JP2011069670A - Reduction conditioning method and treater for neptunium by using electrolytic reduction method - Google Patents

Reduction conditioning method and treater for neptunium by using electrolytic reduction method Download PDF

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JP2011069670A
JP2011069670A JP2009219649A JP2009219649A JP2011069670A JP 2011069670 A JP2011069670 A JP 2011069670A JP 2009219649 A JP2009219649 A JP 2009219649A JP 2009219649 A JP2009219649 A JP 2009219649A JP 2011069670 A JP2011069670 A JP 2011069670A
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neptunium
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Akihiro Kitatsuji
章浩 北辻
Takami Kimura
貴海 木村
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a reduction conditioning method and a treater for neptunium by using an electrolytic reduction method which require no addition of new chemicals and can also adapt to a solution with a high concentration of nitric acid efficiently in a short time. <P>SOLUTION: Platinum with platinum black is used for a cathode to reduce neptunium ions in a water solution to quadrivalent ones by the electrolytic reduction method. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、電解還元法によるネプツニウムの還元調整法および処理装置に関するものである。   The present invention relates to a method for adjusting reduction of neptunium by an electrolytic reduction method and a processing apparatus.

高レベル放射性廃液中から長半減期のネプツニウムを分離することは高レベル放射性廃液の処理処分の軽減化に有効である。ネプツニウムは、高レベル放射性廃液のような酸性溶液中で３価から６価の原子価をとる。このうち５価のイオンは最も安定であるが、抽出剤や吸着剤との親和力が小さいため、溶媒抽出法やイオン交換法などによる選択的な分離・回収が困難であることが知られている。そこで、４価に還元調整する、あるいは６価に酸化調整することにより、より親和力の大きい原子価イオンとして分離することが提案されている。例えば、特許文献１等には、４価に還元調整した後に分離する方法が開示されている。   Separating long half-life neptunium from high-level radioactive liquid waste is effective in reducing the disposal of high-level radioactive liquid waste. Neptunium has a valence of 3 to 6 in an acidic solution such as a high level radioactive liquid waste. Among these, pentavalent ions are the most stable, but are known to be difficult to selectively separate and recover by a solvent extraction method, an ion exchange method or the like because of their low affinity with an extractant or adsorbent. . Therefore, it has been proposed to separate the valence ions with higher affinity by adjusting the reduction to tetravalent or by adjusting the oxidation to hexavalent. For example, Patent Document 1 and the like disclose a method of separation after adjusting to tetravalent reduction.

ネプツニウム５価／４価の酸化還元電位は、標準水素電極に対しておよそ+0.7Vであるが、実際のネプツニウム５価から４価への還元は過電圧が大きく、より大きなエネルギーを必要とする。ネプツニウム５価から４価への還元は、これまでに還元剤を用いる化学法、および電解法が検討されてきた。   The neptunium pentavalent / tetravalent oxidation-reduction potential is about +0.7 V with respect to the standard hydrogen electrode. However, the actual reduction of neptunium pentavalent to tetravalent has a large overvoltage and requires larger energy. For the reduction from neptunium pentavalent to tetravalent, chemical methods using a reducing agent and electrolytic methods have been studied so far.

例えば、特許文献１には、アスコルビン酸を還元剤に用いたネプツニウムの還元法と溶媒抽出による分離法が開示されている。特許文献２には、ヒドラジンあるいはヒドロキシルアミンを還元剤として用いた、白金族触媒下でのネプツニウムの還元法が開示されている。特許文献３には、ヒドロキシルアミンまたはヒドラジンによる、鉄イオン共存下でのネプツニウムの還元反応が開示されている。また、特許文献４には、白金などの触媒下でのネプツニウムなどのイオンの原子価調整における、助触媒による反応速度の増加が開示されている。しかしながら、これらの方法では還元剤あるいは助触媒として用いる鉄イオンなどが新たな廃棄物として発生する問題点がある。   For example, Patent Document 1 discloses a neptunium reduction method using ascorbic acid as a reducing agent and a separation method by solvent extraction. Patent Document 2 discloses a method for reducing neptunium under a platinum group catalyst using hydrazine or hydroxylamine as a reducing agent. Patent Document 3 discloses a reduction reaction of neptunium in the presence of iron ions with hydroxylamine or hydrazine. Patent Document 4 discloses an increase in reaction rate due to a promoter in adjusting the valence of ions such as neptunium under a catalyst such as platinum. However, these methods have a problem that iron ions used as a reducing agent or a co-catalyst are generated as new waste.

