JP2549532B2 - Precipitation separation method for transuranium elements - Google Patents
Precipitation separation method for transuranium elementsInfo
- Publication number
- JP2549532B2 JP2549532B2 JP62253895A JP25389587A JP2549532B2 JP 2549532 B2 JP2549532 B2 JP 2549532B2 JP 62253895 A JP62253895 A JP 62253895A JP 25389587 A JP25389587 A JP 25389587A JP 2549532 B2 JP2549532 B2 JP 2549532B2
- Authority
- JP
- Japan
- Prior art keywords
- waste liquid
- separation method
- neptunium
- oxalate
- precipitation separation
- 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.)
- Expired - Fee Related
Links
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は超ウラン元素の沈澱分離方法に関する。より
詳細に述べれば、本発明は、使用済核燃料の再処理に伴
って発生する高レベル放射性廃液又はアルファ放射性廃
液にシュウ酸又はシュウ酸塩を添加して、超ウラン元素
をシュウ酸塩沈澱として分離する操作において、予め廃
液にアスコルビン酸又はヒドロキシルアミンを共存させ
ることを特徴とする超ウラン元素の沈澱分離方法に関す
る。TECHNICAL FIELD The present invention relates to a method for precipitation separation of transuranium elements. More specifically, the present invention adds oxalic acid or oxalate to the high-level radioactive waste liquid or alpha radioactive waste liquid generated by the reprocessing of spent nuclear fuel to convert trans-uranium elements into oxalate precipitates. The present invention relates to a method for precipitating and separating a transuranic element, wherein ascorbic acid or hydroxylamine is allowed to coexist in a waste liquid in the separation operation.
（従来の技術） 高レベル放射性廃液やアルファ放射性廃液に含まれる
ネプツニウム、プルトニウム、アメリシウム、キュリウ
ムなどの超ウラン元素を分離するための技術開発は、廃
棄物の処理処分における長期にわたる安全性向上の観点
から、また，超ウラン元素を資源として有効に利用しょ
うとの観点から実施されてきた。安全性向上の観点から
は、最近では超ウラン元素のうちでも特にネプツニウム
の効率的な分離法の開発が必要となっている。(Prior art) Technical development for separating transuranic elements such as neptunium, plutonium, americium, and curium contained in high-level radioactive waste liquid and alpha radioactive waste liquid is aimed at improving long-term safety in waste disposal. And from the viewpoint of effectively using transuranium elements as resources. From the viewpoint of improving safety, it has recently become necessary to develop an efficient separation method for neptunium among transuranic elements.
超ウラン元素の分離方法としては、多量の放射性廃液
を連続的に処理できることから、有機溶剤を使用する抽
出分離法がもっぱら開発されているが，この方法では溶
媒の劣化による新たな廃液の発生という問題がある。こ
れに対して、シュウ酸又はシュウ酸塩を使用する沈澱分
離法は濾過操作に問題があるものの、使用後のシュウ酸
は容易に水と二酸化炭素に分解することができる。As a method for separating transuranium elements, an extraction separation method using an organic solvent has been exclusively developed because a large amount of radioactive waste liquid can be continuously treated, but this method is called a new waste liquid generation due to deterioration of the solvent. There's a problem. On the other hand, although the precipitation separation method using oxalic acid or oxalate has a problem in the filtration operation, oxalic acid after use can be easily decomposed into water and carbon dioxide.
これまでに開発されてきた高レベル放射性廃液やアル
ファ放射性廃液からの超ウラン元素のシュウ酸塩沈澱分
離法では、酸濃度調整を行った廃液に直接シュウ酸又は
シュウ酸塩を添加し、超ウラン元素を沈澱として分離し
ている。この方法の欠点は一般に廃液中でＶ価、イオン
形としてはNPO2 +の状態で存在するネプツニウムを効率
的に沈澱させることが出来ないという問題である。In the oxalate precipitation separation method of transuranic elements from high-level radioactive waste liquid and alpha radioactive waste liquid that has been developed so far, oxalic acid or oxalate salt is directly added to the waste liquid whose acid concentration has been adjusted. The element is separated as a precipitate. The drawback of this method is that it is generally not possible to efficiently precipitate Neptunium which has V valence in the waste liquid and is in the NPO 2 + state as an ionic form.
（発明が解決しようとする問題点） 本発明の目的は、この欠点を改良する方法、即ち超ウ
ラン元素のうちでも特にネプツニウムの沈澱率を高める
方法を提供することである。(Problems to be Solved by the Invention) An object of the present invention is to provide a method for improving this drawback, that is, a method for increasing the precipitation rate of neptunium among transuranic elements.
本発明によれば、シュウ酸やシュウ酸塩による沈澱操
作に先がけて、廃液にアスコルビン酸又はヒドロキシル
アミンを添加するとネプツニウムの沈澱率が増加する。According to the present invention, the precipitation rate of neptunium increases when ascorbic acid or hydroxylamine is added to the waste liquid prior to the precipitation operation with oxalic acid or oxalate.
アスコルビン酸又はヒドロキシルアミンを添加するこ
との意味はネプツニウムをＶ価（NPO2 +）からIV価（NP
4+）へ還元することである。この際，アスコルビン酸や
ヒドロキシルアミンの廃液中濃度はNPO2 +濃度の３倍以
上とすることが適切である。なお，ネプツニウム以外の
超ウラン元素については、その殆どが廃液中でIII価又
はIV価の陽イオンとして存在することから，シュウ酸塩
として沈澱することに特に問題はない。The meaning of adding ascorbic acid or hydroxylamine is to change neptunium from V value (NPO 2 + ) to IV value (NP
4+ ). At this time, it is appropriate that the concentration of ascorbic acid or hydroxylamine in the waste liquid is at least 3 times the concentration of NPO 2 + . It should be noted that since most of the transuranium elements other than neptunium exist as cations of III or IV in the waste liquid, there is no particular problem in precipitating them as oxalates.
