JP2015158486A5

JP2015158486A5 -

Info

Publication number: JP2015158486A5
Application number: JP2015012488A
Authority: JP
Filing date: 2015-01-26
Publication date: 2017-10-12
Anticipated expiration: 2035-01-26

Description

上記した課題を解決する本発明の特徴は、還元除染剤の水溶液を用いて、原子力プラントの構造部材の炉水に接触する表面の還元除染を実施するステップ、及び還元除染後に実施される還元除染剤の分解工程内で、還元除染剤の一部を分解した後でその水溶液に還元除染剤が残っている第１期間、及びその分解工程が終了した後に実施されるその水溶液の浄化を行う第２期間の少なくとも一つの期間において、錯イオン形成剤、貴金属イオン及び還元剤をその水溶液に注入することにより生成された、錯イオン形成剤、貴金属イオン及び還元剤を含むその水溶液を、構造部材の還元除染が実施されたその表面に接触させ、その表面にその貴金属イオンから生成される貴金属を付着させるステップを有し、
還元除染を実施するステップ及び貴金属を付着させるステップが、原子力プラントの運転停止後で原子力プラントの起動前に行われることにある。 The feature of the present invention that solves the above-described problems is implemented by a step of performing reductive decontamination of the surface of the nuclear plant structural member that contacts the reactor water using an aqueous solution of a reductive decontamination agent, and after reductive decontamination. that in the decomposition step of reducing decontamination agent, the first period is left reducing decontaminating agent to the aqueous solution after decomposition of the part of the reducing decontamination agent, and its decomposition process is performed after the completion in at least one period of the second period for purifying aqueous solutions, complex ion-forming agent, were generated by injecting a noble metal ion及 beauty reducing agent in the aqueous solution, complex ion-forming agent, a precious metal ions and a reducing agent The aqueous solution containing the step of contacting the surface of the structural member on which the decontamination of the structural member has been performed, and attaching the noble metal generated from the noble metal ion to the surface;
The step of carrying out the reductive decontamination and the step of depositing the precious metal is to be performed after the nuclear plant is shut down and before the nuclear plant is started.

還元除染後に実施される還元除染剤の分解工程内で、還元除染剤の一部を分解した後でその水溶液に還元除染剤が残っている第１期間、及び還元除染剤分解工程が終了した後に実施されるその水溶液の浄化を行う第２期間の少なくとも一つの期間において、錯イオン形成剤、貴金属イオン及び還元剤をその水溶液に注入することにより生成された、錯イオン形成剤、貴金属イオン及び還元剤を含むその水溶液を、構造部材の還元除染が実施されたその表面に接触させ、その表面に貴金属を付着させるステップを有するので、原子力プラントの構造部材の表面の化学除染及びその表面への貴金属の付着に要する時間をさらに短縮することができる。還元剤の使用は、構造部材の表面への貴金属の付着効率を増大させるため、その施工時間のさらなる短縮に貢献する。 In the decontamination step of the reductive decontamination performed after reductive decontamination, the first period in which the decontamination agent remains in the aqueous solution after decomposing a part of the reductive decontamination agent, and the decontamination of the reductive decontaminant in at least one period of the second period in which process for purifying an aqueous solution thereof is performed after the completion, which is generated by implanting complex ion forming agent, a noble metal ion及 beauty reducing agent in the aqueous solution, complex ions The aqueous solution containing the forming agent, the noble metal ion and the reducing agent is brought into contact with the surface of the structural member on which the decontamination of the structural member has been performed, and the surface is attached to the surface of the structural member. The time required for chemical decontamination and adhesion of the noble metal to the surface can be further shortened. The use of the reducing agent increases the efficiency of attaching the noble metal to the surface of the structural member, which contributes to further shortening the construction time.

