TW445459B - Method and device for chemical decontaminating for structural part of radiation handling facility - Google Patents

Abstract

This invention provides a method and device for chemical decontaminating for structural part of radiation handling facility which can chemically dissolve and remove a metal oxide of a radioactive material from the surface of a structural part of radiation handling facility installed in an atomic energy facility, such as a decontamination object like piping, machine, and structural part. Ozone gas having a high ozone concentration is generated by a solid electrolyte electrolytic process. An ozone solution is prepared by injecting the ozone gas into an acidic solution of pH 6 or below. The ozone solution heated at a temperature in the range of 50 DEG C to 80 DEG C is supplied to a contaminated object to oxidize and dissolve a chromium oxide film by an oxidizing dissolving process. The ozone solution used in the oxidizing dissolving process is irradiated with ultraviolet rays to decompose ozone contained in the ozone solution, the ozone solution is passed through an ion-exchange resin to remove ions contained in the ozone solution. An oxalic acid solution is supplied to the contaminated object to dissolve an iron oxide film by a reductive dissolving process. Oxalic acid remaining in the oxalic acid solution after the reductive dissolving process is decomposed by injecting ozone into the oxalic acid solution and irradiating the oxalic acid solution with ultraviolet rays, and ions contained in the oxalic acid solution is removed by an ion-exchange resin.

Description

< ^ '445-4 5 9 A7 B7 Printed by the Shellfish Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs V. Invention Description (1 > Background of the invention belongs to the technical field of the invention. The present invention relates to including attachment to atomic energy facilities, etc. The constituent elements provided in the radiation treatment facility, such as piping, machinery, structural elements, and other metal oxides of the radioactive material of the decontamination object are chemically dissolved and removed from the surface of the decontamination object. Chemical decontamination method and device》 Description of related technology In atomic energy facilities, piping, machinery, structural elements, and other decontamination objects that come in contact with fluids containing radioactive materials are attached to the surfaces that come in contact with the fluid to produce radioactive material-containing materials. Oxide film> The amount of radiation around the decontamination object is high, which causes the operator's radiation exposure to increase during periodic maintenance operations or disassembly operations when the atomic furnace is disposed of. The method for removing the oxide film is to use : Dissolves the metal base material of the oxide film or decontamination object, dissolves or peels the oxide in solution Methods, etc. Part of the chemical decontamination method that chemically dissolves or removes the oxide film is applied by the actual machine, which has a significant effect of reducing exposure. Until now, there have been various stainless steel parts of atomic energy facilities as decontamination objects. A chemical decontamination method has been proposed, and the known methods are a combination of a process of oxidizing and dissolving chromium oxide in an oxide film by an oxidizing agent and a process of reducing and dissolving an iron-based oxide that is a main component in the oxide film by a reducing agent. For example, in Japanese Patent Gazette Special Fair No. 3-1 0 9 1 9 (Please read the precautions on the back before filling out this!. ≫ -ο- ·. Bookmark --- line> This paper The standard is applicable to the standard A4 standard of Jianjia (4) 45 45 9 9 A7 B7 5. Description of the invention (2) The chemical decontamination method using permanganic acid as the oxidizing agent and dicarboxylic acid as the reducing agent is publicly disclosed. By using a low concentration Permanganic acid with high oxidation effect and dicarboxylic acids that can be decomposed into C02 and 112O, compared with the chemical decontamination methods so far, can reduce the amount of secondary waste. This method is used in decontamination of nuclear power generation facilities work There are already achievements in Japanese Patent Publication No. Sho 5 5-1 3 5 8 0'0 | It is described that an aqueous solution of dissolved ozone gas is used as an oxidant, and it is decontaminated with an organic acid and an modifying agent. A method for decontamination using a combination of liquids. Furthermore, Japanese Patent Application Laid-Open No. 9-1 15 1 7 9 8 describes the blowing of ozone gas into a solution containing a foaming agent to generate a bubble, and the bubble decontamination solution is sent. The method for feeding and decontaminating objects is described in a recent publication in which ozone gas is blown into a solution containing a foaming agent to generate a bubble liquid, and the bubble decontamination liquid is sent to a decontamination object for decontamination. In the chemical decontamination method by using permanganic acid and dicarboxylic acid, since the manganese component in the permanganic acid solution is recovered by the ion exchange resin, secondary waste caused by the decontamination agent is generated. However, ozone-based gas with strong oxidizing power * decomposes in water and water to produce various reactive oxygen species with oxidizing power. Utilizing this oxidizing force, an ozone aqueous solution that efficiently dissolves ozone gas in water, if it can dissolve the oxide film, will become a very effective decontamination method with minimal secondary waste due to oxidants. However, the concentration of the known ozone gas generated by the conventional silent discharge type ozone generator is as low as 1% or less, and the ozone concentration in the aqueous solution obtained by aerating the acidic solution is several p pm or less at room temperature. This paper size is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) i ---- 一 -------- il · (Please read the notes on the back of the praise before filling in this I. & gt l · Order · ι- 'Line · Printed by the Shellfish Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs *, Λ Α7 • 4454 5 q_si___: V. Invention. Explanation (3 > {锖 Read the precautions on the back before filling in this Page) In the oxidation treatment with an aqueous ozone solution of this concentration, compared with the conventional chemical decontamination method using permanganic acid, there is a problem that the removal performance of the oxide film is inferior. In addition, ozone is decomposed in water It is reduced. In the case of high temperature of the aqueous solution, the decay period of the dissolved ozone is short, and it may disappear in a few minutes. However, in the chemical decontamination method, the higher the temperature of the decontamination liquid1, the more the oxide film is dissolved. Because of the high decontamination effect, in order to shorten the overall working time, it is necessary to perform decontamination in a high temperature state as much as possible. "Because of the ozone depletion dissolved in aqueous solution, although agents such as foaming agents may be used to generate air bubbles. , In the state of ozone gas to maintain at However, in the sewage liquid, there may be a problem that a foaming agent becomes a secondary waste. Furthermore, the conventional chemical decontamination method by oxidation and reduction and dissolution is mainly applied to the stainless steel material part. Printed on the disclosure of the subject invention of carbon steel and other materials that are easily corroded by the chemical reagent metal base material. The invention was published by the Ministry of Economic Affairs, the Intellectual Property Bureau, and the Industrial Consumer Cooperative. The present invention was completed to solve the above problems. The purpose is to provide a chemical decontamination method and a device for a structural element of a radiation processing facility with high oxidation dissolution performance of an oxide film and a small amount of secondary waste, and an object of the present invention is to provide a decontamination agent that can be treated. Chemical decontamination methods and devices for organic acids with reducing power, such as oxalic acid and structural components of radiation treatment facilities for ozone exhaust. In order to achieve the above-mentioned object, the present invention provides a method for removing, including, attaching to, Zhang scale (used in China) Standard (CNS) A4 (210 X 297 male «) ~ ~ ": f'4 454 5 9 A7 B7 Member of Intellectual Property Bureau, Ministry of Economic Affairs Printed by a consumer cooperative V. Description of the invention (4) A method for oxidizing an oxide film of a radioactive substance of a decontamination object of a structural element of a radiation processing facility, comprising: supplying an ozone aqueous solution obtained by contacting ozone gas with an acidic aqueous solution to The above-mentioned object is an oxidizing and dissolving process for oxidizing and