JPH0815483A - Method for solvent extraction of transuranium elements - Google Patents
Method for solvent extraction of transuranium elementsInfo
- Publication number
- JPH0815483A JPH0815483A JP14280094A JP14280094A JPH0815483A JP H0815483 A JPH0815483 A JP H0815483A JP 14280094 A JP14280094 A JP 14280094A JP 14280094 A JP14280094 A JP 14280094A JP H0815483 A JPH0815483 A JP H0815483A
- Authority
- JP
- Japan
- Prior art keywords
- acid
- solvent
- waste liquid
- extraction
- organic phase
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
Landscapes
- Extraction Or Liquid Replacement (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、使用済核燃料の再処理
技術に係わり、更に詳しくは、高レベル廃液から超ウラ
ン元素を溶媒抽出する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for reprocessing spent nuclear fuel, and more particularly to a method for solvent extraction of transuranium elements from a high level waste liquid.
【０００２】[0002]
【従来の技術】原子力発電設備で発生する使用済核燃料
の再処理技術としてＰＵＲＥＸプロセス(Plutonium ura
nium recovery by extraction)が従来から用いられてい
る。このＰＵＲＥＸプロセスは、ＴＢＰ(tri-n-butyl p
hosphate) を抽出溶媒として使用し、使用済燃料溶解液
中のＵ（ウラン）、Ｐｕ（プルトニウム）を個別に高効
率かつ高純度で回収するプロセスであるが、濃縮前の廃
液を処理するため多量の放射性廃液が発生し、かつこの
放射性廃液中に超ウラン元素（ＴＲＵ元素）が残存し、
これらの半減期が非常に長い（例えば１０3 〜１０
4 年）ため、高レベル廃液貯蔵量を増す要因となってい
る。2. Description of the Related Art The PUREX process (Plutonium ura) is used as a reprocessing technology for spent nuclear fuel generated in nuclear power generation facilities.
nium recovery by extraction) has been used conventionally. This PUREX process is based on TBP (tri-n-butyl p
hosphate) is used as an extraction solvent, and U (uranium) and Pu (plutonium) in the spent fuel solution are individually recovered with high efficiency and high purity. Radioactive waste liquid is generated, and transuranium element (TRU element) remains in this radioactive waste liquid,
These half-lives are very long (eg 10 3 -10
4 years), which is a factor that increases the high-level waste liquid storage volume.
【０００３】これに対して、図７に模式的に示すよう
に、使用済燃料を再処理（濃縮）して高レベル廃液と
し、これから超ウラン元素（ＴＲＵ元素）を含む再利用
可能な元素を群分離するＴＲＵＥＸプロセス(TRU Extra
ction Process)が、米国アルゴンヌ国立研究所から提案
され、現在世界各国で鋭意研究開発されている。このＴ
ＲＵＥＸプロセスは、前記ＰＵＲＥＸプロセスの溶媒に
少量のＣＭＰＯ(octyle(phenyl)-N,N-diisobutylcarbam
oylmethyl-phosphine oxide)を添加した溶媒を用い、図
８のプロセスフロー図に示すように、高レベル廃液から
直接再利用可能な元素を「抽出／スクラブ」工程で抽出
及び洗浄し、これを例えば「逆抽出１」工程において逆
抽出液１でＡｍ（アメリシウム）、Ｃｍ（キュリウム）
等のＴＲＵ元素を回収し、「逆抽出２」工程において逆
抽出液２でＰｕ、Ｎｐ（ネプツニウム）等を回収するプ
ロセスである。逆抽出工程は３工程以上の場合もある。On the other hand, as schematically shown in FIG. 7, spent fuel is reprocessed (concentrated) into a high-level waste liquid, from which reusable elements including transuranium elements (TRU elements) are added. TRUEX process for group separation (TRU Extra
ction process) has been proposed by Argonne National Laboratory in the United States, and is currently being researched and developed all over the world. This T
The RUEX process uses a small amount of CMPO (octyle (phenyl) -N, N-diisobutylcarbam) as a solvent for the PUREX process.
