JP2012047546A - Fluorination device, fluorination method and reprocessing method for nuclear fuel material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress adhesion of FP fluoride to an inner wall surface of a flame furnace when a nuclear fuel material is reacted with fluorine gas using a flame furnace type fluorination device.SOLUTION: A nuclear fuel material 1 and fluorine gas 4 are supplied into a flame furnace 8 and made to react with each other to form a flame 9; a flocculant 6 which flocculates semi-volatile FP fluoride is supplied downward in the flame furnace 8 and outside the flame 9 to flocculate the semi-volatile FP fluoride diffused from the flame 9 side to the inner wall surface side of the flame furnace 8 on a surface of the flocculant 6 by a temperature difference; and the flocculant 6 with the semi-volatile FP fluoride flocculated thereon is collected as a mixed residue 12 together with other FP fluorides collected by a residue collection part 11.

Description

  The present invention belongs to the technical field relating to the reprocessing of spent nuclear fuel and the fluorination of nuclear fuel material in a uranium conversion facility and a spent nuclear fuel reprocessing facility.

In the nuclear industry, uranium (U), a nuclear fuel material, is reacted with fluorine gas (F ₂ ) to form uranium hexafluoride (UF ₆ ) for the purpose of uranium conversion or spent fuel reprocessing. There is technology.

  As devices for reacting uranium with fluorine gas, there are a device using a fluidized bed and a fluorination device using a flame furnace as shown in Non-Patent Document 1 and Non-Patent Document 2.

The shape of the fluorination apparatus using a fluidized bed is, for example, a square reaction vessel. Fluorine gas is blown into a reaction vessel loaded with uranium and reacted at a relatively low temperature (300 to 535 ° C.) to obtain UF ₆ .

The shape of a fluorination apparatus using a flame furnace is generally an upright cylindrical shape. Uranium and fluorine gas are supplied from the center of the top of the cylinder, and uranium and fluorine gas are heated at a high temperature (reaction section is 1200 to 1600 ° C. obtaining UF ₆ is reacted with). Since the reaction part of uranium and fluorine gas looks like a flame, this reaction part is called a flame.

In uranium conversion, uranium to be reacted with fluorine gas is uranium oxide (UO ₂ ) obtained by purifying natural uranium or oxide of reprocessed and recovered uranium, which is commonly characterized by high purity uranium. For example, in uranium conversion, uranium oxide and hydrogen fluoride (HF) are reacted as shown in Chemical Formula 1 to obtain uranium tetrafluoride (UF ₄ ), and UF ₄ and fluorine gas are reacted as shown in Chemical Formula 2. To get UF ₆ . The reaction of Formula 2 is performed in a fluidized bed or a flame furnace.

UO ₂ + 4HF → UF ₄ + 2H ₂ O (1)
UF ₄ + F ₂ → UF ₆ (Chemical formula 2)
As a spent fuel reprocessing technique, there is a fluoride volatilization method disclosed in Patent Document 1. The purpose of the fluoride volatilization method is to react spent fuel with fluorine gas to separate and recover uranium contained in the spent fuel as volatile UF ₆ and to reuse uranium as a nuclear fuel. In addition to uranium, spent fuel includes fission products (hereinafter referred to as FP). When the uranium oxide in the spent fuel reacts with the fluorine gas as shown in Chemical Formula 3, FP also reacts with the fluorine gas to generate, for example, FP fluoride as shown in Table 1.

UO ₂ + 3F ₂ → UF ₆ + O ₂ (Chemical formula 3)
Research on the fluoride volatilization method for the purpose of reprocessing began in the 1950s. As shown in Non-Patent Document 2, the fluorination reactor was a fluidized bed system at the beginning of the research, but recently, Research has begun.

