FIG. 19 is a longitudinal sectional perspective view showing a twenty-third embodiment of the actinide oxide reduction device according to the present invention.

In FIG. 19, the present embodiment is the same as the second embodiment.
In addition to the configuration of the second embodiment, the baffle plate 4 is provided on the inner peripheral surface (inner wall) of the inner container 6a of the collection container 6 as in the twentieth embodiment.
5 are installed.

In the present embodiment configured as described above, the baffle plate 45 is provided on the inner peripheral surface of the inner container 6a of the collection container 6, whereby the stirring operation by the stirring device 7 becomes more effective.

As described above, according to the present embodiment, the baffle plate 4
5 allows for more effective stirring,
A high reduction rate can be obtained.

[Twenty-fourth Embodiment] FIG. 20 is a longitudinal sectional perspective view showing a main part of a twenty-fourth embodiment of the actinide oxide reduction device according to the present invention.

In FIG. 20, in this embodiment, a mesh 39 is provided on the bottom surface of the inner container 6a of the double cylindrical container.

In the present embodiment thus configured, when the recovery container is pulled up, the liquid substance such as the molten salt 2 passes through the mesh 39 and remains in the holding container 5, so that the solid reduction product (Actinide metal) alone can be selectively recovered. That is, only the metal actinide that has been reduced to a solid state can be recovered in the inner container 6a.

As described above, according to the present embodiment, metal actinides such as uranium, which are solid because their melting points are sufficiently higher than salts, can be separated from liquid salts and recovered. It becomes possible.

Further, in combination with the eighteenth embodiment, an actinide oxide such as plutonium, which may be present in a very fine shape, or a reduction product thereof has a melting point similar to that of a salt and becomes liquid. The recovery efficiency can be improved by recovering the metallic plutonium and the like which are considered to be present while separating them from the salt in the outer container 6b.

[Twenty-fifth Embodiment] FIG. 21 is a longitudinal sectional perspective view showing a main part of a twenty-fifth embodiment of the actinide oxide reduction device according to the present invention.

In FIG. 21, the present embodiment is the same as the second embodiment.
In addition to the configuration of the fourth embodiment, the bottom plate 43 of the inner container 6a of the collection container 6 is configured to be removable.

[0191] In the present embodiment thus configured, the bottom plate 43 of the inner container 6a of the collection container 6 can be removed.

As described above, according to this embodiment, since the bottom plate 43 of the inner container 6a of the recovery container 6 can be removed, the solid reduction product remains when the recovery container 6 is pulled up at the reduction reaction temperature. Even when the molten salt 2 is fixed to the inner container 6a of the recovery container 6 by the molten salt 2, it can be easily recovered by removing the bottom plate 43.

[Twenty-Sixth Embodiment] FIG. 22 is a longitudinal sectional perspective view showing a twenty-sixth embodiment of the actinide oxide reduction device according to the present invention.

In FIG. 22, the present embodiment is the same as the second embodiment.
In addition to the configuration of the fifth embodiment, a baffle plate 45 is provided on the inner peripheral surface (inner wall) of the inner container 6a.

In the present embodiment configured as described above, the stirring efficiency is improved by the baffle plate 45.

As described above, according to this embodiment, since the stirring efficiency is improved, the operation time can be shortened, and the reduction rate can be improved.

[0197]

As described above, according to the present invention, since the stirrer is provided, the reduction reaction of the actinide oxide can be efficiently performed, and a high reduction rate can be obtained.

Further, by providing a separating means in the collecting container, the reduced product can be easily separated and collected from the molten salt.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of an actinide oxide reduction device according to the present invention.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the actinide oxide reducing device according to the present invention.

FIG. 3 is a longitudinal sectional view showing third to seventh embodiments of the actinide oxide reduction device according to the present invention.

FIG. 4 is a longitudinal sectional view showing an actinide oxide reducing device according to an eighth embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a ninth embodiment of an actinide oxide reduction device according to the present invention.

FIG. 6 is a longitudinal sectional view showing a tenth embodiment of the actinide oxide reduction device according to the present invention.

FIG. 7 is a longitudinal sectional view showing an eleventh embodiment of the actinide oxide reduction device according to the present invention.

FIG. 8 is a longitudinal sectional perspective view showing a main part of a twelfth embodiment of an actinide oxide reducing device according to the present invention.