特許文献５や非特許文献１には、電解法によってネプツニウムを還元することが開示されている。しかしながら、特許文献５には具体的な電解条件が開示されていない。非特許文献１には白金電極による電解還元法が開示されているが、この方法は、電極に印加する過電圧が非常に大きく、水素ガス発生などの副反応が生じるため電流効率が悪い。また、還元されたネプツニウムは、３価および４価の混合物となるため、ネプツニウム４価へ調整するための再酸化が必要である。   Patent Document 5 and Non-Patent Document 1 disclose that neptunium is reduced by an electrolytic method. However, Patent Document 5 does not disclose specific electrolysis conditions. Non-Patent Document 1 discloses an electrolytic reduction method using a platinum electrode, but this method has a very large overvoltage applied to the electrode, and a side reaction such as generation of hydrogen gas occurs, resulting in poor current efficiency. Moreover, since the reduced neptunium becomes a mixture of trivalent and tetravalent, reoxidation is necessary to adjust to neptunium tetravalent.

特開２００７−１３９４９６号公報JP 2007-139496 A 特開平３−１４０８９７号公報Japanese Patent Laid-Open No. 3-140897 特開平６−１９４４９６号公報JP-A-6-19496 特開平６−３４９４号公報JP-A-6-3494 特開平７−５５９９２号公報JP-A-7-55992

Y. Li, Y. Kato, Z. Yoshida, Electrolytic preparation of neptunium species in concentrated carbonate media,Radiochimica Acta 60 115-119(1993).Y. Li, Y. Kato, Z. Yoshida, Electrolytic preparation of neptunium species in concentrated carbonate media, Radiochimica Acta 60 115-119 (1993).

本発明は、以上の通りの事情に鑑みてなされたものであり、新たな化学薬品の添加を必要とせず、短時間で効率的に、かつ高い硝酸濃度の溶液へ適応できる、電解還元法によるネプツニウムの還元調整法および処理装置を提供することを課題としている。   The present invention has been made in view of the circumstances as described above, and does not require the addition of a new chemical, can be applied to a solution having a high nitric acid concentration efficiently in a short time, and is based on an electrolytic reduction method. It is an object of the present invention to provide a method for adjusting reduction of neptunium and a processing apparatus.

本発明は以下のことを特徴としている。   The present invention is characterized by the following.

第１には、電解還元法により水溶液中のネプツニウムイオンを４価に還元調整する方法であって、白金黒付き白金を陰極に使用する。   The first is a method of adjusting the neptunium ions in an aqueous solution to tetravalent by electrolytic reduction, and platinum with platinum black is used as a cathode.

第２には、上記第１の発明において、電解還元の陰極電位が、標準水素電極電位に対して+225mV〜+300mVの範囲である。   Second, in the first invention, the cathode potential for electrolytic reduction is in the range of +225 mV to +300 mV with respect to the standard hydrogen electrode potential.

第３には、上記第１または第２の発明において、ネプツニウムイオンを含む水溶液が、硝酸溶液である。   Third, in the first or second invention, the aqueous solution containing neptunium ions is a nitric acid solution.

第４には、上記第１または第３の発明のいずれかの電解還元法によるネプツニウムの還元調整法を行う処理装置であって、陰極と、陽極と、ネプツニウムイオンを含む水溶液を収容する電解槽と、前記陰極および前記陽極に電流を通電して水溶液中のネプツニウムイオンを還元する直流電源とを備え、前記陰極は、白金黒付き白金で構成される。   Fourth, there is provided a processing apparatus for performing a reduction adjustment method of neptunium by the electrolytic reduction method according to any one of the first and third inventions, wherein the electrolytic cell contains a cathode, an anode, and an aqueous solution containing neptunium ions. And a direct current power source for reducing neptunium ions in the aqueous solution by passing a current through the cathode and the anode, and the cathode is made of platinum with platinum black.