dissolving the above-mentioned oxide film. The P 臭氧 of the above-mentioned ozone aqueous solution is preferably 6 or less, more preferably 5 or 0, so that ozone of an oxidizing gas is dissolved in a desired water strip. · The aqueous solution can effectively dissolve and remove the oxide film on the surface of the decontamination object attached to or generated on the piping or equipment of the radiation treatment facility. Also, in the above-mentioned oxidation and dissolution project, the above-mentioned ozone aqueous solution is preferably at 50 ° C. ~ 90 ° C to the above-mentioned object >> It is preferable that the supply of the above-mentioned ozone gas be: a solid electrolyte as a boundary, an anode chamber on one side, and a cathode chamber on the other side. The anode formed by the catalytic metal in the anode chamber is used to electrolyze pure water, and the solid electrolyte electrolytic method for generating ozone from the anode chamber is used to An ozone decomposing the raw electrical device is obtained. · This method can also be set up: measuring the oxidation reduction potential of the above-mentioned ozone aqueous solution, and monitoring the oxidation-dissolving performance of the above-mentioned ozone aqueous solution. In addition, in this method, a reduction and dissolution process of supplying the decontamination liquid formed by an organic acid aqueous solution to the object and reducing and dissolving the oxide film can be provided. In this way, in the oxidizing and dissolving process, by reducing the ozone into C 0 2 and Η 20 in the reducing and dissolving process, organic acids with reducing power can be used as decontamination agents, respectively, and the production of decontamination agents can be reduced. Amount of secondary waste generated. < Please read the business matters on the back before filling in this! &&;; -r ^: nn I n If ϋ nnnn · 1 n · Λ—y This paper size applies to China National Standard (CNS) A4 (210 X 297) Public *) ^ '^ 445 45 9 A7 B7 V. Invention. Explanation (Furthermore, in this method, it can also be set up: after the above-mentioned reduction and dissolution engineering, the reducing agent decomposition project of the organic acid remaining in the above-mentioned organic acid aqueous solution, And a removal process for removing ions existing in the above-mentioned ozone aqueous solution or ions existing in the above-mentioned organic acid aqueous solution. In addition, the reducing agent decomposition process may include the following processes: ozone or hydrogen peroxide is added to the above-mentioned organic acid aqueous solution. And the process of irradiating ultraviolet or radiation to the above-mentioned organic acid aqueous solution. Instead of this, the above-mentioned reducing agent decomposition process can also be performed by irradiating light with titanium oxide and bringing the titanium oxide into contact with the above-mentioned organic acid aqueous solution. It is performed by the photocatalytic action of titanium oxide to decompose the above-mentioned organic acid. Also, in this method, it can be further provided that, after the above-mentioned oxidation and dissolution process, the above-mentioned odor Oxygen aqueous solution irradiates ultraviolet rays or radiation to decompose the oxidant oxidant in ozone solution. The organic acid aqueous solution used in the above-mentioned reduction and dissolution process can include organic salts in addition to organic acids. In the reduction and dissolution process For example, if a mixed solution of oxalic acid and the salt is used, chemical decontamination can be applied even to carbon steel parts that are easily corroded. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs (谙 Read the precautions on the back before filling in the book 1 ·} Λ) / Furthermore, according to a second aspect of the present invention, the present invention provides a decontamination device for removing an oxide film including a radioactive substance of a decontamination object attached to a structural element of a radiation processing facility, which is characterized by having : The first decontamination liquid circulation system of the first pump that circulates the decontamination liquid through the above decontamination object, and an ozone injection system for supplying ozone to the decontamination liquid in the decontamination liquid circulation system, and The pH adjusting agent supply device for supplying the pH adjusting agent to the decontamination liquid in the first decontamination liquid circulation system, and a paper ruler for the first descaling paper Applicable to China National Standard (CNS) A4 Regulations < 210 X 297 Gong > -8-" 44545 9 A7 _. _B7_ V. Description of the Invention (6 > Supply of decontamination liquid in the sewage circulation system An organic acid supply device that is an organic acid that is a reducing agent, a light irradiation device that irradiates light to the decontamination liquid in the first decontamination liquid circulation system, and removes the decontamination contained in the first decontamination liquid circulation system. Ion exchange device for ions in sewage liquid. The advantageous form of this decontamination device can be understood by referring to the dependent patent application items and suitable embodiments. '' Description of Appropriate Embodiments-The following describes the present invention with reference to the drawings. Appropriate implementation. FIG. 1 is a flowchart showing an example of the decontamination method of the present invention. The decontamination method shown therein includes: (A) supplying an ozone solution as a decontamination liquid to a decontamination object, and dissolving and removing the oxide film of the oxide film Dissolution process, and (B) decomposition process of oxidant decomposing ozonizer in ozone water barren solution, and (C) first removal process of removing dissolved components such as metal ions from the decontamination solution decomposed by ozone, and (D) An organic acid aqueous solution such as an oxalic acid aqueous solution is supplied as a decontamination liquid to a decontamination object, a reduction and dissolution process for reducing and dissolving an oxide film, and (E) a second removal process for removing dissolved components such as metal ions from the decontamination solution, and (F) Reducing agent decomposition process for decomposing organic acids in organic acid aqueous solution, and (G) Third removal process for removing dissolved components such as gold ions from the decontamination liquid in which organic acids are decomposed, and this paper standard applies China National Standard (CNS) A4 specification (210x297 public love) (锖 Read the precautions on the back before filling this page) ^ Order • 丨 丨 丨 丨 丨 丨 -line-Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs .tf n n n n n n Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs ^ '445 45 9 A7 B7 V. Description of the invention (7) (Η) The X process of discharging the decontaminated liquid which has been purified by 淸. Hereinafter, the above-mentioned processes will be described. I. Oxidation and dissolution process First, an acidic aqueous solution in which acid is more preferably added to water is prepared. The added acid is preferably an inorganic acid such as nitric acid. The "ρ Η" of the acidic aqueous solution is preferably 6 or less, and more preferably adjusted to 5 or less. "Next, the ozone gas is dissolved in the acidic aqueous solution to generate an acidic ozone aqueous solution, that is, a decontamination solution. By adjusting the acidic aqueous solution to the above pH, the amount of ozone dissolved in the acidic aqueous solution can be increased. Ozone is an oxidizing gas. If the ozone gas is dissolved in water or the above-mentioned acidic aqueous solution, the ozone gas is decomposed by a reaction of the following formulae (1) to (5) to generate various active oxygen species. 〇3 + OH · ^ Η02 + 0 ... (1) 〇3 + H〇2 ^ 2〇2 + OH ... (2) 〇3 + OH 〇2 + H2〇 ... (3) 2 HjO—〇3 + H2O ... (4) H〇2 + OH — 〇2 + HiO ... (5) Ozone and these active oxygen species can be clearly understood from the redox potentials shown in Table 1 below, with high manganese Compared with acid ions, it has strong oxidizing power. This paper size applies to China National Standard (CNS) A4 specification (210 X 297 mm) (Please read the notice on the back before filling in this 1) 丨 Order ------- line · ^^ 1 -10- 9 5 4 5 4 4 Α7Β7 V. Description of the invention (8) [Table 1] Electrode reaction potential / V vs. NHE OH + H * + e '= H2〇2.81 〇3 + 2 H + + 2e = O2 + H2O 2.07 H〇2 + 3 H + + 3e '= 2 H2O 1.7 Mn〇4 + 4H + + 3e' = Mn〇2 + 2H2 1.7 '' Then, the ozone solution prepared as described above was supplied to the decontamination object. In this way, the chromium oxide in the oxide film can be oxidized and dissolved by the oxidizing power of ozone and active oxygen. In addition, in the case where the aqueous solution is acidic to neutral and the redox potential is around 1 110 m V, the chemistry of chromium is Hd: r 〇4_, C r 〇42_ or its condensed C r 2〇72_ The form is very stable. Therefore, the chromium oxide C r 2 0 3 is considered to be dissolved in the solution by a reaction of the following formula.