JP 2002-257980 A

M. Benedict et al. Written and translated by Kiyose Kihei, “Chemical Engineering of Nuclear Fuels and Materials”, Nikkan Kogyo Shimbun, March 30, 1984, P152-156 Published by the Japan Atomic Energy Society, “Fuel Cycle Technology-Toward the Construction of the 21st Century Fuel Cycle-”. May 31, 2002, P96-98

In the reprocessing of spent fuel by the fluoride volatilization method, the fluorination reaction temperature in the fluidized bed is about 300 ° C. throughout the reactor, and volatilized UF ₆ contains, for example, molybdenum (Mo) having a boiling point of 300 ° C. or less. Fluoride gases such as ruthenium (Ru), niobium (Nb), and antimony (Sb) coexist, and the other FP fluorides shown in Table 1 do not volatilize and are separated from UF ₆ as a solid residue. Table 1 shows the boiling point (° C.) of the FP fluoride.

  On the other hand, when the spent fuel and the fluorine gas are reacted in the flame furnace, the flame is 1200 ° C. to 1600 ° C., but the temperature decreases on the outer periphery of the flame, and the temperature of the flame furnace inner wall surface is about 300 ° C. Therefore, we pay attention to the volatilization behavior of FP fluoride. As a problem specific to the flame furnace, some FP fluoride volatilizes once in the frame part, but then condenses on the surface of the inner wall of the flame furnace. Newly found to be volatile).

According to Table 1, Mo, Ru, Nb, and Sb fluorides volatilize with UF ₆ as in the fluidized bed method, and yttrium (Y), barium (Ba), samarium (Sm), and strontium (Sr) fluorides. The compound remains as a solid residue without volatilization. Fluorine such as tin (Sn), zirconium (Zr), cesium (Cs), and rubidium (Rb) has a boiling point of 1200 ° C. to 1600 ° C. or less of the flame temperature. It is expected to condense near the inner wall surface and stick to the inner wall surface of the flame furnace.

  In the fluidized bed system, there is no temperature gradient in the reaction part as in the flame furnace system, and the fluorination temperature is relatively low, so that the semivolatile FP fluoride does not adhere to the inner surface of the reaction bed. In addition, since fluorination in uranium conversion handles high-purity uranium, semi-volatile FP fluoride does not stick regardless of the fluorination apparatus. In other words, only in the fluoride volatilization method in which spent fuel is reacted with fluorine in a flame furnace method, it can be said that the semi-volatile FP fluoride is fixed to the inner surface of the flame furnace.

When semi-volatile FP fluoride adheres to the surface of the inner wall of the flame furnace, the exposure risk increases during work such as flame furnace replacement due to an increase in the dose on the flame furnace surface. In addition, when a large amount of FP fluoride adheres and the flame furnace volume changes, the gas flow rate changes and the operating conditions change, and the attached FP fluoride and UF ₆ or plutonium hexafluoride ( Nuclear fuel materials such as PuF ₆ ) may form double salts and accumulate in the flame furnace.

  Accordingly, an object of the present invention is to provide a nuclear fuel material reprocessing method, a fluorination method, and a fluorination apparatus that can prevent the semivolatile FP fluoride from adhering to the surface of the inner wall of the flame furnace.

  According to another aspect of the present invention, there is provided a fluorination apparatus for a nuclear fuel material that uses a flame furnace for reacting a nuclear fuel material and a fluorine gas. A nuclear fuel material comprising: a mechanism for supplying a semi-volatile FP fluoride to the lower portion of the fluorination apparatus into the flame furnace at a position on the outer peripheral side of the flame furnace from a supply port. It is a fluorination device.

  According to another aspect of the present invention, there is provided a method for fluorinating a nuclear fuel material, wherein the nuclear fuel material is reacted with fluorine gas in a fluorination apparatus using a flame furnace. The nuclear fuel material attached to the upper part and the fluorine gas supply port are supplied into the flame furnace for reaction, and semi-volatile FP fluoride is introduced from the outer peripheral side of the flame furnace with respect to the supply port. A nuclear fuel material characterized in that a substance to be entrained in a lower part of a fluorination apparatus is supplied into the flame furnace and the semi-volatile FP fluoride is caused to entrain with the substance and flow downward in the flame furnace. This is a fluorination method.