Using a solvent to which oylmethyl-phosphine oxide has been added, as shown in the process flow diagram of FIG. 8, elements that can be directly reused from high-level waste liquid are extracted and washed in the “extraction / scrub” step, In the “back extraction 1” step, the back extraction liquid 1 was used for Am (americium) and Cm (curium).
Is a process of recovering Pu, Np (neptunium) and the like with the back extraction liquid 2 in the “back extraction 2” step. The back extraction step may be three or more steps.
【０００４】このＴＲＵＥＸプロセスは、廃液を濃縮し
た高レベル廃液を直接処理できることから高レベルの放
射性廃液量をさらに少なくでき、かつ半減期が非常に長
い超ウラン元素（ＴＲＵ元素）を回収するため、放射性
廃液の処理が容易となる特徴がある。The TRUEX process can directly treat a high-level waste liquid obtained by concentrating the waste liquid, so that the amount of the high-level radioactive waste liquid can be further reduced and the transuranium element (TRU element) having a very long half-life is recovered. It has the feature of facilitating the treatment of radioactive waste liquid.
【０００５】[0005]
【発明が解決しようとする課題】しかし、かかるＴＲＵ
ＥＸプロセスの溶剤に含まれるＣＭＰＯにより、抽出対
象元素であるアクチノイド（Ｕ、Ａｍ、Ｃｍ、Ｐｕ、Ｎ
ｐ等）以外に、不純物となるＺｒ（ジルコニウム）、Ｍ
ｏ（モリブデン）等も抽出されてしまう問題点があっ
た。これらの不純物の抽出を抑制するために、現状では
シュウ酸を添加し、抽出されないシュウ酸錯体を形成す
ることで抑制することが検討されている。しかし実験の
結果、図９に示すように、従来のＰＵＲＥＸプロセスか
ら排出される分離抽出廃液では、シュウ酸をある程度
（例えば０．５mol/l)まで添加しても沈殿が生じない
が、図１０に示すように分離抽出廃液を約１０倍の塩濃
度になるように濃縮した高レベル廃液では、シュウ酸を
わずか（例えば０．２mol/l ）添加しても多量の沈殿物
が発生する問題が明らかとなった。従って、シュウ酸を
廃液に添加するＴＲＵＥＸプロセスでは、高レベル廃液
条件の場合Ｚｒ、Ｍｏ等の抽出を抑制することができ
ず、高純度のアクチノイド（Ｕ、Ａｍ、Ｃｍ、Ｐｕ、Ｎ
ｐ）を効率的に回収できない問題点があった。However, such a TRU
By the CMPO contained in the solvent of the EX process, the actinides (U, Am, Cm, Pu, N) that are the elements to be extracted are
In addition to p, etc., Zr (zirconium), M which becomes an impurity
There is a problem that o (molybdenum) and the like are also extracted. In order to suppress the extraction of these impurities, it is currently being studied to add oxalic acid to form an unextracted oxalic acid complex. However, as a result of the experiment, as shown in FIG. 9, in the separation and extraction waste liquid discharged from the conventional PUREX process, precipitation does not occur even if oxalic acid is added to some extent (for example, 0.5 mol / l). As shown in Fig. 2, in the high-level waste liquid obtained by concentrating the separated extraction waste liquid to have a salt concentration of about 10 times, there is a problem that a large amount of precipitate is generated even if a small amount (for example, 0.2 mol / l) of oxalic acid is added. It became clear. Therefore, in the TRUEX process in which oxalic acid is added to the waste liquid, the extraction of Zr, Mo, etc. cannot be suppressed under the high-level waste liquid condition, and high-purity actinoids (U, Am, Cm, Pu, N, etc.) cannot be suppressed.
There was a problem that p) could not be recovered efficiently.