本発明によれば、白金黒付き白金を陰極に使用することにより、還元剤や触媒などの化学薬品を添加することなく、短時間でネプツニウムイオンを４価に還元調整できる。しかも、高い硝酸濃度の溶液へ適応できる。したがって、高レベル放射性廃液中のネプツニウムイオンを４価に還元調整した後、溶媒抽出法などにより高レベル放射性廃液からネプツニウムを選択的に容易に分離、回収することができる。   According to the present invention, by using platinum with platinum as a cathode, neptunium ions can be reduced and adjusted to tetravalent in a short time without adding chemicals such as a reducing agent and a catalyst. Moreover, it can be applied to a solution having a high nitric acid concentration. Therefore, after neptunium ions in the high-level radioactive liquid waste are reduced and adjusted to tetravalent, neptunium can be selectively and easily separated and recovered from the high-level radioactive liquid waste by a solvent extraction method or the like.

さらに本発明によれば、電解に要する印加電圧を低くすることが可能であり、電解に要する電力量を低減できる利点も有する。また、参照極と陰極間の電位差を、標準水素電極電位に対して+300mVよりも負電位、かつ一定の電位差になるように調整することにより、より効果的に短時間でネプツニウム４価に還元調整できる。そして、参照極と陰極間の電位差を、標準水素電極電位に対し+225mVよりも正電位にすることにより、３価を含まないネプツニウム４価イオンに調整でき、また、水素ガスの発生や硝酸イオンの分解などの副反応を低減することができる。   Furthermore, according to the present invention, the applied voltage required for electrolysis can be lowered, and there is an advantage that the amount of power required for electrolysis can be reduced. In addition, by adjusting the potential difference between the reference electrode and the cathode so that the potential difference is more negative than the standard hydrogen electrode potential by + 300mV and a constant potential difference, the neptunium tetravalent is reduced more effectively in a short time. Can be adjusted. The potential difference between the reference electrode and the cathode can be adjusted to a neptunium tetravalent ion that does not include trivalent ions by making the potential difference more positive than +225 mV with respect to the standard hydrogen electrode potential. Side reactions such as decomposition of can be reduced.

本発明にかかる電解還元法によるネプツニウムの還元調整法に用いられる処理装置の一実施形態である電解セルの模式図である。It is a schematic diagram of the electrolytic cell which is one Embodiment of the processing apparatus used for the reduction | restoration adjustment method of the neptunium by the electrolytic reduction method concerning this invention. 実施例において3 mol dm-3硝酸中のネプツニウム5価イオンを電解還元した際のネプツニウム5価イオン濃度の経時変化である。In the examples, the neptunium pentavalent ion concentration changes with time when the neptunium pentavalent ion in 3 mol dm -3 nitric acid is electrolytically reduced.

本発明にかかる電解還元法によるネプツニウムの還元調整法および処理装置の実施形態について、図１を参照して説明する。   An embodiment of a method for adjusting reduction of neptunium by an electrolytic reduction method and a processing apparatus according to the present invention will be described with reference to FIG.

図１は、本発明にかかる電解還元法によるネプツニウムの還元調整法に用いられる処理装置の一実施形態である電解セルの模式図である。   FIG. 1 is a schematic view of an electrolytic cell which is an embodiment of a treatment apparatus used in a method for adjusting the reduction of neptunium by the electrolytic reduction method according to the present invention.

この電解セル１は、高レベル放射性廃液等のネプツニウムイオンを含む水溶液を収納する電解槽２と硝酸溶液等の電解液を収納する陽極槽３とが密閉構造に形成されており、各槽は隔膜を隔てて連通されている。電解槽２には、陰極４が挿入されている。この陰極４は、白金黒付き白金から構成されており、例えば、電解槽２に塩化白金酸水溶液を満たし、陰極電流密度を1.0mAcm-2〜0.1Acm-2の範囲に電流制御した電解条件で定電流電解を行うことにより、塩化白金酸水溶液を電解し、白金網や白金板に白金黒を電解析出させて作製される。図１では、白金網に白金黒を電解析出させて作製したものを陰極４として使用している。また、電解槽２には、陰極電位を測定する参照極５が設置されている。この参照極５は、例えば、Ag-AgCl等から構成されている。さらに電解槽２には、攪拌子７が設置されており、電解槽２に満たされた高レベル放射性廃液等のネプツニウムイオンを含む水溶液を攪拌できるようになっている。 In this electrolytic cell 1, an electrolytic cell 2 that stores an aqueous solution containing neptunium ions such as high-level radioactive waste liquid and an anode cell 3 that stores an electrolytic solution such as a nitric acid solution are formed in a sealed structure. Communicated with each other. A cathode 4 is inserted into the electrolytic cell 2. The cathode 4 is made of platinum with platinum black. For example, the electrolytic cell 2 is filled with a chloroplatinic acid aqueous solution and the cathode current density is controlled in the range of 1.0 mAcm −2 to 0.1 Acm −2 in an electrolytic condition. By performing constant current electrolysis, an aqueous chloroplatinic acid solution is electrolyzed, and platinum black is electrolytically deposited on a platinum net or a platinum plate. In FIG. 1, a cathode 4 produced by electrolytically depositing platinum black on a platinum net is used. Further, a reference electrode 5 for measuring the cathode potential is installed in the electrolytic cell 2. The reference electrode 5 is made of, for example, Ag—AgCl. Further, a stirring bar 7 is installed in the electrolytic cell 2 so that an aqueous solution containing neptunium ions such as high-level radioactive waste liquid filled in the electrolytic cell 2 can be stirred.