特に、第１期間及び第２期間の少なくとも一つの期間において、錯イオン形成剤をその水溶液に注入するため、化学除染により配管系の内面に存在する酸化被膜の溶解によって生じたＦｅ（III）イオンが注入された錯イオン形成剤と反応し、Ｆｅ（III）イオンと錯イオン形成剤との錯イオンが生成される。この結果、配管系の内面に貴金属を付着させるために、貴金属イオン及び還元剤が錯イオン形成剤を含む還元除染剤の水溶液に注入されたとき、この水溶液のｐＨが注入された還元剤の作用により上昇したとしても、還元除染剤の水溶液内のＦｅ（III）イオンが水酸化鉄及びマグネタイトになって析出することを著しく抑制することができる。この結果、還元除染剤の水溶液に含まれている貴金属イオンが配管系の内面に吸着されて還元剤の作用によって貴金属として配管系の内面に付着する量が著しく増大する。 In particular, in at least one of the first period and the second period, the complex ion forming agent is injected into the aqueous solution, so that Fe (III) generated by dissolution of the oxide film existing on the inner surface of the piping system by chemical decontamination. It reacts with the complex ion forming agent into which ions are implanted, and complex ions of Fe (III) ions and the complex ion forming agent are generated. As a result, in order to deposit the noble metal on the inner surface of the pipeline, when the noble metal ion及 beauty reducing agent is injected into an aqueous solution of a reducing decontaminating agent containing complex ion-forming agent, reducing the pH of the aqueous solution is injected Even if it is raised by the action of the agent, it is possible to remarkably suppress the precipitation of Fe (III) ions in the aqueous solution of the reductive decontamination agent as iron hydroxide and magnetite. As a result, the amount of the noble metal ions contained in the aqueous solution of the reductive decontamination agent is adsorbed on the inner surface of the piping system and adheres to the inner surface of the piping system as a noble metal due to the action of the reducing agent.

Claims

In the step of carrying out reductive decontamination of the surface of the nuclear plant structural member in contact with the reactor water using an aqueous solution of the reductive decontaminant, and in the decomposition process of the reductive decontaminant carried out after the reductive decontamination , first to purify the aqueous solution in which the reducing decontaminating agent the first period reducing decontaminating agent remains in the aqueous solution after partially disassembled, and before Symbol decomposition process is performed after the completion in at least one period of the second period, complex ion-forming agent, were generated by injecting a noble metal ion及 beauty reducing agent to the aqueous solution, the complex ion-forming agent, including the noble metal ions and the reducing agent the Bringing the aqueous solution into contact with the surface of the structural member on which the decontamination has been performed, and attaching the noble metal generated from the noble metal ions to the surface;
The method for depositing a noble metal on a structural member of a nuclear power plant, wherein the step of carrying out the reduction decontamination and the step of depositing the noble metal are performed after the nuclear power plant is stopped and before the nuclear power plant is started.

In the step of attaching the noble metal to the surface of the structural member, the aqueous solution containing the complex ion forming agent, the noble metal ion and the reducing agent injected in the first period and further containing the reducing decontamination agent is attached to the surface of the structural member. After the contact, the noble metal adheres to the surface, the reductive decontamination agent and the reducing agent contained in the aqueous solution are decomposed, and the complex ion forming agent contained in the aqueous solution is ion-exchanged in the second period. The method for attaching a noble metal to a structural member of a nuclear power plant according to claim 1, wherein the noble metal is removed by resin.

The nuclear power according to claim 2, wherein the aqueous solution containing the noble metal ions, the reducing agent, and the reducing decontamination agent brought into contact with the surface of the structural member has a pH within a range of 4.0 to 9.0. A method for attaching precious metals to structural members of a plant.

The method for attaching a noble metal to a structural member of a nuclear power plant according to claim 2, wherein the reduction decontamination agent and the reduction agent are decomposed using a catalyst and an oxidizing agent.

The aqueous solution containing the noble metal ions implanted in the first period is brought into contact with the surface of the structural member in the step of attaching the noble metal, and after the noble metal adheres to the surface, the aqueous solution The method for adhering a noble metal to a structural member of a nuclear power plant according to claim 1, wherein purification is performed by supplying the resin tower filled with an ion exchange resin and an anion exchange resin.

Injection into the aqueous solution of the noble metal ion, a noble metal deposition method of the complex ion-forming agent to structural members of a nuclear power plant according to claim 1 carried out after injection into the aqueous solution.

