JP2007084376A - Apparatus for manufacturing ammonium diuranate particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing ammonium diuranate particles, with which fuel kernel particles having high sphericity can be efficiently obtained under safe criticality control. <P>SOLUTION: In the apparatus for manufacturing the ammonium diuranate particles by dropping a raw liquid for manufacturing the ammonium diuranate particles containing uranyl nitrate and a thickener to an aqueous ammonia solution storage tank which stores an aqueous ammonia solution, the aqueous ammonia solution storage tank is formed in a flat board shape in the vertical direction and neutron absorbers are arranged inside the aqueous ammonia solution storage tank which is formed in the flat board shape. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus for producing ammonium heavy uranate particles, and more specifically, an apparatus for producing ammonium heavy uranate particles capable of efficiently obtaining fuel core particles having high sphericity under safe critical control. About.

  The core into which the fuel of the high-temperature gas reactor is charged is formed of graphite having a large heat capacity and excellent high-temperature soundness. In this high-temperature gas furnace, a gas such as helium gas that does not cause a chemical reaction even at high temperatures and has high safety is used as the cooling gas, so even if the outlet temperature is high, the cooling gas can be safely used. It can be taken out. Therefore, even if the temperature of the core rises to about 900 ° C., the cooling gas heated to a high temperature can be used safely in a wide range of fields such as power generation, hydrogen production equipment, and other chemical plants. Yes.

  Moreover, the fuel for a high temperature gas reactor to be charged into the high temperature gas reactor generally includes a fuel core and a coating layer that covers the periphery of the fuel core. The fuel core is, for example, fine particles having a diameter of about 350 to 650 μm formed by sintering uranium dioxide into a ceramic form.

The coating layer has a four-layer structure, and has a first layer, a second layer, a third layer, and a fourth layer from the fuel core surface side. The first layer is formed of low-density pyrolytic carbon having a density of about 1 g / cm ³ , functions as a gas reservoir for gaseous fission products (FP), and serves as a buffer for absorbing fuel nuclear swelling. It also has the function of The second layer is formed of high-density pyrolytic carbon having a density of about 1.8 g / cm ³ and has a function of holding a gaseous FP. The third layer is formed of silicon carbide (SiC) having a density of about 3.2 g / cm ³ , has a function of holding a solid FP, and is a main strength member of the coating layer. The fourth layer is formed of high-density pyrolytic carbon having a density of about 1.8 g / cm ³ and has a function of holding a gaseous FP and also a function of a protective layer of the third layer. . The diameter of the coated particles forming these coating layers is usually about 500 to 1500 μm.

  The coated fuel particles formed by forming the four coating layers on the surface of the fuel core are dispersed in a graphite matrix and formed into a fixed shape of a fuel compact. The fuel compact is formed of graphite. A certain amount is accommodated in the cylinder and plugged up and down to form a fuel rod. Ultimately, this fuel rod is inserted into a plurality of insertion holes of the hexagonal column type graphite block, and a core is formed by arranging a plurality of the hexagonal column type graphite blocks in a honeycomb shape and stacking a plurality of stages. The

  Such a HTGR fuel can generally be manufactured through the following steps. First, a uranium nitrate solution is prepared by dissolving uranium oxide powder in nitric acid. Next, the uranyl nitrate solution and the thickener-containing aqueous solution are mixed to prepare a stock solution for producing ammonium biuranate particles (hereinafter sometimes simply referred to as “stock solution”). A thickener is a substance added to adjust the viscosity of a droplet of uranyl nitrate, which is a stock solution dropped into an aqueous ammonia solution described later.

  Examples of the thickener include polyvinyl alcohol, a resin that has a property of solidifying under alkaline conditions, polyethylene glycol, and metroses. The stock solution prepared in this manner is cooled to a predetermined temperature, and then dropped from the small-diameter original droplet lower nozzle of the original droplet lowering device into the aqueous ammonia solution in the ammonia aqueous solution storage tank by vibrating the nozzle. The

  The droplets dropped into the aqueous ammonia solution are sprayed with ammonia gas in the space up to the surface of the aqueous ammonia solution. Since the surface of the droplet gels by this ammonia gas and a film is formed, the droplet particles on which the gel film is formed are prevented from being deformed by impact when falling onto the surface of the aqueous ammonia solution, and the ammonia in the aqueous ammonia solution storage tank To form ammonium deuterated uranate particles. The formed ammonium heavy uranate particles are deposited in the lower part of the aqueous ammonia storage tank, and the lower ammonium heavy uranate particles are not deformed by the load of the ammonium heavy uranate particles riding on the upper part of the aqueous ammonia storage tank. The aqueous ammonia solution is circulated from the lower side to the upper side of the aqueous ammonia solution storage tank.

  The ammonium heavy uranate particles formed in the ammonia aqueous solution storage tank are transferred to a post-treatment device that is connected to the ammonia aqueous solution storage tank. The transfer of the heavy ammonium uranate particles to the post-treatment device is normally performed by opening a valve of a pipe connecting the ammonia aqueous solution storage tank and the post-treatment device and dropping it together with the aqueous ammonia solution by its own weight. In this post-treatment device, while rotating the post-treatment tank, by heating, the uranyl nitrate and ammonia are completely reacted to the center of the particles to produce ammonium heavy uranate (ripening treatment), heavy uranic acid with hot water, etc. It is an apparatus that performs a process for cleaning ammonium particles (cleaning process) and a process for drying (drying process).

  Aged, washed and dried ammonium heavy uranate particles are roasted in air to form uranium trioxide particles. Further, the uranium trioxide particles are reduced and sintered to become high-density ceramic-like uranium dioxide particles. The uranium dioxide particles thus formed are classified and obtained as fuel core fine particles having a predetermined particle diameter.

  The fuel core particles obtained in this way are loaded onto a fluidized bed and coated by thermally decomposing the coating gas. For example, the first layer can be formed by pyrolyzing acetylene at about 1400 ° C., and the second and fourth layers can be formed by pyrolyzing propylene at about 1500 ° C. it can. For example, the third layer can be formed by thermally decomposing methyltrichlorosilane at about 1600 ° C. A normal fuel compact can be manufactured by press-molding or molding coated fuel particles into a hollow cylindrical shape or a medium-density cylindrical shape together with a graphite matrix material composed of graphite powder, a binder, and the like, followed by firing. (See Non-Patent Documents 1 and 2).

"Reactor Material Handbook" p221-p247, published October 31, 1977, published by Nikkan Kogyo Shimbun "Nuclear Power Handbook" p161-p169, issued on December 20, 1995, Ohm Corporation

  In the production of such nuclear fuels, as a means of preventing criticality accidents, in general, a “mass limit” in which the amount of uranium handled is less than the critical mass and that a critical state occurs regardless of the amount of uranium. There is a “shape restriction” that uses a device with no shape or size.

  When the “mass restriction” is used as a means for preventing a criticality accident, the maximum handling amount for uranium having a concentration of 10% or less is 9.6 kg, and the maximum handling amount for uranium having a concentration of 20% or less is 4 kg. Therefore, the batch size of each process must be less than or equal to the above value. From a safer point of view, considering the case of double loading by mistake, the batch size of each process must be ½ or less of the above value, the production efficiency is reduced, from the viewpoint of mass production Is a tool that cannot be considered an appropriate criticality control measure.

  On the other hand, when the “shape restriction” is used as a means for preventing criticality accidents, the diameter of cylindrical equipment for uranium with a concentration of 10% or less is 19.8 cm or less, and the thickness of flat equipment is 8.3 cm or less. Moreover, the diameter of the cylindrical equipment with respect to uranium with a concentration of 20% or less is 17.4 cm or less, and the thickness of the flat equipment is 6.7 cm or less.

  When the “shape restriction” is used as a means for preventing criticality accidents, there is no restriction on the amount of uranium to be handled, so it can be said that it is a preferable means for mass production. Therefore, the facility for producing fuel nuclei had to be in the shape of an elongated cylinder or a thin flat plate.

  By the way, among the manufacturing processes of the HTGR fuel, uranium oxide powder is dissolved in nitric acid to prepare a uranyl nitrate solution, and this prepared uranyl nitrate solution is mixed with a thickener aqueous solution. In the step of dropping the prepared ammonium heavy uranate particle production stock solution into the aqueous ammonia solution to form ammonium heavy uranate particles, the aqueous solution containing the aqueous ammonia solution was previously formed in the aqueous ammonia storage tank. Since the ammonium heavy uranate particles formed later are deposited on the ammonium heavy uranate particles, the previously formed ammonium heavy uranate particles are deformed by the weight, and the resulting fuel core particles There was a problem that the sphericity deteriorated.