陽極槽３には、例えば、白金、チタン、高密度黒鉛等から構成される陽極６が挿入されている。この陽極６と前記陰極４は直流電源に接続されている。   For example, an anode 6 made of platinum, titanium, high-density graphite or the like is inserted into the anode tank 3. The anode 6 and the cathode 4 are connected to a DC power source.

以上の構成の電解セルにおいて、電解槽にネプツニウム５価イオンを含む水溶液、例えば、高濃度の硝酸溶液である高レベル放射性廃液を満たし、陽極槽に硝酸溶液等の電解液を満たし、直流電源により陰極と陽極間に電位差を印加して電解することにより、ネプツニウム５価イオンを４価に還元する。   In the electrolytic cell having the above-described configuration, the electrolytic cell is filled with an aqueous solution containing neptunium pentavalent ions, for example, a high-level radioactive waste solution that is a high-concentration nitric acid solution, the anode cell is filled with an electrolytic solution such as a nitric acid solution, By applying a potential difference between the cathode and the anode and electrolyzing, the neptunium pentavalent ions are reduced to tetravalent.

このとき、参照極と陰極間の電位差を、標準水素電極電位に対して+300mVよりも負電位、一定の電位差になるように調整することが望ましい。水溶液中のネプツニウム５価イオンのほとんどを最大でも30分程度でネプツニウム４価イオンに還元調整できるからである。なお、後述する実施例のように、参照極と陰極間の電位差を、標準水素電極電位に対して+245mVの一定値に保ちながら電解することにより、15分程度で水溶液中のネプツニウム５価イオンのほとんどをネプツニウム４価イオンに還元調整できる。参照極と陰極間の電位差を、+245mVよりも負電位側に変化させた場合、電解に要する時間は+245mVの場合とほぼ同じであるが、ネプツニウムの電解還元に伴い、硝酸イオンの分解や水素ガスの発生等の副反応が生じ余分な電流が消費されるため、電流効率（ネプツニウムの還元に要する電流／全電流）が低下する。陰極電位+225mV程度までは、その電流効率の低下度合いが小さいか又はほぼ一定であり、10％以上の電流効率を示すが、陰極電位を+225mVよりも負電位側に変化させたときは、電流効率の低下度合いが顕著であり、電流効率が10％未満となる。したがって、本実施形態では、参照極と陰極間の電位差を標準水素電極電位に対して+225mV〜+300mVの範囲にして電解を行うことが好ましい。   At this time, it is desirable to adjust the potential difference between the reference electrode and the cathode so that it is a negative potential and a constant potential difference from +300 mV with respect to the standard hydrogen electrode potential. This is because most of the neptunium pentavalent ions in the aqueous solution can be reduced and adjusted to neptunium tetravalent ions in about 30 minutes at the maximum. As in the examples described later, the neptunium pentavalent ion in the aqueous solution is obtained in about 15 minutes by electrolysis while maintaining the potential difference between the reference electrode and the cathode at a constant value of +245 mV with respect to the standard hydrogen electrode potential. Most of these can be reduced and adjusted to neptunium tetravalent ions. When the potential difference between the reference electrode and the cathode is changed from +245 mV to the negative potential side, the time required for electrolysis is almost the same as that for +245 mV. Since side reactions such as generation of hydrogen gas occur and an excess current is consumed, current efficiency (current required for reduction of neptunium / total current) is reduced. Until the cathode potential is about +225 mV, the degree of decrease in the current efficiency is small or almost constant and shows a current efficiency of 10% or more, but when the cathode potential is changed to the negative potential side from +225 mV, The degree of decrease in current efficiency is significant, and the current efficiency is less than 10%. Therefore, in this embodiment, it is preferable to perform electrolysis with the potential difference between the reference electrode and the cathode in the range of +225 mV to +300 mV with respect to the standard hydrogen electrode potential.

本実施形態では、ネプツニウム５価イオンを含む水溶液に、ネプツニウム６価イオンあるいは３価イオンが含まれている場合でも、全てネプツニウム４価イオンに調整することができる。また、電解中に水溶液を攪拌子で攪拌することにより、より効率よく電解還元することができる。   In the present embodiment, even when neptunium hexavalent ions or trivalent ions are contained in an aqueous solution containing neptunium pentavalent ions, all can be adjusted to neptunium tetravalent ions. Moreover, electrolytic reduction can be performed more efficiently by stirring the aqueous solution with a stirrer during electrolysis.

以上、実施形態に基づき本発明を説明したが、本発明は上記の実施形態に何ら限定されるものではなく、その要旨を逸脱しない範囲内において各種の変更が可能である。以下、本発明の実施例を具体的に説明する。   While the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Examples of the present invention will be specifically described below.

ネプツニウム５価イオンの還元調整は図１に示した電解セル１で行った。陰極４としての白金黒付き白金は、塩化白金酸を含む塩酸溶液中で1.6mAcm-2の電流密度で5時間電解することにより、白金網（80メッシュ、60×20mm）に白金黒を電析させて作製した。陽極６はPt、参照極５はAg-AgClで構成されている。 The reduction adjustment of neptunium pentavalent ions was performed in the electrolytic cell 1 shown in FIG. Platinum black with platinum as the cathode 4 is electroplated in a hydrochloric acid solution containing chloroplatinic acid at a current density of 1.6 mAcm -2 for 5 hours to deposit platinum black on a platinum mesh (80 mesh, 60 x 20 mm). Made. The anode 6 is composed of Pt, and the reference electrode 5 is composed of Ag—AgCl.

この白金黒付き白金陰極を用いて3 mol dm-3硝酸中のネプツニウム５価イオンを電解還元した。参照極と陰極間の電位差を、標準水素電極に対して+245 mVの一定値に保ちながら電解した。図２は、硝酸溶液中のネプツニウム５価イオン濃度の経時変化である。白金黒付き白金を陰極に用いた場合（図２中の黒丸印）、図２中の黒の四角印で示した白金黒を付着させない電極（白金電極）を陰極に用いた場合に比べて、還元に要する時間が著しく減少することが確認できた。15分間の電解後の硝酸溶液中のネプツニウム４価イオンの純度は99%以上であった。 Using this platinum black-plated platinum cathode, neptunium pentavalent ions in 3 mol dm -3 nitric acid were electrolytically reduced. Electrolysis was performed while maintaining the potential difference between the reference electrode and the cathode at a constant value of +245 mV with respect to the standard hydrogen electrode. FIG. 2 shows the change over time of the neptunium pentavalent ion concentration in the nitric acid solution. When platinum with platinum black is used for the cathode (black circle in FIG. 2), compared with the case where an electrode (platinum electrode) that does not attach platinum black indicated by the black square mark in FIG. 2 is used for the cathode, It was confirmed that the time required for the reduction was remarkably reduced. The purity of the neptunium tetravalent ion in the nitric acid solution after electrolysis for 15 minutes was 99% or more.

また、白金黒付き白金を陰極に用い、参照極と陰極間の電位差を標準水素電極に対して+300 mV、+310 mVの値に各々一定値に保ちながら電解したときの、硝酸溶液中のネプツニウム５価イオン濃度の経時変化も図２に示す。図２中の黒三角印が+300 mVのときの経時変化であり、黒の逆三角印が+310 mVのときの経時変化である。この結果から、参照極と陰極間の電位差が+300mVの場合、およそ30分でネプツニウム5価イオンの99%を還元でき、その電位差よりも正電位である+310 mVの場合では、より長い電解時間を要することが確認できた。   In addition, in the nitric acid solution when platinum was used as a cathode and electrolysis was carried out while maintaining the potential difference between the reference electrode and the cathode at +300 mV and +310 mV, respectively, with respect to the standard hydrogen electrode. The time course of the neptunium pentavalent ion concentration is also shown in FIG. This is a change with time when the black triangle mark in FIG. 2 is +300 mV, and a change with time when the black inverted triangle mark is +310 mV. From this result, when the potential difference between the reference electrode and the cathode is +300 mV, 99% of the neptunium pentavalent ions can be reduced in about 30 minutes, and when the potential difference is +310 mV, which is a positive potential, longer electrolysis is required. It was confirmed that it takes time.