Cr2Ch + 3Ch + 2 H2〇— 2CrCh2 '+ 4H + + 3〇2 C r 2 Ο 3 + 3 Ο 3 + Η 2 Ο-»C r 2 〇 72 + 2 Η + + 3 Ο 2 Employees of Intellectual Property Bureau, Ministry of Economic Affairs Printed by a consumer cooperative < Please read the precautions on the back before filling out this page > Attached to or generated in the metal oxide film on the surface of radiation processing facilities, such as piping, structural elements, etc. of atomic power plants. Chromium-based oxides are difficult to reduce and dissolve, but can be oxidized and dissolved by oxidation. Since ozone has a strong oxidizing power as described above, it can be suitably used as a stain remover for oxidative dissolution. In addition, while the ozone in the aqueous solution is consumed by the reaction, it will also be reduced due to its own decomposition. The solubility of the oxide film depends on the ozone concentration. In the oxidation and dissolution process, to continuously monitor the ozone concentration in the solution, it is necessary to moderately measure the paper size 97 2 X ο 21 / V to make M Ns) (c. 445 45 9 A7 B7 V. Description of the invention (9) It is best to control the amount of ozone injected into the solution if necessary. The monitoring of ozone concentration is best performed by measuring the oxidation-reduction potential of the aqueous ozone solution. Figure 2 shows the measurement. Result of ozone concentration in solution and redox potential. As shown here, the redox potential is positively related to ozone concentration | It is easy to monitor the ozone concentration in solution by monitoring the redox potential. Next, refer to The experimental results show the methods to improve the efficiency of the oxidation and dissolution engineering. C a-1) ρ 臭氧 of the ozone solution First, the experimental results regarding the dissolution characteristics of the oxide film according to the pH of the ozone solution are described. Add acid or salt to pure water at 50 ° C at 500 cm3, and prepare various aqueous solutions whose pH is adjusted to 3-9. Measure the solubility of ozone in the solution at a flow rate of 50 cm3 · m i η * " 1 with 4 v 0 1% ozone gas (hereinafter referred to as "aeration condition 1") in each aqueous solution. 'Also, a test piece (2 cmx 3 cmx 0.1) of SUS304 (JIS containing approximately 18% Cr and Ni approximately 8% Ni-containing stainless steel) as one of the constituent elements of the atomic furnace is prepared. cm) .. This test piece was immersed in high-temperature water that simulated the fluid conditions of the primary system of a boiling water atomic power plant (BWR) for 300 hours (hereinafter, this condition is referred to as "oxidation condition 1".), And an oxide film was formed on the surface. This test piece is immersed in the paper size of ozone supplied under the above-mentioned "ventilation condition 1". The Chinese national standard (CNS > A4 size (210 X 297 public love)) is applicable. ≪ Please read the health benefits on the back before filling in this i Economy Printed by the Ministry of Intellectual Property Office

Kn H ϋ 一 & 1 > ϋ n 1 I \\ ltnn D n ϋ nn I nnnn 1 n I 1 / -12 Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Invention. Explanation (10) in ozone water solution 2 hours. For comparison, the test pieces produced under the same conditions were immersed in an aqueous permanganic acid solution (temperature: 95 ° C, concentration: 0.03%) for 2 hours. Generally, the oxidizing solution is immersed, and among the constituents of the oxide film, although the weight of the oxidized dissolved component is reduced, the oxide becomes a higher oxidation state and the oxygen is combined, otherwise the weight is increased. Test after oxidation treatment The weight of the tablet is the combined result of these weight gains. It is not possible to determine the oxidative dissolution effect clearly. Therefore, after immersing the ozone or permanganic acid solution, the test piece is immersed in an 0.2%, 95 ° C oxalic acid aqueous solution. 1 hour (hereinafter, this condition is referred to as "reduction condition 1"), and the oxidizing solution and the reducing solution are impregnated to remove all dissolved oxides, and the weight loss of the test piece is measured. Figure 3 Series It shows the dissolved amount of the oxide film when it is oxidized in the ozone aqueous solution of each P 。. The dissolved amount of the oxidized film starts to rise from ρ Η 6 or lower, and it rises sharply below P Η 5, showing a high level. The dissolution performance of the manganic acid method is equal to or higher. The solubility of the oxidized film of the ozone solution in the same temperature condition, the higher the ozone concentration in the solution, and the lower the pH, the more the dissolution of ozone is promoted. Also, P氧化 The oxidation-reduction potential of an aqueous ozone solution below 5 is higher than the measurement result of the oxidation-reduction potential of 0.93% permanganic acid solution at 95 ° C 10.5 OmV. Based on the experimental results, it can be known that ozone The pH of the aqueous solution is preferably pH 6, more preferably above ρ Η 5. (1 -b) pH adjuster for ozone aqueous solution The paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) l · —) --------- ρ ------- k Order ------- line-o- (Please read the precautions on the back before filling this page) -13- "〖 4 45 45 9 Α7 Β7 V. Description of the invention (11) Next, the test results of the review of the PΗ regulator of the ozone solution will be described here. The PΗ regulator The representative objects are nitric acid and sulfuric acid of inorganic acids and oxalic acid of organic acids. First, nitric acid and sulfuric acid are added to pure water 5 0 0 c m3 'to become P Η 3 6 01C acidic aqueous solution according to the above. "Ventilation condition 1" is to ventilate ozone gas, and measure the dissolved concentration of ozone in the aqueous solution. The ozone concentration in the solution can be doubled in the case of using pure water at the same temperature (60 ° C) for ozone gas when using nitric acid or sulfuric acid. In addition, oxalic acid was added to an acidic aqueous solution of 50 ° C at 50 ° C in which pure water was 50 cm3, and ozone aeration was performed under "aeration condition 1" to measure the dissolved ozone concentration in the solution. The ozone concentration in the solution was re-odorous and the initial oxygen gas aeration was 2000 p pm. However, if the aeration of ozone gas is continued, the ρ 溶液 of the solution rises and the ozone concentration in the solution decreases. After 2 hours of ozone aeration, the pH of the solution increased to 3.5 and the ozone concentration in the solution decreased to 3 p pm. It can be inferred that the oxalic acid is decomposed by ozone, and the ozone in the solution is consumed for the decomposition of oxalic acid. Moreover, as the oxalic acid in the solution decreases, the pH of the solution increases, and the solubility of ozone decreases. An aqueous solution of ozone obtained by aeration of an aqueous solution of sulfuric acid and oxalic acid with ozone was used for the dissolution test of the oxide film. That is, for adding pure nitric acid and sulfuric acid in pure water at 60 ° C, oxalic acid aqueous solution and sulfuric acid aqueous solution adjusted to pH 3, and pure water in 50 ° C. The paper size applies Chinese National Standard (CNS) A4 specifications (210 X 297 male «〉 (Please read the precautions on the back before filling in this page) -ο ^ ------- P Order L ------- Line ..'- 'Λ Ministry of Economic Affairs Printed by the Consumer Property Cooperative of the Intellectual Property Bureau -14- A7 k: K445 4 5 9 V. Description of the invention (12) Add oxalic acid and adjust it to pH 2 aqueous oxalic acid solution. While immersing the SUS 3 04 test piece provided with an oxide film under the above-mentioned "oxidation condition 1" for 2 hours, the test piece was immersed in an aqueous oxalic acid solution of 0, 2%, and 9 for 1 hour ("reduction condition 1"). After all the oxidation and reduction reactions have removed the dissolved oxide, the weight loss of the test piece is measured. The result of 1 is shown in Figure 4. In Figure 4, the broken line corresponds to the vertical axis showing the ozone concentration, and the bar line corresponds to the display oxidation. The vertical axis of the dissolved amount of the film. As shown in the graph of FIG. The ozone solution obtained by dissolving ozone in sulfuric acid aqueous solution has about 1.5 times the dissolving effect of the oxide film compared with the case of using the permanganic acid aqueous solution. In contrast, when the ozone gas solution is used to dissolve the ozone gas, In the case of the obtained ozone aqueous solution, the dissolution effect of the oxide film is almost equal to that in the case of using the permanganic acid aqueous solution. From this, it can be understood that: ++ By adding inorganic acids such as nitric acid and sulfuric acid, the oxide film is oxidized and dissolved Excellent performance. However, in the case of decontamination of piping of atomic energy facilities, sulfuric acid or hydrochloric acid becomes the cause of stress corrosion cracking or pinhole corrosion of metal materials. The use of these things is not appropriate. The impact on metal materials is small and it is also itself Nitric acid with oxidizing power is more suitable as an additive. However, if nitric acid is used to make PΗ too low and metal materials are corroded, the pH during the oxidation treatment is expected to be above 3. In the case of using an aqueous ozone solution containing nitric acid, Removal process of dissolved metal ions (the first removal process (c) described at the beginning), nitrate < Please read the note ^^ on the back before filling in this 1 ·} Ή *-General Chinese National Standard (CNS > A4 Specification (210 X 297 mm) for paper size printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Online Economy -15- ^ • '44545 9 V. Description of the invention (13) < Read the precautions on the back first # · Fill this K ·) Ions (N03-) are ionized together with metal ions. Therefore, it becomes the source of secondary waste. On the other hand, in the case of oxidation treatment with an aqueous solution of permanganic acid, manganese is captured by the cation exchange resin in the form of Mη. 2 +. Comparative investigations usually use the nuclear power plant The exchange capacity of the ion exchange resin used (cation exchange resin: 1.9eq / 'L, anion exchange resin: 1.leq / L) is the basic case, and a permanganic acid aqueous solution of 0.03% is used as the oxidant, and the case of using The amount of exchange resin generated in the case where the ozone aqueous solution obtained by dissolving the ozone in the nitric acid aqueous solution of p Η 3 and p Η 4 is dissolved. In addition, the agent for this comparative test was used to recover Mn 2 + in the permanganic acid aqueous solution by using a cation exchange resin, and to recover N 0 3 ~ in the ozone aqueous solution by using an anion exchange resin. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. The results are shown in Figure 5. It can be clearly seen from FIG. 5 that for the exchange resin amount generated in the case of using a permanganic acid aqueous solution, the exchange resin amount generated in the case of using an ozone aqueous solution is 1/3, and in the case of P4, Is 1/3 0. Therefore, in the case of preparing an ozone water solution, even when an aqueous nitric acid solution is used, the amount of secondary waste generated can be reduced compared with the case where a permanganic acid aqueous solution is used. The pH adjusting agent may be a buffering agent. However, those with buffering capacity in the range of ρΗ3 ~ 4 are generally those containing organic acids such as "acetic acid-sodium acetate". If such a buffering agent is used, the decomposition of the organic acid in the buffering agent consumes ozone and oxidizes and dissolves. Performance will deteriorate. Based on the above test and review results, it can be clear that: ρ Η adjuster is more suitable to use inorganic acids, especially nitric acid is the most suitable. This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 cm) -16 · A7 f) M445 45 9 ___B7____ V. Description of the invention (14) (1-C) Temperature conditions for oxidation and dissolution engineering Test results on the temperature of the oxidation dissolution process. In the conventional chemical decontamination method using permanganic acid, the oxidation treatment and the reduction treatment are performed at a high temperature of 95 ° C, but as explained above, it shows acidic ozone at 50 ° C and a pH of 3 to 5. The aqueous solution has good dissolution properties of the oxide film. -Although the concentration of ozone dissolved in the aqueous solution becomes higher as the temperature becomes lower, the oxidation reaction rate of chromium oxide becomes higher as the temperature becomes higher. Therefore, it is considered that an appropriate temperature condition exists on a dissolved oxide film in which the dissolved concentration of ozone and the promoting effect of the oxidation reaction are balanced. Therefore, the temperature dependence of the dissolution characteristics of the oxide film in the oxidative dissolution process was investigated. After adjusting p Η to 3 to 5 with nitric acid, each temperature (40 ° C to 95 ° C) in an aqueous ozone solution soaked with the SUS 304 test piece containing the oxide film produced under the above "Oxidation Condition 1", and then subjected to the reduction treatment under the "Reduction Condition 1" above, and the measured film loss (oxidation) Membrane dissolution). The results are shown in FIG. 6. In FIG. 6, the unpainted curve corresponds to the vertical axis showing the dissolved amount of the oxide film, and the painted curve corresponds to the vertical axis showing the ozone concentration in the oxidation treatment solution. As can be understood from the curve of FIG. 6 In the solution with ozone concentration in all pH, the lower the solution temperature is, the higher the solution temperature is. However, the dissolved amount of the oxide film is the lowest at 40 ° C on the low temperature side. This is considered to be: at low temperature, even if the ozone concentration is high However, due to the low temperature, the oxidation reaction of chromium oxide cannot reach the standard of this paper (CNS > A4 < 210 X 297 cm). KI .-------------- ------ r ------- ^-ior (Please read the ii notice on the back before filling out this page) Printed by Shelley Consumer Cooperative, Intellectual Property Bureau, Ministry of Economic Affairs-17- ^ ^ '44545 9 A7. _._ B7_____ V. Description of Invention (15). (Please read the precautions on the back before filling in this page.) From the curve in Figure 6, you can understand that the solubility of the oxide. Film is in the temperature range of PH3 and PH4, 50 ° C ~ 80 ° C, ozone water solution. It is equal to or higher than an aqueous solution of permanganic acid at 95 ° C. Therefore, the oxidation treatment process is most effective in the temperature range of 50 ° C ~ 80 ° C. (1-d) Maintaining the ozone concentration in the solution during high-temperature treatment · Fig. 7 shows the temperature dependence of the oxidative dissolution performance of the chromium oxide in the ozone aqueous solution. It can be clearly seen from the curve of FIG. 7 that the solution of chromium oxide has the best dissolution effect at a temperature of 80 ° C. However, when the solution temperature is 80 ° C, the decomposition of ozone in the solution is promoted, and the dissolved ozone is reduced in a short time. Therefore, when the ozone solution is passed through the object to be decontaminated, the concentration of dissolved ozone in the decontaminated liquid is reduced, which may reduce the decontamination effect. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. Also, Figure 8 shows the historical changes in ozone concentration in the gas phase and in the liquid phase. As can be understood from the graph of Fig. 8, the ozone concentration in the gas phase is smaller than that in the liquid phase. Therefore, the ozone gas is injected into the decontamination liquid by means of a mixing pump, etc., so that more ozone than the amount that can be dissolved in the liquid coexists with the solution in the form of bubbles, and circulates it in the system. The decrease of the ozone concentration 'dissolution of the ozone gas in the bubble' can suppress the decrease of the ozone concentration in the solution. Furthermore, as shown in FIG. 9, the oxidation and dissolution process of an ozone solution using co-existing ozone gas with a fixed concentration and the reduction and dissolution process using an oxalic acid aqueous solution are combined to perform a secondary system from a boiling water atomic power plant. Paper size applies to China National Standard (CNS) A4 specification (210 X 297 male «) A7 ^ '445459 V. Description of the invention (16) {Please read the notes on the back before filling in this 1 ·) Decontamination results. It can be clearly understood from the curve of FIG. 9 that after the three-cycle decontamination of organic acid treatment (first cycle), ozone treatment + organic acid treatment (second cycle), ozone treatment + organic acid treatment (third cycle), The radiation energy of the test piece was as low as 1/1000 or less, and it was confirmed that the test piece had an excellent decontamination effect than the high-acid method. From the above, by supplying the decontamination solution in which the ozone aqueous solution and the ozone gas coexist to the decontamination object, a higher decontamination effect can be obtained. -(1-e) Suitable Ozone Generator Next, referring to Fig. 10, an ozone generator suitable for the implementation of the present invention will be described. The ozone generator is formed by an electrolysis device having a solid electrolyte 1 formed of an ion exchange membrane and the like and a solid electrolyte 1 sandwiched between the anode chamber 4 and the cathode chamber 5 provided on both sides. The anode 2 made of a catalyst metal is arranged in the anode chamber 4, and the cathode 3 is arranged in the cathode chamber 5. The Intellectual Property Bureau of the Ministry of Economic Affairs, Shellfish Consumer Cooperative, printed the supply of pure water 6 to the anode chamber 4 and the cathode chamber 5, and applied a DC voltage from a DC power source 7 between the two electrodes 2, '3. The following reaction occurs on the surface of the anode 2 to generate oxygen 8 and ozone gas 9. 2EiO 〇2 t + 4H + + 4e! 3H2〇 ^ 〇3 f + 6H + + 6e 'If you use the ozone generator shown in Figure 10, you can now produce a maximum of 20 v ο 1% concentration of ozone gas 9. This ratio can be obtained by the conventional silent discharge type ozone generator (this paper size applies Chinese National Standard (CNS) A4 specification (210 X 297 mm > -19- A7 j ': ^ 445 4 5 9 _._ B7___ V. Description of the invention (17) lvo less than 1%) is excellent • Therefore, the ozone gas 9 generated by the ozone generator shown in FIG. A high-concentration ozone solution. By using a high-concentration ozone solution, a high oxide film removal effect can be obtained. In the anode chamber 4, together with the ozone gas 9, an ozone solution 10 in which ozone is dissolved in pure water is also generated. This ozone aqueous solution 10 is directly supplied to the decontamination object, and the oxide film on the surface of the decontamination object can be oxidized and dissolved. On the other hand, the cathode chamber 5 and the hydrogen 1 1 are also generated to reduce the hydrogen dissolved in pure water. Aqueous aqueous solution 11. By supplying this reducing aqueous solution 11 to the decontamination object in the reduction and dissolution process (D), the components of the oxide film, such as iron oxides, which are soluble due to reduction, are dissolved. In addition, by using the hydrogen gas 11 generated by the cathode chamber 5, in the reduction and dissolution process (D), a part of the trivalent complex compound of iron dissolved in the decontamination solution can be reduced, which can improve the ion exchange resin that is easy to be replaced by poplar. Proportion of Divalent Mistake Compounds of Captured Iron "By this, in the second removal process (E), the radioactive material in the decontamination solution can be efficiently separated and captured with the Yang ion exchange resin, which can reduce the decontamination. The amount of radiation around it. I. Oxidation decomposition process After the oxidation and dissolution process is completed, the ozone in the used ozone solution is decomposed by ultraviolet or radiation. The reason for setting up this oxidant decomposition process is: first, the oxidation dissolution process Paper size applies to China National Standard (CNS) A4 (210 X 297 mm) l · --- .. I --------------- Order "------- (Please read the note § on the back before filling out this page) Printed by the Shellfish Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economy-20-Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economy f '4 45 45 9 A7 _ B7___ V. Description of the Invention (18) Process (A) moved to the first removal process (C) If the aqueous solution of residual ozone is passed directly to the ion exchange resin, the ion exchange resin may be deteriorated due to ozone. Furthermore, when it is moved to the reduction and dissolution process (D), the situation where ozone remains in the decontamination solution If an organic acid such as oxalic acid is added to the decontamination liquid, it is not economically consumed by ozone decomposition. That is, by setting up this oxidizing agent decomposition project, it is possible to achieve a long life of the ion exchange resin, and it is not necessary. In order to compensate for the loss of the reducing agent, the reducing agent is excessively added. In addition, due to the decomposition of ozone itself (refer to FIG. 8), this oxidizing agent decomposition process does not necessarily need to be set. Fig. 11 shows the results of experimentally confirming the decomposition effect of ozone in the solution by irradiating ultraviolet rays generated by a low-pressure mercury lamp to an ozone solution. As shown in Fig. 10, when ultraviolet rays were irradiated for about 2 minutes, the initial concentration of 3 · 6 ppm became 0 · 1 ppm or less in 2 to 3 minutes. In this way, by ultraviolet irradiation, the ozone in the solution is decomposed in a short time. II, the first removal process is in parallel with the oxidant decomposition process (B), or after the oxidant decomposition process (B), the decontamination solution (aqueous solution during or after ozonolysis) is passed through the ion exchange resin and will be dissolved by oxidation Process (A) Ions such as dissolved metal ions are separated and removed from the decontamination liquid. In this process, the chromate ion and the acid of the pH adjuster (the acid added during the production of the ozone solution) are recovered by the ion exchange resin. After decomposing the oxidant, I adjust the pH by decomposing the anion exchange resin (I read the precautions on the back and fill in this I ') -------- Order -------- Line: λ ry Λ! / The size of this paper is in accordance with the Chinese National Standard (CNS) A4 specification (210 χ 297 public love) -21-t! K445 4 5 9 A7 B7 V. Description of the invention (19) Acid of the agent or dissolved chromate ion, etc. The reason that the decontamination liquid becomes the clean ion-exchanged water * When it is moved to the next reduction and dissolution project (D), you can directly put the reducing agent reagent such as oxalic acid into the solution. It was used as it is for the next reduction and dissolution process (D). (D) Reduction and dissolution process' Next, quantitatively add an organic acid with reducing power, preferably oxalic acid, to the solution purified by the first removal process (C), preferably oxalic acid, to prepare an oxalic acid aqueous solution. Sewage. The concentration of the oxalic acid aqueous solution is suitably about 0.2% by weight. This aqueous oxalic acid solution was heated to 80 ° C or higher, and was supplied to a decontamination object to dissolve an iron-based oxide as a main component of the oxide film. By an organic acid such as oxalic acid, the iron-based oxide is dissolved by the following reaction.