  The nuclear fuel material reprocessing method for achieving the object of the present invention is to supply nuclear fuel material and fluorine gas from the nuclear fuel material and fluorine gas supply ports attached to the upper part of the flame furnace and to react with the flame furnace. At the same time, an agglomerate that aggregates semi-volatile FP fluoride is supplied from a position on the outer peripheral side of the flame furnace from the supply port of the nuclear fuel material and the fluorine gas, and the fluorination of the nuclear fuel material and the fluorine gas is performed. The non-volatile fluoridation residue generated by the reaction and the agglomerated material supplied to the flame furnace are collected as a mixed residue, and the mixed residue is reacted with water vapor to be converted into an oxide, which is then dissolved and solvent extracted. The nuclear fuel material reprocessing method is characterized in that the nuclear fuel material in the mixed residue is separated and recovered.

  According to the present invention, there is a direct effect that it is possible to suppress the semivolatile FP fluoride volatilized temporarily in the frame in the frame furnace from diffusing from the frame to the frame furnace wall and adhering to the surface of the frame furnace inner wall. can get.

  This effect reduces the exposure risk during work such as flame furnace replacement by reducing the radiation dose on the wall surface of the flame furnace, prevents FP fluoride from adhering to the flame furnace inner wall surface and affecting the operating conditions of the flame furnace, It is possible to indirectly obtain the effect of reducing the adhesion of the nuclear fuel material to the surface of the inner wall of the flame furnace.

It is a schematic diagram of the longitudinal cross-section of the fluorination apparatus using the flame furnace by Example 1 of this invention. It is a schematic diagram of the longitudinal cross-section of the fluorination apparatus using the flame furnace by Example 2 of this invention. It is the flowchart figure which showed the process of the reprocessing method of the nuclear fuel material by Example 3 of this invention.

  In reprocessing by fluoride volatilization method in which fluorine and spent fuel are reacted in a flame furnace method, the inventor has invented two methods as a means to suppress the sticking of semi-volatile FP fluoride to the inner surface of the flame furnace It came to do.

  The first idea is as follows. That is, when the spent fuel and fluorine gas are reacted, a fine solid compound is continuously supplied from the top between the frame and the inner wall surface of the frame furnace. The supplied solid compound is desirably supplied near the surface of the inner wall of the flame furnace. In this case, the surface temperature of the solid compound is approximately the same as the surface of the inner wall of the flame furnace.

  The semi-volatile FP fluoride volatilized temporarily in the frame is cooled and condensed on the surface of the solid compound while diffusing from the frame to the frame furnace wall, and recovered as a solid residue together with the solid compound. The conditions of the solid compound include that it does not react with fluorine gas or reacts but forms a passive state on the surface and hardly undergoes fluorination, and is non-volatile in a flame furnace.

  Table 2 shows an example of the solid compound.

Since the fluorides of group 2 elements and lanthanoid fluorides in Table 2 are not further fluorinated, they can be said to be non-volatile solid compounds that do not react with fluorine gas. Sintered alumina but it generates the AlF ₃ reacts with fluorine gas, AlF ₃ generated at the surface does not proceed fluorination reaction until the inside becomes passive, and non-volatile.

  The contents of the second idea are as follows. That is, when the spent fuel and the fluorine gas are reacted, a carrier gas is continuously supplied from the top between the frame and the surface of the inner wall of the frame furnace.

While semi-volatile FP fluoride volatilized temporarily in the frame diffuses in the gas from the frame to the frame furnace wall, the semi-volatile FP fluoride is exhausted from the frame furnace with the carrier gas, and the residue recovery unit To recover as a solid residue. When a gas that reacts with fluorine gas is supplied as a carrier gas, the fluorine gas is consumed by the reaction. For example, nitrogen gas (N ₂ gas) or oxygen gas (O ₂ gas) that does not react with fluorine gas is used as the carrier gas. Fluorine gas (F ₂ gas) or argon gas (Ar gas) may be used.

  Embodiment 1 of the present invention will be described below with reference to FIG. The embodiment of the present invention is an example relating to a method and apparatus for fluorinating nuclear fuel material. As shown in FIG. 1, the fluorination apparatus includes a cylindrical flame furnace 8, a nuclear fuel material inlet 2, a fluorine gas inlet 3, an agglomerate inlet 5, and a funnel at the bottom of the flame furnace 8. The residue collection unit 11 is connected to the residue collection unit 11 and the vent 13 is provided in the residue collection unit 11 and exhausts the off-gas 7 from the residue collection unit 11.

  The outline of mass transfer is described below. The nuclear fuel material 1 will be described as a spent fuel, for example. The shape of the flame furnace 8 is an upright cylindrical shape. The nuclear fuel material inlet 2 is at the center of the top of the cylinder, the fluorine gas inlet 3 is at the outer periphery of the nuclear fuel material inlet 2, and the aggregate inlet 5 is at the outer periphery of the fluorine gas inlet 3. Is provided. A residue recovery unit 11 is provided at the lower part of the flame furnace 8, and a vent hole 13 through which the offgas 7 is exhausted is provided in the residue recovery unit 11.

  The nuclear fuel material 1 supplied from the nuclear fuel material inlet 2 reacts with the fluorine gas 4 supplied from the fluorine gas inlet 3 to form a frame 9 which is a reaction part of the fluorination reaction, and generates fluoride. Simultaneously with the supply of the nuclear fuel material 1, the supply of the aggregate 6 from the aggregate inlet 5 is started. The agglomerate 6 is a group 2 element fluoride or lanthanoid fluoride shown in Table 2 and fine particles of sintered alumina, and supplies about 0.1% of the supply amount of the nuclear fuel material 1.

When sintered alumina is used as the aggregate 6, the sintered alumina reacts with the fluorine gas 4 in the frame furnace, and the surface thereof becomes aluminum fluoride (AlF ₃ ). The chemical form of uranium contained in the nuclear fuel material 1 is UO ₂ , which reacts with fluorine as shown in Formula 3 to generate volatile UF ₆ .

  At this time, FP contained in the nuclear fuel material 1 also reacts with the fluorine gas 4 to become fluoride. The non-volatile fluoride generated in the frame 9 becomes a fluoridation residue 10, falls inside the frame furnace due to gravity, and is recovered as a residue by the residue recovery unit 11.

  On the other hand, the volatile fluoride generated in the flame 9 at 1200 ° C. to 1600 ° C. flows downward while diffusing in the flame furnace toward the inner wall surface of the flame furnace. Among volatile fluorides diffusing toward the surface of the inner wall of the flame furnace, semi-volatile fluorides having a relatively high boiling point gradually decrease in temperature due to the temperature gradient as they approach the wall surface, and are condensed into liquid or solid, or It condenses by contacting the surface of the aggregate 6 and being cooled.

  The condensed fluoride falls in the flame furnace by gravity and is collected as a residue. Therefore, the collected residue becomes a mixed residue 12 in which the fluorinated residue 10 and the aggregate 6 in which fluoride is condensed on the surface are mixed.

  If the nuclear fuel material 1 is fluorinated without supplying the agglomerate 6, the semi-volatile FP fluoride diffuses to the surface of the inner wall of the flame furnace, where it is cooled, condensed, and fixed.

Among the volatile fluorides generated in the flame 9, volatile FP fluorides that do not aggregate even at the temperature of the flame furnace inner wall surface are off-gas along with UF ₆ gas, O ₂ gas, and fluorine gas surplus in the fluorination reaction. 7 passes through the vent 13 and is exhausted from the residue collection unit 11. Thereafter, uranium, which is a nuclear fuel material, is recovered from the exhausted off gas 7, and the recovered uranium is reused as nuclear fuel.

  As described above, according to the embodiment of the present invention, when the nuclear fuel material 1 reacts with the fluorine gas 4 in the fluorination apparatus of the flame furnace type, the FP on the inner wall surface of the flame furnace is supplied by simultaneously supplying the aggregate 6. Fluoride adhesion can be suppressed, exposure risk at the time of work such as flame furnace replacement is reduced by reducing the radiation dose on the surface of the flame furnace, and FP fluoride adheres to the inner surface of the flame furnace and affects the operating conditions of the flame furnace It is possible to obtain the effect of preventing and reducing the adhesion of nuclear fuel material to the surface of the inner wall of the flame furnace.