また、参照極と陰極間の電位差（電解電位）が標準水素電極に対して+145mV〜+345mVの範囲において、電位差を一定に保ちながら電解還元したときの電解電位と電流効率（ネプツニウムの還元に要する電流／全電流）との関係を表１に示す。   In addition, when the potential difference (electrolytic potential) between the reference electrode and the cathode is +145 mV to +345 mV with respect to the standard hydrogen electrode, the electrolytic potential and current efficiency (for reduction of neptunium) when electrolytic reduction is performed while keeping the potential difference constant. Table 1 shows the relationship between (current required / total current).

表１の結果より、電解電位が+225mVよりも負電位であると電流効率が著しく低下することがわかる。なお、電解電位が+225mVよりも負電位のときの電解に要する時間は、+225mVの場合とほぼ同じであった。   From the results in Table 1, it can be seen that when the electrolytic potential is more negative than +225 mV, the current efficiency is significantly reduced. The time required for electrolysis when the electrolysis potential was more negative than +225 mV was almost the same as that for +225 mV.

１ 電解セル
２ 電解槽
３ 陽極槽
４ 陰極
５ 参照極
６ 陽極
７ 攪拌子 DESCRIPTION OF SYMBOLS 1 Electrolysis cell 2 Electrolysis tank 3 Anode tank 4 Cathode 5 Reference electrode 6 Anode 7 Stirrer

Claims (4)

電解還元法により水溶液中のネプツニウムイオンを４価に還元調整する方法であって、白金黒付き白金を陰極に使用することを特徴とする電解還元法によるネプツニウムの還元調整法。   A method for adjusting the reduction of neptunium ions in an aqueous solution by an electrolytic reduction method, wherein platinum with platinum black is used as a cathode. 電解還元の陰極電位が、標準水素電極電位に対して+225mV〜+300mVの範囲であることを特徴とする請求項１に記載の電解還元法によるネプツニウムの還元調整法。   2. The method for adjusting the reduction of neptunium by the electrolytic reduction method according to claim 1, wherein the cathode potential of electrolytic reduction is in the range of +225 mV to +300 mV with respect to the standard hydrogen electrode potential. ネプツニウムイオンを含む水溶液が、硝酸溶液であることを特徴とする請求項１または２に記載の電解還元法によるネプツニウムの還元調整法。   The method for adjusting the reduction of neptunium by the electrolytic reduction method according to claim 1, wherein the aqueous solution containing neptunium ions is a nitric acid solution. 請求項１から３のいずれかの電解還元法によるネプツニウムの還元調整法を行う処理装置であって、陰極と、陽極と、ネプツニウムイオンを含む水溶液を収容する電解槽と、前記陰極および前記陽極に電流を通電して水溶液中のネプツニウムイオンを還元する直流電源とを備え、前記陰極は、白金黒付き白金で構成されることを特徴とする処理装置。   A processing apparatus for performing a neptunium reduction adjustment method according to any one of the electrolytic reduction methods according to claim 1, wherein a cathode, an anode, an electrolytic cell containing an aqueous solution containing neptunium ions, the cathode and the anode are provided. A processing apparatus comprising: a direct current power source for supplying a current to reduce neptunium ions in an aqueous solution; and the cathode is made of platinum with platinum black.
JP2009219649A 2009-09-24 2009-09-24 Reduction conditioning method and treater for neptunium by using electrolytic reduction method Pending JP2011069670A (en)

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JP2021079300A (en) * 2019-11-14 2021-05-27 株式会社東芝 Electrolytic extractor and electrolytic extraction method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021079300A (en) * 2019-11-14 2021-05-27 株式会社東芝 Electrolytic extractor and electrolytic extraction method
JP7362439B2 (en) 2019-11-14 2023-10-17 株式会社東芝 Electrolytic extraction equipment and electrolytic extraction method

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