FIG. 9 is a longitudinal sectional perspective view showing a main part of a thirteenth embodiment of the actinide oxide reducing device according to the present invention.

FIGS. 10A and 10B are longitudinal sectional perspective views showing a main part of an actinide oxide reducing device according to a fourteenth embodiment of the present invention, and an enlarged view of a portion A in FIG. 10A.

FIG. 11 is a longitudinal sectional perspective view showing a main part of a fifteenth embodiment of the actinide oxide reducing device according to the present invention.

FIG. 12 is a longitudinal sectional view showing a sixteenth embodiment of an actinide oxide reducing device according to the present invention.

FIG. 13 is a longitudinal sectional perspective view showing a main part of a seventeenth embodiment of an actinide oxide reducing device according to the present invention.

FIG. 14 is a longitudinal sectional perspective view showing a main part of an eighteenth embodiment of the actinide oxide reducing device according to the present invention.

FIG. 15 is a longitudinal sectional perspective view showing a main part of a nineteenth embodiment of the actinide oxide reducing device according to the present invention.

FIG. 16 is a vertical sectional perspective view showing a main part of a twentieth embodiment of an actinide oxide reducing device according to the present invention.

FIG. 17 is a longitudinal sectional perspective view showing a main part of an actinide oxide reducing device according to a twenty-first embodiment of the present invention.

FIG. 18 is a longitudinal sectional perspective view showing a main part of an actinide oxide reducing device according to a twenty-second embodiment of the present invention.

FIG. 19 is a vertical sectional perspective view showing a main part of a 23rd embodiment of an actinide oxide reducing device according to the present invention.

FIG. 20 is a longitudinal sectional perspective view showing a main part of a twenty-fourth embodiment of the actinide oxide reducing device according to the present invention.

FIG. 21 is a longitudinal sectional perspective view showing a main part of a twenty-fifth embodiment of the actinide oxide reduction device according to the present invention.

FIG. 22 is a longitudinal sectional perspective view showing a main part of a twenty-sixth embodiment of the actinide oxide reducing device according to the present invention.

FIG. 23 is a longitudinal sectional view showing a conventional actinide oxide reduction device.

[Explanation of symbols]

 Reference Signs List 2 molten salt 3 actinide oxide 4 reducing agent 5 holding container 6 recovery container 7 stirring device 8 heating device 9 drive motor 15 shaft portion 16 stirring blade 22a, 22b support portion 25 heat shielding layer 26 penetration pipe 27 closure plug 28 division portion 30 Drive unit 31 Extension line 32 Thermocouple insertion pipe 33 Extension line 35 Connection unit 37 Joint unit 39 Mesh (separation means) 41 Bottom surface of holding container 43 Bottom plate 45 Baffle plate 47 Slit (separation means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masato Shindo 2-4, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Keihin Works, Toshiba Corporation (72) Reiko Fujita, Inventor 1 Reiko Fujita, Komukai Toshibacho, Saiwai-ku, Kawasaki-shi, Kanagawa Address Toshiba R & D Center (72) Inventor Akihiro Kawabe 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture In-house Toshiba Yokohama Office (72) Inventor Hidetane Irata Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa 66-2 Toshiba Engineering Co., Ltd. F-term (reference) 4K001 AA33 BA05 DA05 GB05 HA06 HA07 KA08

Claims (29)