【０００６】本発明はかかる問題点を解決するために創
案されたものである。すなわち、本発明の目的は、沈殿
の生成をともなわないでＺｒ（ジルコニウム）及びＭｏ
（モリブデン）の抽出を効果的に抑制でき、高純度のア
クチノイド（Ｕ、Ａｍ、Ｃｍ、Ｐｕ、Ｎｐ等）を効率的
に抽出することができる高塩濃度対応型溶媒抽出方法を
提供することにある。The present invention was devised to solve such problems. That is, the object of the present invention is to produce Zr (zirconium) and Mo without the formation of precipitates.
To provide a high salt concentration compatible solvent extraction method capable of effectively suppressing the extraction of (molybdenum) and efficiently extracting high-purity actinoids (U, Am, Cm, Pu, Np, etc.). is there.
【０００７】[0007]
【課題を解決するための手段】本発明によれば、使用済
核燃料の高レベル廃液とＴＢＰ及びＣＭＰＯを含む溶媒
とを混合し静置して有機相と水相に分離し、有機相から
超ウラン元素を回収する溶媒抽出方法において、廃液中
にキレート形成作用を有するカルボン酸を含み、これに
より、ジルコニウム及びモリブデンの抽出を抑制する、
ことを特徴とする超ウラン元素を溶媒抽出する方法が提
供される。According to the present invention, a high-level waste liquid of spent nuclear fuel and a solvent containing TBP and CMPO are mixed and allowed to stand to separate into an organic phase and an aqueous phase. In a solvent extraction method for recovering uranium element, a waste solution contains a carboxylic acid having a chelating action, thereby suppressing the extraction of zirconium and molybdenum,
A method for solvent extraction of transuranium element is provided.
【０００８】本発明の好ましい実施例によれば、前記カ
ルボン酸は、リンゴ酸、スルホサリチル酸、スルファミ
ン酸、クエン酸、ギ酸、グリコール酸、マロン酸、コハ
ク酸、アジピン酸のいずれか又はこれらの混合物であ
り、中でもクエン酸やギ酸が好ましいカルボン酸といえ
る。また、前記有機相と水相との体積比（有機相／水
相）は約２．３以上であることが好ましい。According to a preferred embodiment of the present invention, the carboxylic acid is malic acid, sulfosalicylic acid, sulfamic acid, citric acid, formic acid, glycolic acid, malonic acid, succinic acid, adipic acid, or a mixture thereof. Among them, citric acid and formic acid are preferable carboxylic acids. The volume ratio of the organic phase and the aqueous phase (organic phase / aqueous phase) is preferably about 2.3 or more.
【０００９】[0009]
【作用】本発明の発明者等は、上述した新規の問題を解
決するため、通常のイオン結合と異なるキレート構造に
着目し、キレート形成作用を有する種々のカルボン酸を
試験し、沈殿の形成をともなわないでジルコニウム及び
モリブデンの抽出を効果的に抑制できる条件を発見し
た。本発明はかかる新規の知見に基づくものである。In order to solve the above-mentioned novel problems, the inventors of the present invention focused on a chelate structure different from a normal ionic bond, tested various carboxylic acids having a chelate-forming action, and confirmed the formation of a precipitate. We have found the conditions that can effectively suppress the extraction of zirconium and molybdenum. The present invention is based on this novel finding.
【００１０】すなわち、本発明によれば、ＴＢＰ及びＣ
ＭＰＯを含む溶媒とキレート形成作用を有するカルボン
酸を添加した廃液を混ぜることにより、廃液中のジルコ
ニウム及びモリブデンの抽出を抑制して、混合静置後の
有機相から高純度の超ウラン元素等アクチノイドを回収
することができる。カルボン酸としては、クエン酸、ギ
酸及びこれらの混酸もしくは他のカルボン酸との混酸が
効果的である。また、有機相と水相との体積比（有機相
／水相）を約２．３〜約２．６にすることにより、第三
相を形成することなく有機相の比率を下げ（従来は２．
６以上）、これにより高価な溶媒の使用量を低減するこ
とができる。That is, according to the present invention, TBP and C
By mixing a solvent containing MPO and a waste liquid added with a carboxylic acid having a chelate-forming effect, the extraction of zirconium and molybdenum in the waste liquid is suppressed, and a highly pure actinide such as transuranium element from the organic phase after mixing and standing. Can be recovered. As the carboxylic acid, citric acid, formic acid, a mixed acid thereof or a mixed acid with another carboxylic acid is effective. Further, by setting the volume ratio of the organic phase and the aqueous phase (organic phase / aqueous phase) to about 2.3 to about 2.6, the ratio of the organic phase can be reduced without forming the third phase (conventionally, 2.