  A second embodiment of the present invention will be described below with reference to FIG. The embodiment of the present invention is an example relating to a method and apparatus for fluorinating nuclear fuel material. The fluorination apparatus according to the present embodiment is shown in FIG. 2 and includes a nuclear fuel material inlet 2, a fluorine gas inlet 3, a flame furnace 8, a residue recovery unit 11, and a vent 13 as in the first embodiment. In addition, a gas inlet 14 is disposed in the frame furnace 8 instead of the aggregate inlet 5 of the first embodiment.

  The outline of mass transfer in Example 2 will be described below. The nuclear fuel material 1 will be described as a spent fuel, for example. As in the first embodiment, the nuclear fuel material 1 is supplied from the nuclear fuel material inlet 2 and the fluorine gas 4 is supplied from the fluorine gas inlet 3 to form a frame 9 and the fluorination reaction proceeds.

Similar to Example 1, uranium contained in the nuclear fuel material 1 reacts as shown in the chemical formula 3 to become volatile UF ₆ , and at the same time, FP contained in the nuclear fuel material 1 reacts with the fluorine gas 4 to volatilize. And semi-volatile, non-volatile fluoride.

  The non-volatile fluoride becomes a fluoridation residue 10 and falls inside the frame furnace due to gravity, and is collected as a residue by the residue collection unit 11. On the other hand, volatile and semi-volatile fluorides circulate downward in the flame furnace while diffusing toward the inner wall surface of the flame furnace.

In order to prevent the volatile fluoride from reaching the inner wall surface of the flame furnace due to diffusion, a gas 15 such as N ₂ gas, O ₂ gas, F ₂ gas, Ar gas is supplied from the gas inlet 14 simultaneously with the supply of the nuclear fuel material 1. To supply as a carrier gas. The gas 15 is supplied from the inside of the flame furnace 8 to the residue recovery unit 11 before the volatile and semi-volatile fluoride generated in the flame 9 diffuses in the gas and reaches the surface of the flame furnace inner wall. It adjusts with the shape and operating conditions of the flame furnace 8 so that it may exhaust with gas.

  Among the volatile fluorides, the semi-volatile fluoride having a relatively high boiling point gradually decreases in temperature due to the temperature gradient as it flows through the flame furnace, and is condensed into liquid or solid, or cooled in the residue recovery unit 11. Is condensed and collected as a residue.

  Therefore, the collected residue is composed of only the fluorination residue 10. If the nuclear fuel material 1 is fluorinated without supplying the gas 15, the semi-volatile FP fluoride diffuses to the surface of the inner wall of the flame furnace, where it is cooled, condensed and fixed.

Among the volatile fluorides generated in the frame 9, volatile FP fluorides that do not aggregate even at the temperature of the inner surface of the flame furnace are UF ₆ gas, O ₂ gas, fluorine gas surplus in the fluorination reaction, gas 15 At the same time, it passes through the vent 13 as off-gas 7 and is exhausted from the residue recovery unit 11.

  Thereafter, in the uranium refining process, only the FP fluoride is adsorbed on the adsorbent and separated from the off-gas 7. Uranium, which is a nuclear fuel material, is recovered from the offgas 7 from which the FP fluoride has been separated, and the recovered uranium is reused as nuclear fuel.

This uranium recovery can be achieved by, for example, circulating the off-gas 7 through an adsorption tower filled with sodium fluoride kept at 100 ° C., adsorbing only UF ₆ , and separating the gas 15, O ₂ gas, and F ₂ gas. To be implemented.