Fe2〇3 + (COOH) 2 + 4H + ^ 2Fe2 + + 3H2〇 + 2C〇2 In this way, the oxidation and dissolution process (A) and the reduction and dissolution process (D) are combined. The oxidation and dissolution process (A) can remove chromium oxide, The reduction and dissolution process (D) can remove iron-based oxides and efficiently remove the oxide film. However, although this decontamination method mainly targets structural elements made of stainless steel, the material of the structural elements of the atomic furnace In addition to stainless steel, carbon steel is also included. The corrosion resistance of carbon steel is low. 'Due to the organic acid of the stain remover, the base material may be corroded. Therefore, when the decontamination object contains carbon steel, it is best to use an oxalic acid and oxalate solution in the reduction and dissolution process. As a result, due to the buffering effect of P Η, the Chinese paper standard (CNS) A4 (210 X 297 public love) is applicable to the paper size of the same density (please read the "Notes on the back side before filling in this I.)- — — — In— illm! Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs and printed by the Shelley Consumers’ Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 45 45 s A7 ___B7__ 5. Description of the invention (20) The pH of the oxalic acid solution is maintained relatively high Corrosion of carbon steel can be suppressed. Figure 12 shows: In the case of reduction and dissolution, the use of 0.2% oxalic acid aqueous solution in the decontamination solution, and the use of 0.2% oxalic acid and 0 in pure water. Comparison results of the amount of carbon steel corrosion in the case of an aqueous solution formed by 3% calcium oxalate. Although the decontamination performance is the same in both cases, compared with the case where an aqueous oxalic acid solution is used alone, in the case where a mixed aqueous solution of oxalic acid / calcium oxalate is used, the amount of corrosion of carbon steel is reduced to about 1/3. (E) Second removal process Next, the decontamination solution (aqueous oxalic acid solution) used in the reduction and dissolution process (D) is passed through a cation exchange resin. In this process, the dissolved cations of F e 2 1 or C 0 + of the radionuclides are removed from the decontamination solution (F). The reducing agent is decomposed. Next, the cations are removed in the second removal process (E). Ozone is added to the oxalic acid aqueous solution or ozone aqueous solution is added, and the ultraviolet ray is irradiated to decompose the oxalic acid remaining in the liquid into CO 2 gas and water. That is, in the case of decomposing oxalic acid by irradiation with ozone and ultraviolet rays, the solution remaining after the decomposition is water, and no secondary waste caused by oxalic acid and its decomposing agent will be generated. By setting up the reducing agent decomposition project, in the subsequent third removal process (G), it is possible to prevent most of the exchange capacity of the anion exchange resin. The paper size is applicable to the Chinese National Standard (CNS) A4 specification &lt; 210 X 297.厘) — 丨 — 1 丨 丨 丨 丨 丨 丨 丨 ^^ it 丨 __Order—line (锖 Read the notes on the back first, and then write 1 ·) -23- Printed by the Intellectual Property Bureau Staff Consumer Cooperatives of the Ministry of Economic Affairs Preparing β ^ M445 δ ^ -_β7_ 5. Description of the invention (21) Points are consumed by the reducing agent. In addition, in this reducing agent decomposition process, ozone can also be replaced, and peroxide water can be added in addition to ozone, instead of irradiating ultraviolet rays, and irradiating radiation outside ultraviolet rays. Figure 13 shows the experimental results of aeration of ozone in an oxalic acid aqueous solution and irradiation of ultraviolet rays to decompose oxalic acid. "Here, a 0.2% oxalic acid aqueous solution with 0.8 dm3_mi η_M was given a total of 0. 7 v0 1% of ozone gas. 0W high-pressure mercury lamp irradiates ultraviolet rays. Compared with the case of irradiating ultraviolet rays alone, if ozone is used, the decomposition rate of oxalic acid is increased, and the organic carbon is reduced to 10 P pm or less in 4 hours. In addition, if a higher concentration of ozone gas is used, the decomposition time can be further shortened. In addition, oxalic acid can also be decomposed by photocatalyst * of titanium oxide stimulated by light irradiation. Titanium oxide is an η-type semiconductor. "When excited by light with a band gap or higher energy, electrons and holes are generated inside the hole." This hole has strong oxidizing power. In the case of contact with water, water due to The holes are oxidized to produce hydroxy free radicals (: 0H) with strong oxidizing power. The titanium oxide excited by the light is in contact with the organic acid solution, and the organic acid is oxidized and decomposed by the hole of the titanium oxide or the hydroxyl radical generated by the reaction with the hole. The band gap of titanium oxide is about 3.2 eV, which is equivalent to a wavelength of about 3 8 Omm. By irradiating light in a wavelength range below ultraviolet, laser, and the like, the titanium oxide can be oxidized. Figure 14 shows the experimental results of the decomposition of organic acids by irradiating ultraviolet (18 5 nm, 25 4 nm) titanium oxide generated by a low-pressure mercury lamp. As can be clearly seen from the curve in Figure 14, the organic carbon concentration is about 5 small paper sizes. The Chinese National Standard (CNS) A4 specification (210 X 297 mm) is applicable. (Please read the notes on the back of the page before filling in this page.) ) 〇: Order _l · ------- line ο -24- ^ 445459 A7 __.__ ^ B7_____ 5. In the description of the invention (22), it can be reduced to less than 1 /. 1 0 of the initial concentration. In addition, if ozone is used, organic acids can be more effectively decomposed. (G, H) After the third removal process and discharge process After the reducing agent decomposition process (F), the decontamination solution contains a little residual oxalic acid and dissolved metals. These solute components can be separated by passing the decontamination solution to the cation exchange resin and the anion exchange resin. 8-4 In the above processes (A) to (F), the radioactive energy concentration and the spatial radiation amount in the decontamination solution can be measured at the same time. Wait until necessary. After fully confirming that the oxide film has been discharged, the decontamination liquid is discharged (discharge process (Η)). In addition, the waste liquid discharged in the discharge process is in a state close to ion-exchanged water, and drainage is possible. The waste liquid is discharged to the liquid waste treatment system already installed. In the above description, although the oxidation and dissolution process (A) is preceded by reduction The dissolution ID process (D) is performed, but the process sequence is not limited to this. In order to remove the iron-based oxide, which is the main component of the oxide film, the dissolution T process (D), the second removal process (E), and The reducing agent decomposition process (F) is also effective before the oxidation and dissolution process. In addition, if a series of projects (A) to (G) are carried out at the same temperature conditions of 50 ° C to 8 ° C, the decontamination performance is good, and 'the temperature of the solution is not necessary to be raised or lowered between each project, and it can be continuous Moving the ground to the next project will shorten the operation time and reduce energy consumption. Device for implementing decontamination method The paper size is applicable to Chinese National Standard (CNS) A4 specification (210 X 297 male cage) (Please read the precautions on the back before filling this page) -------- 丨 Order · * ^! ---- line-CIV · Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs -25- Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs j ^ 454〇9 44545 9 a7 ___; __ B7_ V. Description of the Invention (2) Next, the device for implementing the above-mentioned decontamination method will be described. In Fig. 15, the decontamination object 22 is a radiation processing facility, such as a pipe attached to an atomic furnace or a furnace equipment, and the like, from one end to the other One end of the decontamination liquid 2 4 piping or machinery, for example, the heat exchanger is m ° in Figure 15, the reference number 2 5 is a buffer bucket used to store decontamination liquid 2 4. Connect to the buffer bucket 2 5 to remove The decontamination object 2 2 flows into and out of the decontamination liquid- 2 4 decontamination liquid circulation system 4 1. The decontamination liquid circulation system 41 has: the decontamination liquid 2 4 flows out from the bottom of the buffer tank 25 and is supplied to the decontamination object The supply pipe 4 2 of the object 2 2 and the decontamination liquid circulating in the decontamination object 2 2 are returned from the upper end of the buffer tank 25 The return piping 4 3 in the buffer tank 2 5. The supply piping 4 2 sequentially installs a circulation pump 3 2 from the upstream side to the downstream side. The heater 2 6 has a light irradiation device and an ion exchange unit 2 7 ′. Purification system 4 4. The ozone injection system 4 5 is connected to the buffer tank 2 5 through the ozone injection pipe 46. The ozone injection system 4 5 is composed of an ozone generator 2 8 and a mixing pump 2 9. The suction of the mixing pump-2 9 The side is connected to the bottom of the buffer tank 25 through a communication pipe 47. The pH adjusting agent supply device 31 and the organic acid supply device 23 are connected to the upper part of the buffer tank 25. Next, the function will be described. The pure water prepared in the buffer tank 25 is supplied with an organic acid, such as oxalic acid, from an organic acid supply device 23 to generate an aqueous solution of oxalic acid with a predetermined concentration, that is, a decontamination solution. This aqueous solution of oxalic acid is passed through the circulation pump 3 2 to the paper. Standards apply to China National Standard (CNS) A4 (210 X 297 mm) ----- I --------- I--Order ------- Line-C3- &lt; Please read first t # · Notes on the back please fill in this! -26- Printed by the Shellfish Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs' M445459. A7 _; _ B7___ 5. Description of the invention (24) Supply piping 4 2 to the decontamination object 22 and return the oxalic acid aqueous solution passing through the decontamination object 22 to the buffer barrel 25 through the piping 4 3 to circulate it. 