6 or more), whereby the amount of expensive solvent used can be reduced.
【００１１】[0011]
【実施例】以下、本発明の好ましい実施例を図面を参照
して説明する。図１は、本発明の方法を実施するための
溶媒抽出装置の構成図である。この図において、溶媒抽
出装置は、使用済核燃料の高レベル廃液１とＴＢＰ及び
ＣＭＰＯを含む溶媒２とを混合するための混合容器１２
と、混合液を静置して有機相Ｏと水相Ａに分離する静置
容器１４（セトラ）と、静置容器１４からの排出流量を
調節する調節容器１６（レギュレータ）とを備えてい
る。図１において混合容器１２は中空円筒状の容器であ
り、内部の混合液３を攪拌する攪拌器１１（ミキサー）
が垂直に設置されている。また、混合容器１２の上端に
は高レベル廃液１と溶媒２とが対向して流入する流入路
１２ａ、１２ｂが設けられ、かつ混合容器１２の中間部
分には混合液３を静置容器１４に導くダクト１３が設け
られている。更に、静置容器１４の上端には静置により
分離した有機相Ｏを流出させる流出路１４ａが設けら
れ、かつ静置容器１４の下端部分には水相Ａを調節容器
１６に導くダクト１５が設けられている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a solvent extraction apparatus for carrying out the method of the present invention. In this figure, the solvent extraction device is a mixing container 12 for mixing a high-level waste liquid 1 of spent nuclear fuel with a solvent 2 containing TBP and CMPO.
And a stationary container 14 (Setra) for allowing the mixed solution to stand still and separating it into an organic phase O and an aqueous phase A, and an adjusting container 16 (regulator) for adjusting the discharge flow rate from the stationary container 14. . In FIG. 1, a mixing container 12 is a hollow cylindrical container, and a stirrer 11 (mixer) for stirring the mixed liquid 3 inside.
Is installed vertically. In addition, inflow passages 12 a and 12 b through which the high-level waste liquid 1 and the solvent 2 face each other are provided at the upper end of the mixing container 12, and the mixed liquid 3 is placed in the stationary container 14 at an intermediate portion of the mixing container 12. A guiding duct 13 is provided. Further, an outflow passage 14a for flowing out the organic phase O separated by stationary is provided at the upper end of the stationary container 14, and a duct 15 for guiding the water phase A to the adjustment container 16 is provided at the lower end of the stationary container 14. It is provided.
【００１２】上述した構成により、混合容器１２に高レ
ベル廃液１と溶媒２を対向して流入させ、混合容器１２
内で攪拌器１１により高レベル廃液１と溶媒２を混合
し、混合液３をダクト１３を介して静置容器１４に導
き、静置容器１４内で混合液を静置して有機相Ｏと水相
Ａに分離することができる。静置容器１４内の有機相Ｏ
は、高レベル廃液１から抽出された成分（例えば超ウラ
ン元素等）が溶け込んだ溶媒２であり、流出路１４ａを
介して有機相Ｏを逆抽出設備等（図示せず、図８参照）
に導き、そこで有機相から超ウラン元素等を回収するこ
とができる。また、水相Ａは抽出成分が抜けた高レベル
廃液１であり調節容器１６の流出路１６ａを介してガラ
ス固化装置等（図示せず、図８参照）に供給することが
できる。With the above-described structure, the high-level waste liquid 1 and the solvent 2 are allowed to flow into the mixing container 12 so as to face each other, and the mixing container 12
The high-level waste liquid 1 and the solvent 2 are mixed by a stirrer 11 inside, the mixed liquid 3 is introduced into the stationary container 14 through the duct 13, and the mixed liquid is stationary in the stationary container 14 to form an organic phase O. The aqueous phase A can be separated. Organic phase O in stationary container 14
Is a solvent 2 in which a component extracted from the high-level waste liquid 1 (for example, transuranium element, etc.) is dissolved, and the organic phase O is back-extracted through the outflow passage 14a (not shown, see FIG. 8).
Where the transuranic element and the like can be recovered from the organic phase. Further, the aqueous phase A is the high-level waste liquid 1 from which the extracted components have been removed, and can be supplied to the vitrification device and the like (not shown, see FIG. 8) via the outflow passage 16a of the adjusting container 16.
【００１３】なお、以下、有機相Ｏと水相Ａの体積比
（有機相／水相）を「Ｏ／Ａ比」と呼び、有機相Ｏと水
相Ａの両方に特定の成分が平衡状態で溶けた場合のモル
比（有機相内のモル数／水相内のモル数）を「分配比」
と呼ぶ。Hereinafter, the volume ratio of the organic phase O and the aqueous phase A (organic phase / aqueous phase) is referred to as "O / A ratio", and a specific component is in an equilibrium state in both the organic phase O and the aqueous phase A. "Distribution ratio" is the molar ratio (moles in the organic phase / moles in the aqueous phase) when dissolved in
Call.
【００１４】図２は、図１の装置を用い、キレート形成
作用を有する種々のカルボン酸を溶媒に混ぜてその抽出
抑制効果を試験した結果である。この試験ではカルボン
酸として、リンゴ酸、スルホサリチル酸、スルファミン
酸、クエン酸、ギ酸、グリコール酸、マロン酸、コハク
酸、アジピン酸を使用し、従来のシュウ酸と比較した。
また、この試験では放射性のある超ウラン元素（ＴＲＵ
元素）の替わりに特性が近いランタニドであるＮｄ（ネ
オジム）を使用し、Ｏ／Ａ比１．０、温度２５℃、添加
量０．２ｍｏｌ／ｌ（リットル）の同一条件で試験し
た。FIG. 2 shows the results of testing the effect of inhibiting the extraction of various carboxylic acids having a chelating action by mixing them in a solvent using the apparatus of FIG. In this test, malic acid, sulfosalicylic acid, sulfamic acid, citric acid, formic acid, glycolic acid, malonic acid, succinic acid and adipic acid were used as carboxylic acids and compared with conventional oxalic acid.
In this test, radioactive transuranium element (TRU)
Instead of (element), Nd (neodymium), which is a lanthanide having similar characteristics, was used and tested under the same conditions of O / A ratio of 1.0, temperature of 25 ° C., and addition amount of 0.2 mol / l (liter).
【００１５】図２から明らかなように、従来の抽出抑制
であるシュウ酸では、Ｎｄ（ネオジム）、Ｚｒ（ジルコ
ニウム）、Ｍｏ（モリブデン）のすべてが沈殿を生成し
たのに対し、試験したカルボン酸のすべてが沈殿を生成
することなく、抽出抑制剤として使用できることが確認
された。特に、クエン酸は、模擬ＴＲＵ元素であるＮｄ
の分配比が高くかつＺｒ及びＭｏの分配比が低いことか
ら、抽出抑制効果が大きいことがわかる。As is apparent from FIG. 2, in the conventional extraction-inhibiting oxalic acid, Nd (neodymium), Zr (zirconium), and Mo (molybdenum) all produced precipitates, whereas the tested carboxylic acid. It was confirmed that all of the above can be used as extraction inhibitors without producing a precipitate. In particular, citric acid is a simulated TRU element, Nd.
It can be seen that the extraction suppression effect is large because the distribution ratio of is high and the distribution ratio of Zr and Mo is low.