  As described above, according to the present embodiment, when the nuclear fuel material 1 reacts with the fluorine gas 4 in the flame furnace type fluorination apparatus, the gas 15 is simultaneously supplied to attach the FP fluoride to the surface of the inner wall of the flame furnace. Reduces exposure risk during work such as flame furnace replacement by reducing the amount of radiation on the surface of the flame furnace, prevents FP fluoride from adhering to the flame furnace inner wall surface and affecting the operating conditions of the flame furnace, nuclear fuel The effect of reducing the adhesion of the substance to the surface of the flame furnace inner wall can be obtained.

  A third embodiment of the present invention will be described below with reference to FIG. Example 3 of the present invention is an example relating to a nuclear fuel material reprocessing method when the fluorination apparatus of Example 1 described above is used. As shown in FIG. 3, the nuclear fuel material reprocessing method of the present embodiment is a fluorination step 16, an oxide conversion step 17, and a nitric acid dissolution step using the fluorination apparatus and fluorination method according to the above-described first embodiment. 19 and a solvent extraction step 22.

  Hereinafter, mass transfer in Example 3 will be described. The nuclear fuel material 1 will be described as a spent nuclear fuel, for example. The fluorination step 16 is a step of reacting the nuclear fuel material 1 with the fluorine gas 4 by the flame furnace type fluorination apparatus described in the first embodiment, in order to suppress the sticking of the FP fluoride to the surface of the inner wall of the flame furnace. Add agglomerate 6.

From the fluorination step 16, the off-gas 7 composed of UF ₆ , F ₂ , O ₂ , and FP fluoride, and the mixed residue 12 composed of the nonvolatile FP and the aggregate 6 are discharged. The off gas 7 is separated from UF ₆ from the remaining F ₂ and O ₂ after the FP fluoride is removed in the uranium purification. Because UF ₆ is reused as a nuclear fuel material is transferred to the uranium enrichment process.

  Since the mixed residue 12 contains uranium and plutonium which are nuclear fuel materials, a process for recovering these nuclear fuel materials is performed. Since the chemical form of most of the mixed residue 12 is fluoride, the chemical form is first converted from fluoride to oxide in the oxide conversion step 17 (hereinafter, the obtained oxide is referred to as “converted oxide 18”). . Oxide conversion is performed, for example, by supplying the mixed residue 12 to a gas-solid reaction apparatus such as a rotary kiln, blowing high-temperature steam into the gas-solid reaction apparatus, and reacting the mixture to separate fluorine as hydrogen fluoride gas (HF).

  The converted oxide 18 obtained in the oxide conversion step 17 is dissolved in the nitric acid solution in the nitric acid dissolution step 19. Nuclear fuel materials such as uranium and plutonium are dissolved and transferred to the solution 21. When the group 2 element fluoride shown in Table 2 is used as the aggregating material 6, the converted oxide dissolves in the nitric acid solution and moves to the solution 21. When the lanthanoid fluoride shown in Table 2 is used as the agglomerating material 6, this converted oxide partially dissolves in the nitric acid solution and partially precipitates as an insoluble residue 20. When the sintered alumina shown in Table 2 is used as the aggregate 6, the converted oxide does not dissolve in the nitric acid solution and precipitates as an insoluble residue 20. Undissolved residue is treated as radioactive waste.

  In the solvent extraction step 22, the solution 21 comes into contact with the nuclear fuel material extraction material, and only the nuclear fuel material U + Pu 23 is transferred to the extraction material and separated from impurities such as FP dissolved in the solution 21. U + Pu23 is reused as nuclear fuel. The solution 21 from which U + Pu23 is removed in the solvent extraction step 22 becomes waste 24, which is treated as radioactive waste.

  As described above, according to the present invention, when the nuclear fuel material 1 is reacted with the fluorine gas 4 in the flame furnace type fluorination apparatus as in the first embodiment, the agglomerate 6 is simultaneously supplied, and the nuclear fuel material is recycled. Processing can be performed.

  The present invention has the potential to be used in a method for fluorinating nuclear fuel material, an apparatus therefor, and a method for reprocessing spent nuclear fuel.

DESCRIPTION OF SYMBOLS 1 Nuclear fuel material 2 Nuclear fuel material inlet 3 Fluorine gas inlet 4 Fluorine gas 5 Aggregated material inlet 6 Aggregated material 7 Off-gas 8 Flame furnace 9 Frame 10 Fluoride residue 11 Residue collection part 12 Mixed residue 13 Vent 14 Gas inlet 15 Gas 16 Fluoride Process 17 Oxide conversion process 18 Converted oxide 19 Nitric acid dissolution process 20 Undissolved residue 21 Solution 22 Solvent extraction process 23 U + Pu
24 Waste

Claims (11)

  In a fluorination apparatus using a flame furnace for reacting nuclear fuel material and fluorine gas, a semi-volatile material is disposed at a position on the outer peripheral side of the flame furnace from the supply port of the nuclear fuel material and fluorine gas attached to the upper portion of the flame furnace. A nuclear fuel material fluorination apparatus comprising a mechanism for supplying a substance for entraining FP fluoride to a lower portion of the fluorination apparatus into the flame furnace.   2. The material according to claim 1, wherein the substance is an aggregating material that aggregates semivolatile FP fluoride, and the mechanism includes a condensing material inlet that supplies the condensing material downward into the frame furnace. A nuclear fuel material fluorination device.   2. The nuclear fuel material fluorination apparatus according to claim 1, wherein the substance is any one of a fluoride of a group 2 element, a fluoride of a lanthanoid, and aluminum oxide.   2. The nuclear fuel material according to claim 1, wherein the substance is a carrier gas that does not react with the fluorine gas, and the mechanism includes a gas inlet that supplies the carrier gas downward into the flame furnace. Fluorination equipment. 5. The nuclear fuel material fluorination apparatus according to claim 4, wherein a gas type of the carrier gas is any one of N ₂ gas, O ₂ gas, F ₂ gas, and Ar gas.   In a fluorination method in which a nuclear fuel material is reacted with fluorine gas in a fluorination apparatus using a flame furnace, the flame fuel material and fluorine gas are supplied from the nuclear fuel material and fluorine gas supply ports attached to the upper part of the flame furnace. A substance for entraining semi-volatile FP fluoride to the lower part of the fluorination apparatus is supplied into the flame furnace from a position on the outer peripheral side of the flame furnace from the supply port. The method of fluorinating nuclear fuel material, wherein the semi-volatile FP fluoride is caused to flow along with the material and flow downward in the flame furnace.   7. The substance according to claim 6, wherein the substance is an aggregating material that aggregates semivolatile FP fluoride, and the aggregated material is supplied downward into the frame furnace to aggregate the semivolatile FP fluoride. A method for fluorinating nuclear fuel material, comprising agglomerating a material and entraining the material downward.   7. The nuclear fuel material fluorination method according to claim 6, wherein the substance is any one of a fluoride of a group 2 element, a fluoride of a lanthanoid, and aluminum oxide.   7. The carrier according to claim 6, wherein the substance is a carrier gas that does not react with the fluorine gas, and the mechanism supplies the carrier gas downward into the flame furnace, and the semivolatile FP fluoride is supplied to the frame furnace. A method for fluorinating nuclear fuel material, which is accompanied by a downward flow of a carrier gas. 10. The nuclear fuel material fluorination method according to claim 9, wherein a gas type of the carrier gas is any one of N ₂ gas, O ₂ gas, F ₂ gas, and Ar gas.   The nuclear fuel material and the fluorine gas are supplied into the flame furnace through the supply port of the nuclear fuel material and the fluorine gas attached to the upper part of the flame furnace, and are reacted. An agglomerate that aggregates semi-volatile FP fluoride is supplied from a position on the outer peripheral side, and a non-volatile fluoridation residue generated by a fluorination reaction between the nuclear fuel material and the fluorine gas is supplied to the flame furnace. The agglomerated material is recovered as a mixed residue, and the mixed residue is reacted with water vapor to be converted into an oxide, and then dissolved, and the nuclear fuel material in the mixed residue is separated and recovered by solvent extraction. Reprocessing method for nuclear fuel material.

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