》 Again, at this time, the oxalic acid water. Solution is heated to a predetermined temperature by the heater 26. As a result, the iron oxide in the oxide film containing the radioactive substance attached to the surface of the decontamination object 2 2 is It is dissolved by reduction reaction, acid dissolution, and chelation (the above corresponds to the reduction and dissolution process). -Cationic ions such as iron or radioactive nucleus cobalt dissolved in an oxalic acid aqueous solution are separated and recovered by a cation exchange resin (not shown) provided in the ion exchange section 27 (above • corresponding to the second removal process). Next, the ozone gas generated by the ozone generator 28 is injected into the aqueous oxalic acid solution by the mixing pump 29, and the light (ultraviolet rays) is irradiated to the aqueous oxalic acid solution with the light irradiation device 30. As a result, oxalic acid is decomposed into CO2 gas and water (above, corresponding to the reducing agent decomposition process). Furthermore, the separation of dissolved metal ions and the like can be performed in parallel with the decomposition of oxalic acid. Next, the decontamination solution decomposed by oxalic acid is passed through the ion exchange section 27 of the decontamination solution purification system 4 4 to remove the dissolved components remaining in the decontamination solution (the above corresponds to the third removal process). In this state, the decontamination liquid becomes clean water close to ion-exchanged water. Next, a pH adjusting agent such as nitric acid from the pH adjusting agent supply device 31 is added to the decontamination solution in the buffer tank 25 to adjust the decontamination solution to a pH of 5 or less. Furthermore, the ozone generated by the ozone generator 28 is adjusted. The gas is injected into the buffer tank 2 5 through the ozone injection piping 4 6 by the mixing pump 29, and an acidic ozone aqueous solution is generated. The decontamination liquid is circulated by the paper standard of the paper using the Chinese National Standard (CNS &gt; A4 Specification &lt;; 210 X 297 Public Love &gt; L ---- Γ --------------- Order l · ------- line—0 &quot; (Please read the first Please fill out this note! -27- Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 4 45.45 ο Α7 __._ Β7_ V. Invention. Explanation (2 sets 3 2 through supply piping 4 2 and return piping 4.3 to make it Circulate and supply the decontamination liquid, ie, the ozone water solution, to the decontamination object. The decontamination liquid is adjusted to a predetermined temperature by the heater 26. As a result, the decontamination liquid is contained on the inner surface of the decontamination object 22. The chromium oxide in the oxide film of the radioactive material is oxidized and dissolved (above, corresponding to the oxidative dissolution project). Also, in this project | 在An oxidation-reduction potential measuring device is installed at the inlet or outlet of the polluted object to monitor the oxidation-reduction potential of the ozone aqueous solution, and based on the monitoring result, the amount of ozone injected into the decontamination solution is appropriately controlled by an appropriate control device. The decontamination liquid is circulated, and the ultraviolet light is irradiated by the light irradiation unit 30 to release the ozone in the contamination liquid (the above * corresponds to the oxidant decomposition process). Next, the decontamination liquid decomposed by ozone is passed to the ion exchange unit 27. The anion exchange resin (not shown) dissolves and removes metal ions such as chromic acid ions and nitric acid ions dissolved in the decontamination solution (above, + corresponds to the first removal process). The radiation energy concentration and the amount of space radiation, etc., are repeated as necessary to perform the above-mentioned reduction and dissolution engineering, oxidation dissolution engineering, and removal engineering. In addition, by properly performing the removal process, the decontamination waste liquid becomes clean, and the decontamination liquid after decontamination is completed The waste liquid can be discharged to the waste liquid treatment system already installed in the facility of the nuclear power plant. Next, the decontamination device will be described with reference to FIG. 16. Other examples. In this example, the shroud 3 3 installed in the pressure vessel of the atomic furnace and the primary cooling material recirculation system piping 4 8 connected to the shroud 3 3 are installed in This cooling material recirculation is piping 4 8 of the recirculation pump 4 9 This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (Please read the unintentional matter on the back before filling in this 1 ·). * IIIIII 1 · 1 · 1 — — — — — — ^ / ΓίνΓ — — — — — -28- ^ 45459 a7 ___, _B7__ V. Description of the invention (2ί) is the object of decontamination. This example is characterized in that the covering ring 3 3 of the container-like object is also used as a buffer tank. The cover ring 3 3 is connected to the same decontamination liquid circulation system 41 as shown in FIG. 15. It is also possible to use a mounting portion (not shown) provided in the primary piping 48 to connect the decontamination liquid circulation system 41 to the cover ring 3 3. In the decontamination liquid circulation system 41, a heater 26, a true oxygen injection system 45, and a decontamination liquid purification system 44 are provided in the same manner as shown in FIG. The decontamination liquid filled in the covering ring 33 is circulated in the decontamination liquid circulation system 41, and ozone gas is injected through the mixing pump 29. The decontamination liquid 24 is heated to a predetermined temperature by the heater 26. In this example, a pH adjusting agent supply device 31 and an organic acid supply device 2 3 are connected to the covering ring 3 3 of the decontamination object, and the pH adjusting agent and the organic acid are adjusted in the covering ring 3 3. In the system of this example, decontamination can also be performed in the same order as the order of the device configuration in FIG. 15. In the decontamination treatment, the decontamination liquid is circulated in the cooling material recirculation system piping 4 8 by the recirculation pump 4 9, and the recirculation pump 4 9 and the recirculation system can be simultaneously performed not only by covering the loop 3 3. Decontamination of piping 4 8 As shown in FIG. 17, a bypass pipe 5.0 is provided beside the outlet side of the ion exchange unit 27 and the inlet side of the heater 26 which is connected to the piping constituting the decontamination cycle / system 41. Also, as shown in FIG. The pump 51 can be set by the wild pipe 50. With this configuration, the agitation of the decontamination liquid 2 4 in the covering ring 3 3 is promoted *, thereby improving the decontamination effect. Next, another example of the decontamination device will be described with reference to FIG. 18. In this example, the internal dimensions of the cooling material circulation pump 3 4 of the boiling water atomic power plant are in accordance with China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling in this (Page) Order ------- Line Ό ~-Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economy -29- A7 44S45g · ___B7_ V. Description of Invention (27) (Please read the notes on the back before filling in this I ·) and the inner surface of the ascending pipe 35 are decontamination objects. A pump 34 is connected above the horizontal portion of the rising pipe 35. The ascending piping 35 extends from the pump 34 to both sides in the horizontal direction, and stands on both sides in the vertical direction. A first mounting portion 36 and a second mounting portion 38 are provided at positions where the pumps 34 of the ascending pipe 35 are separated from each other. At these installation parts 3, 6 and 3, respectively, the two ends of the decontamination liquid purification system 4 are connected. 4 In the decontamination liquid circulation system 41, the same as shown in Fig. 1 is provided. | The heater 2 & Injection system 45 and decontamination liquid purification system 44. In addition, in this example, since the decontamination object cannot be used as a buffer tank for medicine adjustment, the pH adjusting agent supply device 31 and the organic acid supply device 23 are connected to the pipes of the decontamination liquid circulation system 41. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. In this example, the first pipe 3 7 and the second pipe 3 8 are provided with the first pipe 3 7 and the first pipe connected to the decontamination liquid circulation system 41. 2 tubes 39. The first and second pipes 37 and 39 are inserted into the pipe 35. Then, while the decontamination liquid is filled in the pipe 35 through the first pipe 37, the decontamination liquid is discharged through the pipe 35 through the second pipe 39, and the decontamination liquid is circulated in the decontamination object. In addition, the water in the piping 35 for the decontamination liquid is located in the circulation process, and is maintained at a height at which the decontamination liquid is filled inside the cooling material circulation pump 34. Thereby, the decontamination cooling material circulation pump 34 and the rising pipe 35 can be simultaneously performed. In addition, in the system of this example, the decontamination is also performed in the same order as that of the apparatus configuration of FIG. Next, another example of the decontamination device will be described with reference to FIG. 19. In this example, the decontamination object 40 is assumed to be a component that can be removed by an atomic energy machine. In this example, the buffer bucket 25 is also used for pharmaceutical adjustment and this paper size applies the Chinese national standard &lt; CNS &gt; A4 specification &lt; 210 X 297 public love> -30-^ 445 45 9 A7 B7 V. Description of the invention ( 2δ) Purpose of impregnation of decontamination objects. Decontamination objects 40 include, for example, machines and components such as rotating bodies of cooling material recirculation pumps, etc., which cannot circulate decontamination liquid. In the system of this example, the decontamination is also performed in the same order as that of the device configuration of FIG. 15. Next, another example of the decontamination device will be described with reference to FIG. 20 * FIG. 2 ◦ The system shown in FIG. 15 differs from the device shown in FIG. 15 in that an ozone exhaust device 53 and an exhaust device 54 are additionally provided. · In the case of oxidative dissolution process or reducing agent decomposition process, the remaining ozone not consumed by the reaction is discharged as exhaust gas, for example, it is necessary to be suitable for the limit of ozone concentration (0.1 ppm in Japan) 〇Therefore, a gas storage unit is provided in the decontamination device system, and the ozone gas trapped in the gas storage unit is passed through the ozone exhaust treatment device 53, which is decomposed and discharged. The ozone exhaust treatment device 53 is effective by using a filter formed of activated carbon or a metal catalyst. In the case of a low-concentration ozone gas of the order of 10 p pm, an activated carbon filter is suitable. Fig. 21 shows the change over time of the decomposition effect of low-concentration ozone gas by a honeycomb type active carbon filter. As can be clearly seen from FIG. 21, even if continuous aeration is performed for 300 hours, 80% of the aerated ozone can be decomposed. When the ozone concentration in the exhaust gas is at a high concentration above 100 OPPm, if an activated carbon filter is used, heat generation due to the decomposition reaction may damage the function of the activated carbon filter. In this high-concentration ozone treatment, metal catalyst filters are effective. Figure 2 2 shows the diachronic effect of the high-concentration ozone decomposition effect through the metal oxide catalyst filter. Make your paper size applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 male *) (please read the back first) (Please note this page before filling in this page) -------- Order ------- Printed by the Shell Property Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Employee Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs &quot; 4 454 5 9 a7: _: ____ B7___ V. Description of the invention (29) In the case of a catalyst filter with a metal or other metal oxide carried on an inorganic wearing body such as alumina, the decomposition effect is high, even if the ventilation is more than 4,000 hours , The concentration of ozone gas discharged is below 0.01 P. pm. Also as shown in Figure 2 3 | The higher the ozone concentration of the treatment object, the more the reaction heat of decomposition will be generated, but in the case of metal catalyst filters, the temperature will increase the catalyst activity and the decomposition efficiency will increase. . Therefore * The ozone exhaust processor is set according to the ozone gas concentration, and it can be safely exhausted from the system of the decontamination device. Next, another example of the decontamination device will be described with reference to Fig. 24. As shown in Fig. 24, an oxygen gas outlet pipe 55 is connected to the outlet side of the ozone exhaust treatment device 53. The oxygen gas outlet pipe 5 3 is connected to the coupling catalyst device 5 6, and the cathode chamber 5 of the ozone generator 2 8 is connected to the hydrogen outlet pipe 11, and the hydrogen outlet pipe 58 is connected to the connection catalyst. The device 5 6 β is combined. A drain device 17 is connected to the outlet side of the catalyst device 56. The exhaust device 54 is omitted. The ozone generator 28 is a device using the constitution shown in FIG. The other structures are the same as those of the device of FIG. In the ozone generator 28 of the water electrolysis method, hydrogen gas is generated from the cathode chamber 5. On the other hand, the ozone exhaust gas generated in the decontamination system is decomposed into oxygen gas. The oxygen gas discharged from the ozone exhaust treatment device 5 3 and the hydrogen gas generated from the cathode chamber 5 of the ozone generator 2 8 are introduced into the combined catalyst device 5 6, and the catalyst becomes “Η2 + 1 / 202— Η2〇”. The reaction can be combined into water. As the catalyst, a wearer who carries precious metals on alumina, activated carbon, or the like can be used. The water produced by combining the catalyst device 5 and 6 is used to drain the paper. The paper size applies the Chinese National Standard (CNS) A4 specification (210 * 297 mm) (please read the precautions on the back of the stew before filling this page)- -------- Order ---- line-32- &gt; ^ 4454 5 9 A7 ___ B7 V. Description of the invention (3d) B5 7 is discharged * According to the present invention, it can be discharged in a safer form Ozone and Hydrogen Gas "Next, another example of the decontamination device will be described with reference to Figs. In this example, for the system shown in FIG. 15, only one end of the ozone exhaust system 5 2 is connected to the upper part of the buffer tank 21, and the other end of the ozone exhaust system 5 2 is connected to the ozone injection system 45. The part on the suction side of 9 is different. "· In the case of oxidizing and dissolving process or reducing agent decomposition process, the ozone gas generated by the ozone generator 28 is injected into the buffer tank 25. Unreacted ozone gas stays in the buffer plant. 2 5 and the decontamination liquid circulation system 4 1 inside 0. In this example, a gas storage section C is provided in a part of the buffer tank 2 5 (not shown), and the part is discharged through the ozone exhaust system 52. The reaction ozone gas returns to the upstream of the mixing pump 29 and is injected into the buffer tank 25 again by the mixing pump 29. In this way, exhaust gas containing ozone can be effectively used. Also, in the above description, the case where the decontamination object is a structural element of a radiation processing facility has been described. However, the structure of a structural element of a facility that processes radiation or radioactive substances such as medical equipment or non-destructive inspection equipment is described. In the case of decontamination, it goes without saying that the present invention is also applicable. Brief Description of the Drawings Figure 1 is a flowchart illustrating a chemical decontamination method according to the present invention. Figure 2 shows the ozone concentration and redox potential in the ozone solution. This paper uses the Chinese Standard for Household Standards (CNS) A4 (<210 * 297 mm) (Please read the precautions on the back before filling this page>) Ministry of Economic Affairs, «printed by property property BKj-consumer cooperatives J · _ ·« ϋ fc-i 1 iw It n I ϋ BI nn I IK It nnnnn ϋ n 1 ^ 445 4 5 9 A7 B7 V. Description of the invention (31 ). Figure 3 is a graph showing the pH dependence of the solubility of the oxide film in the ozone solution a. Figure 4 is a graph showing the ozone concentration and the solubility of the oxide film in the ozone solution with the P Η regulator. Figure 5 It is a graph showing the amount of secondary waste produced by different oxidants. * Figure 6 is a graph showing the temperature dependence of the ozone concentration in the ozone solution and the dissolved amount of the oxide film through the ozone solution. Figure 7 is the ozone solution The temperature dependence curve of the ozone concentration in water and the amount of chromium oxide film dissolved in an aqueous ozone solution. Fig. 8 is a graph showing the change over time of the ozone concentration in the gas phase and the liquid phase. The decontamination effect curve chart of Ming's chemical decontamination method. Fig. 10 is a model diagram showing the composition of an ozone generator by solid electrolyte electrolytic method. Fig. 1 1 is a graph showing the decomposition effect of ozone by ultraviolet rays-Fig. 12 It is a graph showing the amount of corrosion of the base material of carbon steel caused by the difference of the additives used in the reduction and dissolution process. Fig. 13 is a graph showing the decomposition effect of oxalic acid by ozone and ultraviolet rays. Curves of the decomposition effect of organic acids. This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm). Please read it on the back of the page and fill in this page. -Printed by the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs &quot; m445 45 9 'a? __.__ B7___ V. Description of the invention (3 photos Figure 1 5 is a system diagram showing a chemical decontamination device according to the present invention. Figure 1 6 Fig. 17 is a diagram showing another form of the chemical decontamination device. Fig. 17 is a diagram showing another form of the chemical decontamination device. Fig. 18 is a diagram showing another form of the chemical decontamination device. Its morphological system diagram 0, Fig. 19 is a diagram showing another form of chemical decontamination system. Fig. 20 is a diagram showing another form of chemical decontamination system. Fig. 21 is a diagram showing ozone by activated carbon. Decomposition effect curve chart. Figure 22 is a graph showing the ozone decomposition effect by a metal catalyst. Figure 2 3 is a graph showing the calorific value of the oxygen oxidation reaction by a metal catalyst. Figure 2 4 shows chemical removal System diagram of a pollution decontamination device. Fig. 25 is a system diagram showing a chemical decontamination device according to the eighteenth embodiment of the present invention. ： ..-'Symbol Explanation 1 Solid Electrolyte / 2 Anode, 3 Cathode 4 Anode Chamber 5 Cathode Chamber' This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) ί Please read the notes on the back first Fill out this page again) -.I ---- -Order.! --- 1 · Line-35- Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs ^ 454S 3 'A7 _._ B7 V. Description of the invention (33) 7 DC power supply 2 2 Decontamination objects 2 3 Organic acids 2 4 Sewage liquid 2 5 Buffer bucket 2 6 Heater 2 7 Ion exchange unit 2 8 Ozone generator 2 9 Mixing pump 3 0 Light irradiation device 3 3 Cover PM 5 5 Ozone exhaust treatment device 5 6 Combine catalyst &lt; please first Read the notes on the reverse side and fill in this page) rw ·· ———— Order ---- ills _ ΓΛ This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) -36-