【００１６】図３は、クエン酸とギ酸について、Ｏ／Ａ
比２〜３、温度２５℃、添加量１．０ｍｏｌ／ｌの場合
の図２と同様の試験結果である。この図から、添加量を
多くすれば、クエン酸の他にギ酸も、Ｎｄの分配比が高
くかつＺｒ及びＭｏの分配比が低いことから、抽出抑制
効果が大きいことがわかる。図４は、ＣＭＰＯ濃度と分
配比との関係を示す図である。この図からＣＭＰＯ濃度
を通常の約０．２ｍｏｌ／ｌから約０．４ｍｏｌ／ｌ程
度まで約２倍に増やすことにより、抽出対象のＮｄ（ネ
オジム）の分配比を７〜８倍に高めることができること
がわかる。また、この範囲でＺｒ及びＭｏの分配比はほ
ぼゼロであり、不純物の抽出は抑制することができる。FIG. 3 shows O / A for citric acid and formic acid.
The test results are the same as those in FIG. 2 when the ratio is 2 to 3, the temperature is 25 ° C., and the addition amount is 1.0 mol / l. From this figure, it is understood that when the addition amount is increased, not only citric acid but also formic acid has a high distribution ratio of Nd and a low distribution ratio of Zr and Mo, so that the extraction suppression effect is large. FIG. 4 is a diagram showing the relationship between the CMPO concentration and the distribution ratio. From this figure, it is possible to increase the distribution ratio of Nd (neodymium) to be extracted to 7 to 8 times by increasing the CMPO concentration from about 0.2 mol / l to about 0.4 mol / l to about 2 times. I know that I can do it. Further, in this range, the distribution ratio of Zr and Mo is almost zero, and the extraction of impurities can be suppressed.
【００１７】図５及び図６は、クエン酸を添加した場合
（図５）と添加しない場合（図６）のＯ／Ａ比と液量と
の関係を示す図である。この図において、○印は廃液相
（水相Ｏ）を示し、▲印は、水相Ｏと有機相Ａとの間に
できた第三相を示している。この第三相が形成される
と、上述した静置容器１４における分離が不完全とな
り、プロセス全体の効率が悪化する問題が生じる。従っ
て、図５と図６との比較から、クエン酸を添加しない場
合（図６）には、Ｏ／Ａ比を２．６以下にはできなかっ
たのに対して、クエン酸を添加する（図５）ことによ
り、第三相を形成することなくＯ／Ａ比を約２．３まで
下げることができ、有機相Ａの比率を下げ、高価な溶剤
の使用量を低減することができることがわかる。FIGS. 5 and 6 are diagrams showing the relationship between the O / A ratio and the liquid amount when citric acid is added (FIG. 5) and when citric acid is not added (FIG. 6). In this figure, the ∘ mark indicates the waste liquid phase (water phase O), and the ▴ mark indicates the third phase formed between the water phase O and the organic phase A. When this third phase is formed, the separation in the stationary container 14 described above becomes incomplete, and the efficiency of the entire process deteriorates. Therefore, from the comparison between FIG. 5 and FIG. 6, when the citric acid was not added (FIG. 6), the O / A ratio could not be reduced to 2.6 or less, while the citric acid was added ( As a result, the O / A ratio can be reduced to about 2.3 without forming the third phase, the ratio of the organic phase A can be reduced, and the amount of expensive solvent used can be reduced. Recognize.
【００１８】従って、上述した本発明の方法によれば、
ＴＢＰ及びＣＭＰＯを含む溶媒にキレート形成作用を有
するカルボン酸を添加した廃液を混ぜることにより、ジ
ルコニウム及びモリブデンの抽出を抑制して、混合静置
後の有機相から超ウラン元素を回収することができる。
特に、カルボン酸は、クエン酸やギ酸が効果的である。
また、有機相と水相との体積比（有機相／水相）を約
２．３〜約２．６にすることにより、第三相を形成する
ことなく有機相の比率を下げ（従来は２．６以上）、こ
れにより高価な溶剤の使用量を低減することができる。Therefore, according to the method of the present invention described above,
By mixing a waste liquid in which a carboxylic acid having a chelate forming action is added to a solvent containing TBP and CMPO, extraction of zirconium and molybdenum can be suppressed, and transuranium element can be recovered from an organic phase after mixing and standing. .