  The present applicant solved the problem by circulating an aqueous ammonia solution from the bottom to the top of the aqueous ammonia storage tank, and applied for a patent based on this finding (Japanese Patent Application Nos. 2003-348727 and 2004-026134). However, when highly enriched uranium is used as a raw material, the aqueous ammonia storage tank must be an elongated cylindrical or thin flat tank, so that the ammonium heavy uranate particles are sufficiently fluidized only by circulating the aqueous ammonia solution. The problem of worsening the sphericity of the resulting fuel core particles has emerged again.

  An object of the present invention is to provide an apparatus for producing ammonium deuterated uranate particles, which can solve such conventional problems and can efficiently obtain fuel core particles having high sphericity under safe criticality control. Is the subject.

  In order to solve the above problems, the present inventor has made various studies on the shape of the aqueous ammonia storage tank and the internal structure of the aqueous ammonia storage tank. As a result, the aqueous ammonia storage tank was formed into a flat plate shape in the vertical direction. It has been found that the above problem can be solved by disposing a neutron absorber inside the aqueous ammonia storage tank, and the present invention has been completed based on this finding.

That is, the means for solving the problems of the present invention are:
An apparatus for producing ammonium heavy uranate particles produced by dropping a stock solution for producing ammonium heavy uranate particles containing uranyl nitrate and a thickener into an ammonia aqueous solution storage tank for storing an ammonia aqueous solution, the ammonia aqueous solution storage tank Is formed in a flat plate shape in the vertical direction, and a neutron absorber is disposed inside the ammonia aqueous solution storage tank formed in the flat plate shape. is there.

Preferred embodiments of the above means of the present invention include the following (1) to (4) ammonium biuranate particle production apparatuses.
(1) The apparatus for producing ammonium heavy uranate particles, wherein the neutron absorber is a rod-shaped body.
(2) The apparatus for producing ammonium heavy uranate particles, wherein the number of arranged neutron absorbers is 2 to 15.
(3) An apparatus for producing ammonium heavy uranate particles, wherein the neutron absorber is formed of stainless steel containing boron.
(4) An apparatus for producing ammonium heavy uranate particles, comprising an ammonia aqueous solution circulation pipe for circulating an aqueous ammonia solution from the lower side to the upper side of the aqueous ammonia solution tank in the aqueous ammonia solution tank.

  The apparatus for producing ammonium heavy uranate particles according to the present invention is an aqueous ammonia storage tank for producing ammonium heavy uranate particles by dropping a stock solution, and is formed in a flat plate shape in the vertical direction. Therefore, it is possible to increase the flat plate thickness of the ammonia aqueous solution storage tank when the shape is limited without being restricted by the shape. Moreover, since a neutron absorber is disposed inside the aqueous ammonia storage tank formed in the flat plate shape, even when using highly enriched uranium as a raw material, the size of the apparatus for producing ammonium deuterated uranium particles There is an effect that ammonium heavy uranate particles can be produced under safe critical control without reducing (batch size).

  Furthermore, by arranging a plurality of the neutron absorbers, it becomes possible to increase the thickness of the flat plate in the ammonia aqueous solution storage tank formed in a flat plate shape when the shape is limited, and the batch size can be further increased. Since it can be enlarged, the aqueous ammonia solution can be made to flow smoothly by circulation of the aqueous ammonia solution. Due to the flow of the aqueous ammonia solution, the formed ammonium heavy uranate particles also flow, and in the aqueous ammonia storage tank, the later formed ammonium heavy uranate particles are deposited on the previously formed ammonium heavy uranate particles. There is nothing. Therefore, there is an effect that fuel nuclear particles having high sphericity can be finally obtained without causing deformation of ammonium heavy uranate particles.

  An example of an apparatus for producing ammonium heavy uranate particles according to the present invention will be described with reference to the drawings. Fig.1 (a) is a perspective view which shows an example of the manufacturing apparatus of the ammonium heavy uranate particle | grains of this invention which has a notch part partially.