The method for attaching a noble metal to a structural member of a nuclear power plant according to claim 1, wherein the complex ion forming agent is at least one of ammonia, hydroxylamine, cyanide, urea, and thiocyanate.

The complex ion-forming agent, when the injection of the noble metal ion及 beauty the reducing agent is stopped in the second period, the complex ion forming agent, the removal of the noble metal ion及 beauty the reducing agent is supplied to the aqueous solution The method for attaching a noble metal to a structural member of a nuclear power plant according to claim 1, wherein the method is carried out in a resin tower filled with an ion exchange resin.

2. The nuclear power plant according to claim 1, wherein the complex ion forming agent is injected into the aqueous solution when the measured concentration of iron (III) ions in the aqueous solution is equal to or lower than a set concentration of iron (III) ions. Method for attaching noble metals to structural members of

An aqueous solution of a reducing decontamination agent is supplied to a first pipe, which is a structural member of a nuclear power plant, communicated with the nuclear pressure vessel through the second pipe, and the inner surface of the first pipe is reduced using this aqueous solution. And a part of the reductive decontaminant in the decomposition process of the reductive decontaminant contained in the aqueous solution discharged from the first pipe, which is performed after the reductive decontamination second performing the first period remains the reducing decontaminating agent to the aqueous solution after decomposition, and pre-Symbol decomposition process is performed after the completion of the purification of the aqueous solution discharged from the first pipe in at least one period of the period, complex ion-forming agent, a noble metal ion及 beauty reducing agent was generated by injecting the aqueous solution, the complex ion forming agent, the aqueous solution containing the precious metal ions and the reducing agent The above 2 is supplied to the first pipe into contact with the inner surface of the first pipe through the pipe, comprising the step of depositing a noble metal generated from the noble metal ions to the inner surface,
The method for depositing a noble metal on a structural member of a nuclear power plant, wherein the step of carrying out the reduction decontamination and the step of depositing the noble metal are performed after the nuclear power plant is stopped and before the nuclear power plant is started.

An aqueous solution of a reducing decontamination agent is supplied to a first pipe, which is a structural member of a nuclear power plant, communicated with the nuclear pressure vessel through the second pipe, and the inner surface of the first pipe is reduced using this aqueous solution. A step of decomposing a part of the reductive decontaminating agent contained in the aqueous solution discharged from the first pipe, which is performed after completion of the reductive decontamination to increase the pH of the aqueous solution. step, complex ion-forming agent, noble metal ions the pH down及 beauty reducing agent was generated by injecting the aqueous solution containing the reducing decontamination agent increases, the complex ion forming agent, the noble metal ions, said reducing agent and the aqueous solution containing the reducing decontamination agent is supplied to the first pipe through the second pipe into contact with the inner surface of the first pipe, depositing a noble metal generated from the noble metal ions to the inner surface Step, and after the step of depositing the noble metal is finished, comprising the step of decomposing the reducing decontamination agent and the reducing agent contained in the aqueous solution discharged from the first pipe,
Step of increasing the pH of the aqueous solution, the steps and the step of decomposing the reducing decontamination agent and the reducing agent to deposit the noble metal, from the start of the decomposition step of the reducing decontaminant carried out after the reduction decontamination is carried out within a period of until the end of the previous Symbol decomposition process,
The steps and before Symbol decomposition process to implement the reduction decontamination, precious metal deposition method of the structural members of a nuclear power plant, characterized in that takes place before activation of the nuclear power plant after shutdown of the nuclear plant.

The pH of the aqueous solution containing the noble metal ions, the reducing agent, and the reducing decontamination agent supplied to the first piping through the second piping is in the range of 4.0 to 9.0. A method for attaching a noble metal to a structural member of a nuclear power plant as described in 1.

The structural member of the nuclear power plant according to claim 11, wherein the reduction decontamination agent and the reduction agent are decomposed in the step of decomposing the reduction decontamination agent and the reduction agent using a catalyst and an oxidizing agent. Noble metal adhesion method.