Claims (1)

®Clearance I expressly. Will this case be revised after 1 £? | :: ^^ Quality Contents Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs? 4 4 4 4 Patent Application No. 8122567 Chinese Application for Patent Scope Amendments to the Republic of China, March 6, 2006. Application for Patent Scope (1. A kind of chemical decontamination method for the components of radiation treatment facilities. It is a kind of chemical decontamination method. A method for removing an oxide film containing a radioactive substance including a decontamination object attached to a constituent element of a radiation processing facility, the method includes: supplying an ozone aqueous solution obtained by contacting ozone gas with an acidic aqueous solution_ The oxidizing and dissolving process of oxidizing and dissolving the above-mentioned oxidizing price. 2. The method described in item _'1 of the scope of patent application, wherein the P Η of the above-mentioned ozone aqueous solution is below 6. 3. If the scope of patent application is The method according to item 1, wherein in the oxidizing and dissolving process, the ozone aqueous solution is supplied to the object at 50 ° C to 80 ° C. 4. The method according to item 1 in the scope of patent application, wherein The above-mentioned ozone gas is: with a solid electrolyte as a boundary, an anode chamber on one side thereof | a cathode chamber on the other side thereof, formed by the catalyst metal in the anode chamber The anode is used to electrolyze pure water, and the ozone gas obtained by the solid electrolyte electrolysis method that generates ozone from the anode chamber. '5. The method described in item 1 of the scope of the patent application, which further includes: measuring the above-mentioned oxidation of the ozone solution. Project for reducing the potential and monitoring the oxidative dissolution performance of the above-mentioned ozone aqueous solution. 6 'The method described in item 1 of the scope of patent application, which further includes supplying a decontamination solution formed by an organic acid aqueous solution to the above-mentioned object, and reducing and dissolving the above-mentioned oxide film. Reduction and dissolution engineering 7. The method described in item 6 of the scope of patent application, which further includes: after the above reduction and dissolution engineering, decomposes and remains in the above-mentioned organic acid aqueous solution. The paper size is applicable to the Chinese Solid Standard (CNS) A4 specification (210 x 297 公 犮) .- 37- 445459 VI. Decomposition of reducing agents for organic acids within the scope of the patent application: 阅读 Read the back-to-the-next-notes and then f 矣,. This page and remove the presence of ozone water Removal of ions or ions existing in the above-mentioned organic acid aqueous solution. 8. If applying for a patent The method described in item 7 of the scope, wherein the above-mentioned reducing agent decomposition process includes: · a process of adding ozone or hydrogen peroxide to the above-mentioned organic acid aqueous solution · and a process of irradiating ultraviolet rays or radiation to the above-mentioned organic acid aqueous solution 9. The method described in item 7 of the scope of the patent application, wherein the above = Liaoyuan agent decomposition project includes: irradiating titanium oxide with light, and contacting the titanium oxide with the organic acid aqueous solution 1 through the photocatalyst of titanium oxide to decompose the organic acid. 10. Perform the method described in item 7 of the scope of patent application, which further includes: after the above-mentioned oxidizing and dissolving process, irradiating ultraviolet rays or radiation on the above-mentioned ozone water-soluble solution to decompose the oxidant oxidizing agent containing ozone contained in the aqueous ozone solution . &quot; Printed by the Consumers' Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs 1 I The method described in item 6 of the scope of patent application, wherein the organic acid aqueous solution used for the above-mentioned reduction and dissolution engineering may contain organic salts in addition to organic acids. 1 2 .—A decontamination device, which is a decontamination device for removing an oxide film containing a radioactive substance of a decontamination object attached to a constituent element of a radiation processing facility, and is characterized by having: -38- This paper size is applicable China National Standard (CNS) A4 specification (210 X 297 s &gt; Is 445 45 9 6. The scope of the patent application has a decontamination liquid circulation system for the first pump that circulates decontamination liquid through the above decontamination objects; and An ozone injection system for supplying ozone to the decontamination liquid in the above-mentioned decontamination liquid circulation system: '· and a pH adjuster supply device for supplying a pH adjuster to the above-mentioned decontamination liquid circulation system;' / and the above The supply of the decontamination liquid in the decontamination liquid circulation system as a reducing agent is an organic acid supply device having an organic acid; and a light irradiation device for irradiating light to the decontamination liquid in the above decontamination liquid circulation system: and An ion exchange device for removing ions in the decontamination liquid contained in the above-mentioned decontamination liquid circulation system. 1 3. The decontamination device described in item 12 of the scope of patent application, which further includes: is connected to constitute the above-mentioned circulation. The bypass flow path I of the flow path of the ring system, and the second pump which is provided in the bypass flow path, passes the bypass flow path and the decontamination object, and circulates the decontamination liquid. 1 4. For example, the decontamination device described in item 12 of the scope of the patent application, which further includes a buffer barrel provided in the above-mentioned circulation system; the above-mentioned ozone supply device has an ozone generator and a circulation flow path connected to the above-mentioned buffer barrel, and A mixing pump that mixes the decontamination liquid in the circulation flow path with the ozone generated by the ozone generator; the p Η regulator supply device and the organic acid supply device are configured to be able to supply the ρ Η regulator and the above Organic acids give the above relief-^ --- ^ --- ί --- 1 * i -----! I order &quot; f &quot;: ------- line (please read t side first tNote ^? Matters are reprinted by Jri-. This page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs ¾ This paper has been used in China National Standard (CNS) A4 (210 X 297 mm) -39-: ^ 445 AeB8c8D8 6. Applying for the scope of patent application for flushing buckets. 15. For the decontamination device described in item 14 of the scope of applying for patents, of which The above-mentioned decontamination object is a component that can be removed and installed by the above-mentioned radiation processing facility, and the above-mentioned buffer bucket can be impregnated with the above-mentioned decontamination object β _ 1 6 An ozone exhaust system having an ozone treatment device connected to the above buffer tank "17. The decontamination device as described in item 16 of the scope of patent application, wherein the above ozone treatment device has activated carbon that decomposes ozone into oxygen or Metal catalyst. 1 8 The decontamination device as described in item 17 of the scope of the patent application, wherein the ozone generator is formed by: using a solid electrolyte as a boundary, having an anode chamber on one side | a cathode chamber on the other side, by The anode formed by the catalytic metal in the above anode chamber ___ is used to electrically decompose pure water, and the solid electrolyte electrolysis method for ozone generation from the above anode chamber to generate ozone is used for the electrical decomposition. Device I Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs and Consumer Cooperatives The above-mentioned decontamination device further includes a combined catalyst device connected to the above-mentioned ozone treatment device and a cathode chamber of the ozone generator: The combined catalyst device is an oxygen decomposition product of ozone generated by the ozone decomposition device. And the hydrogen produced by the above-mentioned cathode chamber to produce water. 19. The decontamination device described in item 14 of the scope of the patent application, which further includes: connecting the buffer bucket to the ozone supply device, and returning ozone gas desorbed from the ozone solution in the buffer bucket to the ozone supply standard of the paper. Applicable to Zhongli Gujia standard (CNS &gt; A4 specification (210 X 297 gong)) 445459 Duty printing of employee cooperation of Intellectual Property Bureau of the Ministry of Economic Affairs _ 6. Gas flow path of patent-applied devices. 2 0. — Removal including attachment A method for oxidizing a film of a radioactive substance for a decontamination object, characterized in that the decontamination object has a coolant circulation pump connected to a coolant circulating in the atomic furnace, and an inlet of the coolant circulation pump. The side and the discharge port side include pumps whose height is higher than that of the coolant circulation pump. The method includes the following steps: setting up the first and second pipes, the ozone generator, and the organic acid supply device. . Means for manufacturing decontamination liquid, and decontamination system of decontamination liquid circulation pump connected to the first and second pipes, and the first and second pipes. Into the pipe, and then through the pipe and the inside of the coolant circulation pump, while supplying to the pipe, the decontamination liquid is discharged through the second pipe, so that the inside of the coolant circulation pump is the same as above Fill the decontamination liquid with the ground to maintain the height of the above decontamination liquid in the above tube. -41-This paper size applies the Chinese National Standard (CNS) A4 grid (210 χ 297mm: g)