Particularly, as the carboxylic acid, citric acid or formic acid is effective.
Further, by setting the volume ratio of the organic phase and the aqueous phase (organic phase / aqueous phase) to about 2.3 to about 2.6, the ratio of the organic phase can be reduced without forming the third phase (conventionally, 2.6 or more), whereby the amount of expensive solvent used can be reduced.
【００１９】なお、本発明は上述した実施例に限定され
ず、本発明の要旨を逸脱しない範囲で種々変更できるこ
とは勿論である。The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.
【００２０】[0020]
【発明の効果】上述したように、本発明の超ウラン元素
の溶媒抽出方法は、沈殿の形成をともなわないでＺｒ
（ジルコニウム）及びＭｏ（モリブデン）の抽出を効果
的に抑制でき、高純度のアクチノイド（Ｕ、Ａｍ、Ｃ
ｍ、Ｐｕ、Ｎｐ等）を効率的に抽出することができる、
という優れた効果を有する。INDUSTRIAL APPLICABILITY As described above, the solvent extraction method for transuranium elements according to the present invention does not involve the formation of a precipitate, but Zr.
Extraction of (zirconium) and Mo (molybdenum) can be effectively suppressed, and high-purity actinides (U, Am, C
m, Pu, Np, etc.) can be efficiently extracted,
It has an excellent effect.
【図１】本発明の方法を実施するための溶媒抽出装置の
構成図である。FIG. 1 is a block diagram of a solvent extraction apparatus for carrying out the method of the present invention.
【図２】種々のカルボン酸の抽出抑制効果の試験結果で
ある。FIG. 2 shows the test results of the extraction inhibitory effect of various carboxylic acids.
【図３】クエン酸とギ酸についての図２と同様の試験結
果である。FIG. 3 is the same test result as in FIG. 2 for citric acid and formic acid.
【図４】ＣＭＰＯ濃度と分配比との関係を示す図であ
る。FIG. 4 is a diagram showing the relationship between CMPO concentration and distribution ratio.
【図５】クエン酸を添加した場合のＯ／Ａ比と液量との
関係を示す図である。FIG. 5 is a diagram showing a relationship between an O / A ratio and a liquid amount when citric acid is added.
【図６】クエン酸を添加しない場合のＯ／Ａ比と液量と
の関係を示す図である。FIG. 6 is a diagram showing a relationship between an O / A ratio and a liquid amount when citric acid is not added.
【図７】群分離プロセスの説明図である。FIG. 7 is an explanatory diagram of a group separation process.
【図８】ＴＲＵＥＸプロセスのプロセスフロー図であ
る。FIG. 8 is a process flow diagram of the TRUEX process.
【図９】低レベル廃液におけるシュウ酸添加量と沈殿量
との関係図である。FIG. 9 is a diagram showing the relationship between the amount of oxalic acid added and the amount of precipitation in a low-level waste liquid.
【図１０】高レベル廃液におけるシュウ酸添加量と沈殿
量との関係図である。FIG. 10 is a relationship diagram between the amount of oxalic acid added and the amount of precipitation in the high-level waste liquid.
１ 高レベル廃液 ２ 溶媒 ３ 混合液 １１ 攪拌器 １２ 混合容器 １２ａ、１２ｂ 流入路 １３、１５ ダクト １４ 静置容器（セトラ） １４ａ 流出路 １６ 調節容器 １６ａ 流出路 Ａ 水相 Ｏ 有機相 1 High-level waste liquid 2 Solvent 3 Mixed liquid 11 Stirrer 12 Mixing container 12a, 12b Inflow path 13, 15 Duct 14 Stationary container (Setra) 14a Outflow path 16 Control vessel 16a Outflow path A Water phase O Organic phase
Claims (3)
びＣＭＰＯを含む溶媒とを混合し静置して有機相と水相
に分離し、有機相から超ウラン元素等を回収する溶媒抽
出方法において、 廃液中に超ウラン元素についてキレート形成作用を有す
るカルボン酸を含み、これにより、ジルコニウム及びモ
リブデンの抽出を抑制する、ことを特徴とする超ウラン
元素を溶媒抽出する方法。1. A solvent extraction method comprising mixing a high-level waste liquid of spent nuclear fuel with a solvent containing TBP and CMPO, allowing the mixture to stand, separating the organic phase and the aqueous phase, and recovering transuranic elements from the organic phase. A method for solvent-extracting a transuranic element, characterized in that the waste liquid contains a carboxylic acid having a chelating action for a transuranic element, thereby suppressing the extraction of zirconium and molybdenum.