  An apparatus for producing ammonium heavy uranate particles 1 according to the present invention has an ammonia aqueous solution storage tank 3 for storing an aqueous ammonia solution 2 as a main body, and an upper lid 4 of the ammonia aqueous solution storage tank 3 has an uranyl nitrate, a thickener, A raw liquid droplet lower hole 5 is provided for dropping a raw solution for producing ammonium biuranium particles containing. The stock solution cooled to a predetermined temperature from the stock droplet lower hole 5 becomes a stock solution droplet 6 by vibrating a small-sized stock droplet lower nozzle (not shown) into the ammonia aqueous solution storage tank 3. It is dripped. The droplet 6 of the stock solution dropped into the aqueous ammonia storage tank 3 reacts with the ammonia in the aqueous ammonia storage tank 3 and the uranyl nitrate to form ammonium heavy uranate particles. 7 is an ammonia aqueous solution circulation pipe.

  In the production apparatus 1 for ammonium heavy uranate particles of the present invention, the ammonia aqueous solution storage tank 3 is formed in a flat plate shape in the vertical direction. As this flat plate-shaped ammonia aqueous solution storage tank 3, for example, as shown in FIG. 1 (a), a vertically long home base type tank can be mentioned, but it is formed in a flat plate shape in the vertical direction. As long as there is no limit to its external shape. For example, as shown in FIG. 1B, when the longitudinal direction is the major axis and the lateral direction is the minor axis, the minor axes may have different lengths. As shown, it may be oval. It is preferable that the bottom part of the aqueous ammonia solution storage tank 3 shown in FIGS. 1A and 1B is formed in a tapered shape. An ammonia aqueous solution circulation pipe 7 is provided at the tip of the bottom of the ammonia aqueous solution storage tank 3.

  FIG. 2 is a view including the AA cross section of FIG. In the production apparatus 1 for ammonium heavy uranate particles according to the present invention, a neutron absorber 8 is disposed inside the ammonia aqueous solution storage tank 3 formed in the flat plate shape. The neutron absorber 8 is a member having a function of absorbing neutrons emitted from the aqueous ammonia storage tank 3 and neutrons entering from the outside and preventing the neutrons from causing fission with uranium.

  The neutron absorber 8 is not limited as long as it is formed of a material that can absorb neutrons. Examples of materials that can absorb neutrons include elements such as B, Gd, Sm, Eu, Cd, Dy, In, Er, Ta, Rh, Tm, Lu, Hf, Au, Re, and Ag. Examples of the metal include Among these, stainless steel containing boron (B) is preferable. The amount of boron contained in the stainless steel is not limited, but is usually at least 0.5% by mass, preferably 1.0 to 2.0% by mass.

  The shape of the neutron absorber 8 is not limited as long as the neutron absorber 8 has a shape that can be disposed inside the ammonia aqueous solution storage tank 3 formed in a flat plate shape. For example, a rod-like body such as a round bar or a square bar, A plate-like body such as a smooth plate or a plate having an uneven surface can be mentioned. Among these, a rod-like body is preferable, and a round bar is particularly preferable as shown in FIG. This is because the neutron absorption area can be increased and deformation is less likely to occur even when the flowing particles collide.

  Moreover, it is preferable that the said neutron absorber 8 is multiply arranged, and as long as it is plural, there is no restriction | limiting in the number of arrangement | positioning, but it is preferable that it is 2-15. By arranging a plurality of neutron absorbers 8, the neutron absorption capacity is increased, and the flat plate thickness in the aqueous ammonia storage tank 3 formed in the flat plate shape when the shape is limited can be increased. This is because the batch size can be further increased.

  Fig.3 (a) is a figure which shows the BB cross section of FIG. As shown in FIG. 3A, the neutron absorber 8 is preferably disposed horizontally in the aqueous ammonia storage tank 3 formed in a flat plate shape. This is because the batch size can be increased by arranging them horizontally. But the arrangement | positioning state of the said neutron absorber 8 does not necessarily need to be horizontal, and the both ends of the said neutron absorber 8 do not need to be in contact with the inner wall of the said ammonia aqueous solution storage tank 3. FIG. For example, the arrangement states as shown in FIGS.

  Further, as shown in FIG. 2 and FIG. 3A, the interval between the neutron absorbers 8 is preferably substantially equal. However, the neutron absorber 8 is not necessarily limited to substantially equal intervals, and the desired neutrons are not necessarily limited. What is necessary is just to arrange | position suitably according to the number of the absorbers 8. FIG.

  In the apparatus 1 for producing ammonium heavy uranate particles according to the present invention, as shown in FIG. 1 (a) and FIG. 2, an ammonia aqueous solution circulation pipe 7 for circulating the aqueous ammonia solution 2 from the lower side to the upper side of the aqueous ammonia solution tank 3 is provided. It is preferable to provide. Due to the flow of the aqueous ammonia solution 2, the formed ammonium heavy uranate particles flow, and in the ammonia aqueous solution storage tank 3, the ammonium heavy uranate particles formed later on the previously formed ammonium heavy uranate particles. This is because there is no deposition, so that the ammonium heavy uranate particles are not deformed, and finally, fuel core particles having a high sphericity can be obtained. Reference numeral 9 denotes a liquid feed pump for circulating the aqueous ammonia solution 2.

In order to produce ammonium heavy uranate particles using the production apparatus 1 for ammonium heavy uranate particles of the present invention, first, for example, uranium oxide is dissolved in nitric acid to prepare a uranyl nitrate solution. Although there is no particular limitation on the preparation conditions at this time, the molar ratio of nitric acid (HNO ₃ ) / uranium (U) is usually 2.1 to 2.6, preferably 2.3 to 2.5, Usually, it is prepared by mixing at 90 to 140 ° C, preferably 95 to 130 ° C.

  Next, the uranyl nitrate solution prepared as described above and the thickener aqueous solution are mixed to prepare a stock solution for producing ammonium biuranate particles. Examples of the thickener include water-soluble polymer substances such as polyvinyl alcohol, carboxyvinyl polymer, polyvinylpyrrolidone, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyethylene glycol, metroses, and water-soluble cyclic ether, and coagulation under alkaline conditions. Examples thereof include resins having the property of Among these, polyvinyl alcohol is preferable. Two or more of these thickeners may be used in combination.

  The stock solution may contain an additive such as tetrahydrofurfuryl alcohol as a substance to be added to reduce and adjust the viscosity of the prepared stock solution.

  In the present invention, the stock solution for production of ammonium biuranate particles containing uranyl nitrate and a thickener prepared as described above is cooled to a predetermined temperature, and then a nozzle with a small-diameter original droplet (not shown) is shown. From this, the nozzle is vibrated and dropped into the ammonia aqueous solution storage tank 3. In the space until reaching the surface of the aqueous ammonia solution 2, ammonia gas is sprayed onto the droplet 6 of the undiluted solution to form a droplet in which the surface of the droplet has gelled and a film is formed. The uranyl nitrate in the undiluted solution dropped into the ammonia aqueous solution storage tank 3 reacts with ammonia to form ammonium heavy uranate particles.

  The formed ammonium deuterated uranium particles flow in the ammonia aqueous solution storage tank 3 while flowing together with the aqueous ammonia solution 2 circulating from below to the upper side of the aqueous ammonia solution storage tank 3 through the ammonia aqueous solution circulation pipe 7 by driving the liquid feed pump 9. Circulate inside and outside. By circulating in this way, the reaction between ammonia and uranyl nitrate is promoted, and a firm ammonium heavy uranate is produced.

  The ammonium uranate particles thus produced are then subjected to aging treatment, washing treatment and drying treatment, and further, roasted, reduced and sintered, whereby high-density ceramic uranium dioxide particles are obtained. It becomes. The uranium dioxide particles are classified and obtained as fuel core fine particles having a predetermined particle diameter.

  According to the present invention, there is provided an apparatus for producing ammonium heavy uranate particles capable of efficiently obtaining fuel core particles having high sphericity under safe critical control, and is used in the field of manufacturing high temperature gas reactor fuel. There is a tremendous contribution.

The sphericity of the fuel core particle can be obtained from the following equation by measuring the diameter of the fuel core particle from an arbitrary direction for a certain particle.
Sphericality = (maximum diameter during measurement) / (minimum diameter during measurement)
The sphericity of the fuel core particle is an index representing how close the particle is to the true sphere, and the closer to the true sphere, the closer to 1.00.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples.

(Example)
Ammonium heavy uranate particles were produced using the production apparatus 1 for ammonium heavy uranate particles shown in FIGS. 1 (a), 2 and 3 (a).

[Preparation example of uranyl nitrate solution]
Uranium oxide powder was dissolved in nitric acid and mixed at 100 ° C. for 1.5 hours to prepare a uranyl nitrate solution (0.76 mol-U / L).

[Preparation Example of Stock Solution for Production of Ammonium Heavy Uranate Particles]
A uranyl nitrate solution prepared as described above and a polyvinyl alcohol aqueous solution containing tetrahydrofurfuryl alcohol were mixed to prepare a stock solution for producing ammonium biuranate particles. The concentration of polyvinyl alcohol in this stock solution was 12.5 g / L, and the ratio of tetrahydrofurfuryl alcohol to the whole stock solution was 45% by volume. Moreover, the viscosity of this undiluted | stock solution was 53 * 10 < ^-3 > Pa * s (53cP) at 20 degreeC.

[Production of ammonium heavy uranate particles]
After the stock solution for producing ammonium biuranate particles containing uranyl nitrate and a thickener prepared as described above was cooled to 10 ° C., it was supplied from a nozzle having a small diameter of the original droplet (not shown). By oscillating the nozzle, it was dropped into the ammonia aqueous solution storage tank 3 as a liquid droplet 6. Ammonia gas was sprayed onto the droplet 6 of the stock solution in a space until reaching the surface of the aqueous ammonia solution 2. The uranyl nitrate in the stock solution dropped into the ammonia aqueous solution storage tank 3 reacted with ammonia to form ammonium heavy uranate particles.

  The formed ammonium heavy uranate particles are driven from the lower part of the ammonia aqueous solution storage tank 3 to the upper part through the ammonia aqueous solution circulation pipe 7 by driving the liquid feed pump 9 to a speed about twice the sedimentation speed of the ammonium heavy uranate particles. The aqueous ammonium uranate was circulated while flowing together with the aqueous ammonia solution 2 in such a liquid feed amount as described above.

(Reference example)
[Manufacture of fuel core particles]
Thereafter, the ammonium biuranate particles produced as described above were placed in a post-treatment tank (not shown) together with an aqueous ammonia solution, and aged at 80 ° C. for 1 hour while rotating the post-treatment tank. Thereafter, it was washed with water at 80 ° C. and further dried at 100 ° C. for 3 hours to obtain dry ammonium uranate particles.

  Further, the dried ammonium heavy uranate particles were roasted in the atmosphere at 550 ° C. for 3 hours to obtain uranium trioxide particles. The uranium trioxide particles were subjected to reduction treatment at 600 ° C. for 3 hours in a hydrogen gas atmosphere, followed by sintering treatment at 1550 ° C. for 1 hour to produce ceramic fuel core fine particles. The average sphericity of the fuel core fine particles was 1.04.

(Comparative example)
Ammonium heavy uranate particles were produced in the same manner as in the examples except that the apparatus for producing ammonium heavy uranate particles in which the neutron absorber 8 was not disposed was used. Manufactured. The average sphericity of the fuel core particles exceeded 1.2.

FIG. 1 is a perspective view showing an example of an apparatus for producing ammonium heavy uranate particles according to the present invention. FIG. 2 is a view including the AA cross section of FIG. FIG. 3 is a diagram showing a BB cross section of FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus of ammonium heavy uranate particle 2 Ammonia aqueous solution 3 Ammonia aqueous solution storage tank 4 Upper cover 5 Original liquid droplet lower hole 6 Liquid droplet of original liquid 7 Ammonia aqueous solution circulation piping 8 Neutron absorber 9 Liquid feed pump

Claims (5)

  An apparatus for producing ammonium heavy uranate particles produced by dropping a stock solution for producing ammonium heavy uranate particles containing uranyl nitrate and a thickener into an ammonia aqueous solution storage tank for storing an ammonia aqueous solution, the ammonia aqueous solution storage tank Is formed in a flat plate shape in the vertical direction, and a neutron absorber is disposed in the ammonia aqueous solution storage tank formed in the flat plate shape.   The apparatus for producing ammonium heavy uranate particles according to claim 1, wherein the neutron absorber is a rod-shaped body.   The apparatus for producing ammonium heavy uranate particles according to claim 1 or 2, wherein the number of arranged neutron absorbers is 2 to 15.   The apparatus for producing ammonium heavy uranate particles according to any one of claims 1 to 3, wherein the neutron absorber is formed of stainless steel containing boron. The apparatus for producing ammonium heavy uranate particles according to any one of claims 1 to 4, wherein the ammonia aqueous solution storage tank is provided with an ammonia aqueous solution circulation pipe for circulating the ammonia aqueous solution from below to above the ammonia aqueous solution storage tank.

Images