[Claims] 1. A holding container containing a molten salt, an inside of the holding container, immersed in the molten salt, the molten salt being able to flow, and an actinide oxide and an actinide oxide in the molten salt. And a stirring device for diffusing the actinide oxide and the reducing agent into the molten salt in the collecting container, wherein the collecting container is configured to reduce the molten salt and the reducing salt. An actinide oxide reduction device, comprising a separation means for separating a reduction product after the reaction is completed. 2. The actinide oxide reduction device according to claim 1, wherein a heat shield member for thermally shielding a heating space for holding the molten salt at a constant temperature equal to or higher than a melting point and a room temperature space near room temperature. An actinide oxide reduction device, comprising: 3. The actinide oxide reduction device according to claim 1, wherein a through-passage that penetrates the heat shielding member and faces the inside of the recovery container is provided, and the through-passage is directly charged with a reducing agent. An actinide oxide reduction device, wherein the device is used as an agent injection hole. 4. The actinide oxide reducing device according to claim 3, wherein the through-passage is used as a sampling hole for sampling a salt phase in a molten state as needed, instead of the reducing agent introduction hole. Characteristic reduction device for actinide oxide. 5. The actinide oxide reduction device according to claim 3, wherein the through passage is used as an actinide oxide charging hole for loading the actinide oxide into the heating space instead of the reducing agent charging hole. An actinide oxide reduction device, characterized in that: 6. The apparatus for reducing actinide oxide according to claim 3, wherein an inert gas supply is provided in which a pipe for supplying an inert gas into a heating space is inserted through the through-path instead of the reducing agent introduction hole. An actinide oxide reduction device, which is used as a pipe insertion hole and an inert gas discharge pipe insertion hole for releasing pressure increased by the supplied inert gas. 7. The actinide oxide reduction device according to claim 3, wherein a thermocouple is inserted into the through-passage in one of the collection container and the holding container instead of the reducing agent introduction hole. An actinide oxide reduction device, which is used as a thermocouple insertion hole. 8. The actinide oxide reducing device according to claim 3, further comprising a closing plug for closing said through-passage. 9. The actinide oxide reduction device according to claim 1, wherein the stirring device includes a rotatable stirring blade. 10. The apparatus for reducing actinide oxide according to claim 9, wherein the stirring blade is attached to a shaft portion, and the shaft portion can be separated above a portion immersed in a molten salt in a use state. An actinide oxide reduction device, comprising: 11. The apparatus for reducing actinide oxide according to claim 9, wherein the stirring device includes a driving unit,
An actinide oxide reduction device, which is configured to be separable into a shaft portion and a stirring blade. 12. The actinide oxide reducing device according to claim 10, wherein the shaft portion is supported at two upper and lower positions. 13. The apparatus for reducing actinide oxide according to claim 1, wherein an extension of the through-path is provided in a gap between a stirring blade of the stirring device and an inner wall of the collection container. An actinide oxide reduction device, comprising: 14. The actinide oxide reduction device according to claim 1, further comprising a thermocouple insertion pipe for inserting a thermocouple between the holding container and the recovery container. Reduction device. 15. The actinide oxide reducing device according to claim 1, wherein the holding container has a height for holding a salt before melting. 16. The actinide oxide reducing device according to claim 1, wherein the holding container is formed to be thin. 17. The apparatus for reducing actinide oxide according to claim 15, wherein the holding container has a volume smaller than a bulk of the salt before melting and has a volume for holding a solidified salt after melting. An actinide oxide reducing device, comprising: an auxiliary container detachably connected to an upper portion of the main container and extended to a height for holding a salt before melting. 18. The actinide oxide reducing device according to claim 17, wherein the connecting portion of the holding container is provided intermittently in a circumferential direction. 19. The apparatus for reducing actinide oxide according to claim 1, wherein when the operation for reducing the actinide oxide is stopped, the recovery vessel is placed in the heating space while the recovery vessel is kept in the heating space. An actinide oxide reduction apparatus, wherein the apparatus is configured to be held above a liquid level so as to be separated from a salt phase. 20. The actinide oxide reduction device according to claim 1, wherein the separation means is a mesh, and the mesh is provided at the bottom of the recovery container. apparatus. 21. The actinide oxide reduction device according to claim 1, wherein the bottom surface of the recovery container is configured to be in contact with the bottom surface of the holding container. . 22. The actinide oxide reduction device according to claim 20, wherein the bottom plate of the recovery container is configured to be removable. 23. The actinide oxide reduction device according to claim 20, wherein a baffle plate is provided on an inner wall surface of the recovery container. 24. The apparatus for reducing actinide oxide according to claim 1, wherein the recovery container is formed of an inner and outer double cylindrical container, the inner container is removable, and the outer container has a predetermined height from the bottom. An actinide oxide reducing device, wherein a slit is formed from the set position, and a lower end of the inner container is separated from a bottom of the outer container. 25. The actinide oxide reducing device according to claim 24, wherein the bottom plate of the outer container is configured to be removable. 26. The actinide oxide reduction device according to claim 24, wherein a baffle plate is provided on an inner wall of the inner container. 27. The actinide oxide reduction device according to claim 24, wherein a mesh is provided on a bottom surface of the inner container. 28. The actinide oxide reduction device according to claim 27, wherein the bottom plate of the inner container is configured to be removable. 29. The actinide oxide reduction device according to claim 27, wherein a baffle plate is provided on an inner wall of the inner container.