The reducing decontamination agent in the step of decomposing the reducing decontamination agent and the reducing agent when the aqueous solution containing the noble metal ion, the reducing agent and the reducing decontamination agent is supplied to the first pipe; The method for attaching a noble metal to a structural member of a nuclear power plant according to claim 11, wherein the reducing agent is decomposed.

The decomposition of the reducing decontamination agent, noble metal deposition method of the structural members of a nuclear power plant of claim 14 which is carried out using a catalyst Nakadachi及beauty oxidation agent is performed in step of increasing the pH of the aqueous solution.

The first measures the adhesion amount of the noble metal to the inner surface of the pipe to stop the injection into the aqueous solution of the noble metal ion及 beauty said reducing agent based on the amount of deposition of the noble metal measured claims 10 or 11. A method for attaching a noble metal to a structural member of a nuclear power plant according to 11.

The method for attaching a noble metal to a structural member of a nuclear power plant according to any one of claims 1, 10, and 11, wherein the reductive decontamination is performed using the aqueous solution containing the reductive decontaminant and a pH adjuster.

The structural member of the nuclear power plant according to any one of claims 1, 10, and 11, wherein the reductive decontamination is performed using the aqueous solution containing the reductive decontaminant and not containing a pH adjuster. Precious metal adhesion method.

Complex comprising the complex ion-forming agent, and the noble metal ions to be generated by mixing the complex ion forming agent及 beauty the noble metal ions prior to injection into the aqueous solution, the complex ion forming agent and the noble metal ion ion, the complex ion forming agent, the noble metal ions及 beauty the aqueous solution the containing together with a reducing agent, noble metal deposition method of the structural members of a nuclear power plant according to claim 1 into contact with said surface.

The mixture of complex ion formation agent及 beauty the noble metal ions is carried out in a mixing vessel, wherein the aqueous solution is brought into contact with said surface, said complex ions generated in the mixing chamber, the complex ion forming agent, the noble metal deposition method of the structural members of a nuclear power plant of claim 19 which contains together with a noble metal ion及 beauty the reducing agent.

The mixture of complex ion formation agent及 beauty the noble metal ions is carried out in advance, the unrealized and including mixed-solution of the complex ion forming agent及 beauty the noble metal ions the complex ions generated by this mixing tank The method for adhering a noble metal to a structural member of a nuclear power plant according to claim 19, wherein the mixed aqueous solution is injected into the aqueous solution of the reducing decontaminating agent.

In the step of carrying out reductive decontamination of the surface of the nuclear plant structural member in contact with the reactor water using an aqueous solution of the reductive decontaminant, and in the decomposition process of the reductive decontaminant carried out after the reductive decontamination , first to purify the aqueous solution in which the reducing decontaminating agent the first period reducing decontaminating agent remains in the aqueous solution after partially disassembled, and before Symbol decomposition process is performed after the completion in at least one period of the second period, complex ion-forming agent, and a noble metal ion is generated by injecting the aqueous solution, the complex ion-forming agent, and the aqueous solution containing the noble metal ion, wherein the structural member Contacting the surface on which the reductive decontamination has been performed, and adsorbing the noble metal ions on the surface,
The aqueous solution containing the reducing agent produced by injecting the reducing agent into the aqueous solution is brought into contact with the surface on which the noble metal ions are adsorbed, so that the noble metal ions adsorbed on the surface are converted into the reducing agent. And a second step of converting the noble metal ions adsorbed on the surface into noble metals,
The method for attaching a noble metal to a structural member of a nuclear power plant, wherein the first and second steps are performed after the nuclear power plant is stopped and before the nuclear power plant is started.

Complex comprising the complex ion forming agent及 beauty said generated by mixing a noble metal ion, the complex ion forming agent and the noble metal ions prior to injecting the complex ion forming agent及 beauty the noble metal ions to the aqueous solution ions, said aqueous solution containing both said complex ion forming agent及 beauty the noble metal ion, a noble metal deposition method of the structural members of a nuclear power plant according to claim 22 into contact with the surface.