リチル酸、スルファミン酸、クエン酸、ギ酸、グリコー
ル酸、マロン酸、コハク酸、アジピン酸のいずれか１つ
又はこれらの混合物である、ことを特徴とする請求項１
に記載の超ウラン元素を溶媒抽出する方法。2. The carboxylic acid is any one of malic acid, sulfosalicylic acid, sulfamic acid, citric acid, formic acid, glycolic acid, malonic acid, succinic acid, adipic acid, or a mixture thereof. Claim 1
The method for solvent extraction of transuranic element according to 1.
水相）が約２．３以上である、ことを特徴とする請求項
１に記載の超ウラン元素を溶媒抽出する方法。3. A volume ratio (organic phase / aqueous phase) of the organic phase and the aqueous phase.
The method for solvent-extracting transuranic elements according to claim 1, wherein the aqueous phase) is about 2.3 or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14280094A JPH0815483A (en) | 1994-06-24 | 1994-06-24 | Method for solvent extraction of transuranium elements |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14280094A JPH0815483A (en) | 1994-06-24 | 1994-06-24 | Method for solvent extraction of transuranium elements |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0815483A true JPH0815483A (en) | 1996-01-19 |
Family
ID=15323930
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14280094A Pending JPH0815483A (en) | 1994-06-24 | 1994-06-24 | Method for solvent extraction of transuranium elements |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0815483A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997025721A1 (en) * | 1996-01-08 | 1997-07-17 | British Nuclear Fuels Plc | Recovery of actinides |
| WO1999014765A1 (en) * | 1997-09-13 | 1999-03-25 | British Nuclear Fuels Plc | GLYCOLIC AND PYRUVIC ACIDS AS Np(IV) STRIPPING AGENTS |
| JP2013509574A (en) * | 2009-10-28 | 2013-03-14 | コミッサリア ア ロンネルジー アトミック エ オ ゾンネルジー ザルテルナティーフ | Use of certain chemical elements to inhibit the formation of precipitates containing zirconium molybdate in aqueous solutions containing elemental molybdenum and elemental zirconium |
| KR101386704B1 (en) * | 2013-02-04 | 2014-04-18 | 한국과학기술연구원 | Separation method of zirconium and hafnium by solvent extraction process |
-
1994
- 1994-06-24 JP JP14280094A patent/JPH0815483A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1997025721A1 (en) * | 1996-01-08 | 1997-07-17 | British Nuclear Fuels Plc | Recovery of actinides |
| WO1999014765A1 (en) * | 1997-09-13 | 1999-03-25 | British Nuclear Fuels Plc | GLYCOLIC AND PYRUVIC ACIDS AS Np(IV) STRIPPING AGENTS |
| JP2013509574A (en) * | 2009-10-28 | 2013-03-14 | コミッサリア ア ロンネルジー アトミック エ オ ゾンネルジー ザルテルナティーフ | Use of certain chemical elements to inhibit the formation of precipitates containing zirconium molybdate in aqueous solutions containing elemental molybdenum and elemental zirconium |
| KR101386704B1 (en) * | 2013-02-04 | 2014-04-18 | 한국과학기술연구원 | Separation method of zirconium and hafnium by solvent extraction process |
| US8778288B1 (en) | 2013-02-04 | 2014-07-15 | Korea Institute Of Science And Technology | Separation method of zirconium and hafnium by solvent extraction process |
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