（実施例） 次に実施例を示して本発明をさらに具体的に説明す
る。但し，本発明は本実施例によって限定されるもので
はない。(Example) Next, an Example is shown and this invention is demonstrated more concretely. However, the present invention is not limited to this embodiment.
実施例 高レベル放射性廃液を模擬した第１表に示すような元
素組成の溶液をバイアルびんに237NP(NPO2 +)の溶液とア
スコルビン酸又は塩化ヒドロキシルアミン溶液を添加し
たのち、結晶状のシュウ酸を1mol/l溶液となるように加
えた。ただちにこの試料を25℃に設定してあるエアバス
中に入れ、回転ローラー上で所定時間拡はんした。試料
を取出して遠心分離機（3000rpm X3分）にかけた後、上
澄液の1mlをサンプリングし、237NPの放射能強度をGe半
導体検出器で測定することによりネプツニウムの沈澱率
を求めた。Example A solution having an elemental composition as shown in Table 1 simulating a high-level radioactive liquid waste was added to a vial bottle with a solution of 237 NP (NPO 2 + ) and a solution of ascorbic acid or hydroxylamine chloride, and then crystalline shu Acid was added to give a 1 mol / l solution. Immediately, this sample was put in an air bath set at 25 ° C., and spread on a rotating roller for a predetermined time. After taking out the sample and centrifuging it (3000 rpm x 3 minutes), 1 ml of the supernatant was sampled, and the precipitation rate of neptunium was determined by measuring the radioactivity intensity of 237 NP with a Ge semiconductor detector.
還元剤を添加した場合及びしない場合の拡はん時間と
ネプツニウム沈澱率（％）の関係を第２表に示した。Table 2 shows the relationship between the spreading time and the neptunium precipitation rate (%) with and without the addition of the reducing agent.
第２表から明らかなように、アスコルビン酸や塩化ヒ
ドロキシルアミンなどの還元剤を添加しない場合におい
てもネプツニウムの沈澱率は拡はん時間が長くなるにつ
れて徐々に増加するが、塩化ヒドロキシルアミン添加の
場合は60分以内で、アスコルビン酸添加の場合は５分以
内に99％以上となった。塩化ヒドロキシルアミンの場合
には、溶液を加熱することにより、より短時間で高いネ
プツニウムの沈澱率が得られると考えられる。As is clear from Table 2, the precipitation rate of neptunium gradually increases as the spreading time increases even when a reducing agent such as ascorbic acid or hydroxylamine chloride is not added. Within 60 minutes and with ascorbic acid addition within 5 minutes 99% or more. In the case of hydroxylamine chloride, it is believed that by heating the solution, a higher precipitation rate of neptunium can be obtained in a shorter time.
注：数値は模擬廃液中の各元素のモル濃度であり、該溶
液は2.0mol/lの硝酸溶液として与えられている。 Note: The numerical value is the molar concentration of each element in the simulated waste liquid, and the solution is given as a 2.0 mol / l nitric acid solution.
Claims (1)
レベル放射性廃液又はアルファ放射性廃液にシュウ酸又
はシュウ酸塩を添加して、超ウラン元素をシュウ酸塩と
して沈澱分離する操作において、予め廃液にアスコルビ
ン酸又はヒドロキシルアミンを共存させることを特徴と
する超ウラン元素の沈澱分離方法。1. An operation of adding oxalic acid or oxalate to a high-level radioactive waste liquid or alpha radioactive waste liquid generated by reprocessing of spent nuclear fuel to precipitate and separate transuranic element as an oxalate salt, A method for precipitating and separating transuranic element, which comprises coexisting ascorbic acid or hydroxylamine in the waste liquid in advance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62253895A JP2549532B2 (en) | 1987-10-09 | 1987-10-09 | Precipitation separation method for transuranium elements |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62253895A JP2549532B2 (en) | 1987-10-09 | 1987-10-09 | Precipitation separation method for transuranium elements |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0196019A JPH0196019A (en) | 1989-04-14 |
| JP2549532B2 true JP2549532B2 (en) | 1996-10-30 |
Family
ID=17257588
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62253895A Expired - Fee Related JP2549532B2 (en) | 1987-10-09 | 1987-10-09 | Precipitation separation method for transuranium elements |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2549532B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03102298A (en) * | 1989-09-18 | 1991-04-26 | Japan Atom Energy Res Inst | Recovery of palladium |
| JP2809819B2 (en) * | 1990-06-14 | 1998-10-15 | 株式会社東芝 | Group separation method for high-level radioactive liquid waste |
| KR100456778B1 (en) * | 2002-09-30 | 2004-11-10 | 현대모비스 주식회사 | structure of thwarting dirt of indicator and slider |
| JP4604226B2 (en) * | 2005-11-16 | 2011-01-05 | 独立行政法人 日本原子力研究開発機構 | Method for quantitative extraction and back extraction of neptunium in nitric acid solution with DGA (diglycolamide) compound |
| FR2940267B1 (en) * | 2008-12-19 | 2011-12-09 | Commissariat Energie Atomique | PROCESS FOR THE PREPARATION OF ACTINIDE OXALATE (S) AND PREPARATION OF ACTINIDE COMPOUND (S) |
-
1987
- 1987-10-09 JP JP62253895A patent/JP2549532B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0196019A (en) | 1989-04-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |