JPH07109438B2 - Solvent recycling method in nuclear fuel reprocessing - Google Patents
Solvent recycling method in nuclear fuel reprocessingInfo
- Publication number
- JPH07109438B2 JPH07109438B2 JP13834989A JP13834989A JPH07109438B2 JP H07109438 B2 JPH07109438 B2 JP H07109438B2 JP 13834989 A JP13834989 A JP 13834989A JP 13834989 A JP13834989 A JP 13834989A JP H07109438 B2 JPH07109438 B2 JP H07109438B2
- Authority
- JP
- Japan
- Prior art keywords
- dodecane
- solvent
- tbp
- amount
- organic solvent
- 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
- 238000000034 method Methods 0.000 title claims description 33
- 239000002904 solvent Substances 0.000 title claims description 19
- 239000003758 nuclear fuel Substances 0.000 title claims description 14
- 238000012958 reprocessing Methods 0.000 title claims description 14
- 238000004064 recycling Methods 0.000 title claims description 8
- SNRUBQQJIBEYMU-UHFFFAOYSA-N dodecane Chemical compound CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 claims description 88
- 238000005406 washing Methods 0.000 claims description 33
- 238000000605 extraction Methods 0.000 claims description 31
- 239000003960 organic solvent Substances 0.000 claims description 26
- 239000003085 diluting agent Substances 0.000 claims description 24
- 239000000463 material Substances 0.000 claims description 8
- 239000007864 aqueous solution Substances 0.000 claims description 7
- 239000012044 organic layer Substances 0.000 claims description 5
- 239000000243 solution Substances 0.000 claims description 5
- 239000002915 spent fuel radioactive waste Substances 0.000 claims description 4
- STCOOQWBFONSKY-UHFFFAOYSA-N tributyl phosphate Chemical compound CCCCOP(=O)(OCCCC)OCCCC STCOOQWBFONSKY-UHFFFAOYSA-N 0.000 description 30
- 238000001256 steam distillation Methods 0.000 description 16
- 239000010887 waste solvent Substances 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 238000000638 solvent extraction Methods 0.000 description 7
- 239000010410 layer Substances 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 238000000926 separation method Methods 0.000 description 6
- 238000004821 distillation Methods 0.000 description 5
- 238000004140 cleaning Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 3
- FJTUUPVRIANHEX-UHFFFAOYSA-N butan-1-ol;phosphoric acid Chemical compound CCCCO.OP(O)(O)=O FJTUUPVRIANHEX-UHFFFAOYSA-N 0.000 description 3
- 230000004992 fission Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000005292 vacuum distillation Methods 0.000 description 3
- 108050001327 26S Proteasome regulatory subunit 6B Proteins 0.000 description 2
- 102100029511 26S proteasome regulatory subunit 6B Human genes 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 229910052778 Plutonium Inorganic materials 0.000 description 2
- 229910052770 Uranium Inorganic materials 0.000 description 2
- 238000013142 basic testing Methods 0.000 description 2
- BNMJSBUIDQYHIN-UHFFFAOYSA-N butyl dihydrogen phosphate Chemical class CCCCOP(O)(O)=O BNMJSBUIDQYHIN-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000012459 cleaning agent Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005194 fractionation Methods 0.000 description 1
- 239000002927 high level radioactive waste Substances 0.000 description 1
- 238000000622 liquid--liquid extraction Methods 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 1
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)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、使用済燃料の溶媒抽出法による再処理におけ
る有機溶媒のリサイクル方法に関するものである。再処
理工程で使用したTBP−ドデカン有機溶媒の一部を水蒸
気蒸留することによってドデカンを分留し、回収したド
デカンの必要量を希釈剤洗浄工程へリサイクルする。ま
た残りの溶媒を混合して抽出工程へリサイクルする。こ
れにより系から発生する廃溶媒量を極力少なくすること
ができる。TECHNICAL FIELD The present invention relates to a method for recycling an organic solvent in reprocessing a spent fuel by a solvent extraction method. Dodecane is fractionally distilled by steam-distilling a part of the TBP-dodecane organic solvent used in the reprocessing step, and the necessary amount of the recovered dodecane is recycled to the diluent washing step. The remaining solvent is mixed and recycled to the extraction process. This makes it possible to minimize the amount of waste solvent generated from the system.
［従来の技術］ 核燃料の再処理は、原子炉で使用した核燃料から核分裂
生成物を除去し、ウランやプルトニウム等の核分裂性物
質を分離して再び使用できるように処理することであ
る。再処理の方法にはいろいろあるが、現在最も広く用
いられているのは溶媒抽出法である。[Prior Art] Reprocessing of nuclear fuel is to remove fission products from nuclear fuel used in a nuclear reactor, separate fissionable materials such as uranium and plutonium, and treat them so that they can be reused. Although there are various reprocessing methods, the solvent extraction method is currently the most widely used.
従来の溶媒抽出法の一例を第６図に示す。抽出・洗浄工
程10への供給液（フィード）は使用済燃料の溶液であ
り、核分裂性物質（ＵやPu等）及び核分裂生成物は硝酸
溶液として存在する。この溶液を水に不溶なある種の有
機溶媒に接触させると、水層の核分裂性物質は有機層中
に抽出され核分裂生成物は水溶液中に残る。このことを
利用して分離が行われる。溶媒としては、TBP（トリブ
チルリン酸）が用いられるが、TBPを単独で用いると核
分裂性物質の抽出が進むに従って臨界安全性上の問題等
が生じるため、それ自身は抽出能を持たないドデカンを
希釈剤として用いる。一般的な溶媒の組成は30％TBP−7
0％ドデカンである。抽出・洗浄工程10で発生する水溶
液中には微量のTBPが溶解しているため、希釈剤洗浄工
程12において供給した100％ドデカンで洗浄する。水溶
液は高レベル廃液として蒸発缶へ送る。抽出・洗浄工程
10で有機層を硝酸（スクラブ）で洗浄し、逆抽出工程14
に送る。逆抽出工程14では有機層から核分裂性物質を水
層に逆抽出する。得られたプロダクト（水層）は精製工
程に送られる。逆抽出工程14から発生する有機溶媒は溶
媒洗浄工程16で洗浄した後、受槽18に送る。従って希釈
剤洗浄工程12で使用したドデカンと抽出・洗浄工程10で
使用した30％TBPとが同じ受槽18に溜まり混合すること
になる。そしてこの使用済有機溶媒は調整工程20に送ら
れ、そこで新たなTBPを添加し、30％TBP−70％ドデカン
に濃度調整して抽出・洗浄工程10に供給し再利用する。
調整工程20で生じる余分の溶媒は廃溶媒として系外に排
出する。An example of the conventional solvent extraction method is shown in FIG. A supply liquid (feed) to the extraction / washing step 10 is a solution of spent fuel, and fissionable substances (U, Pu, etc.) and fission products exist as nitric acid solution. When this solution is contacted with a certain organic solvent insoluble in water, the fissionable material in the water layer is extracted into the organic layer, and the fission products remain in the aqueous solution. Separation is performed by utilizing this fact. TBP (tributyl phosphate) is used as the solvent, but if TBP is used alone, problems such as criticality safety will occur as the extraction of fissile materials progresses. Used as a diluent. Typical solvent composition is 30% TBP-7
It is 0% dodecane. Since a trace amount of TBP is dissolved in the aqueous solution generated in the extraction / washing step 10, it is washed with 100% dodecane supplied in the diluent washing step 12. The aqueous solution is sent to the evaporator as high-level waste liquid. Extraction / washing process
The organic layer is washed with nitric acid (scrub) at 10 and back-extracted 14
Send to. In the back extraction step 14, the fissile material is back extracted from the organic layer into the aqueous layer. The obtained product (aqueous layer) is sent to the refining process. The organic solvent generated from the back extraction step 14 is washed in the solvent washing step 16 and then sent to the receiving tank 18. Therefore, the dodecane used in the diluent washing step 12 and the 30% TBP used in the extraction / washing step 10 will be collected and mixed in the same receiving tank 18. Then, the used organic solvent is sent to the adjusting step 20, where new TBP is added, the concentration is adjusted to 30% TBP-70% dodecane, and the organic solvent is supplied to the extracting / washing step 10 for reuse.
The excess solvent generated in the adjusting step 20 is discharged to the outside of the system as a waste solvent.
［発明が解決しようとする課題］ このように従来技術では使用済有機溶媒の再利用にあた
って、希釈剤洗浄工程12で供給したドデカンによってTB
Pが希釈されるため、調整工程20においてTBPを加える必
要がある。これらドデカンとTBPとは常に外部から系内
に供給し続ける必要がある。[Problems to be Solved by the Invention] As described above, in the prior art, when reusing a used organic solvent, TB was recovered by the dodecane supplied in the diluent washing step 12.
Since P is diluted, it is necessary to add TBP in the preparation step 20. These dodecane and TBP must always be continuously supplied to the system from the outside.
そのための系のホールドアップを越えないように、濃度
調整のため添加したTBP量と希釈剤洗浄のために添加し
たドデカン量の和に相当する量を廃溶媒として常に系外
に排出しなければならない。この廃溶媒発生量は運転時
間の経過とともに増加するため、溶媒抽出法における核
燃料再処理の大きな問題となっている。Therefore, the amount equivalent to the sum of the amount of TBP added for adjusting the concentration and the amount of dodecane added for washing the diluent must always be discharged out of the system as a waste solvent so as not to exceed the hold-up of the system. . The amount of waste solvent generated increases with the lapse of operating time, which is a major problem in nuclear fuel reprocessing in the solvent extraction method.
本発明の目的は、上記のような従来技術の欠点を解消
し、系から発生する廃溶媒量を極力少なくすることがで
き、且つ従来の設備を有効に利用でき、それに追加する
設備も小規模なもので済むようにした核燃料再処理にお
ける溶媒リサイクル方法を提供することにある。The object of the present invention is to eliminate the drawbacks of the prior art as described above, to reduce the amount of waste solvent generated from the system as much as possible, and to effectively use the conventional equipment, and the equipment to be added to it is small. It is to provide a method for recycling a solvent in a nuclear fuel reprocessing, which can be achieved by using a simple method.
［課題を解決するための手段］ 本発明は従来の溶媒抽出法による核燃料再処理におい
て、その工程の末端に水蒸気蒸留によるドデカン回収工
程を付設して溶媒のリサイクルを行うように構成したも
のである。[Means for Solving the Problems] The present invention is configured such that in the nuclear fuel reprocessing by the conventional solvent extraction method, a dodecane recovery process by steam distillation is additionally provided at the end of the process to recycle the solvent. .
即ち本発明は、使用済燃料の溶液をTBP−ドデカン有機
溶媒に接触させて核分裂性物質を抽出する抽出工程と、
該抽出工程から発生する水溶液にドデカンを接触させて
該水溶液中のTBPを除去する希釈剤洗浄工程と、前記抽
出工程の有機層から核分裂性物質を逆抽出する逆抽出工
程と、該逆抽出工程から発生する有機溶媒を洗浄する溶
媒洗浄工程とを有する核燃料再処理を前提としている。
そして前記の目的を達成するため本発明では、前記抽出
工程から発生する使用済有機溶媒の一部を水蒸気蒸留す
ることによりドデカンを分留し、前記希釈剤洗浄工程で
必要な量の回収ドデカンを前記希釈剤洗浄工程にリサイ
クルすると共に、残りの有機溶媒を混合して抽出工程に
リサイクルするように構成している。That is, the present invention, an extraction step of contacting the solution of the spent fuel with TBP-dodecane organic solvent to extract the fissile material,
A diluent washing step of contacting dodecane with the aqueous solution generated from the extraction step to remove TBP in the aqueous solution, a back-extraction step of back-extracting the fissile material from the organic layer of the extraction step, and the back-extraction step It is premised on the nuclear fuel reprocessing having a solvent washing step of washing the organic solvent generated from.
And in the present invention in order to achieve the above-mentioned object, the dodecane is fractionally distilled by steam-distilling a part of the used organic solvent generated from the extraction step, and a necessary amount of recovered dodecane is obtained in the diluent washing step. In addition to being recycled to the diluent washing step, the remaining organic solvent is mixed and recycled to the extraction step.
抽出工程にリサイクルする溶媒は、一般には30％TBP−7
0％ドデカンの混合溶媒である。The solvent used in the extraction process is generally 30% TBP-7.
It is a mixed solvent of 0% dodecane.
［作用］ 水蒸気蒸留によるドデカン分留は他の方法（減圧蒸留法
や液々抽出法）に比べて分離性並びに操作性の面で優れ
ている。そして種々の試験結果によれば、回収ドデカン
はほぼ完全にTBPから分離され、希釈剤洗浄用として十
分利用可能である。[Operation] Dodecane fractionation by steam distillation is superior to other methods (vacuum distillation method and liquid extraction method) in terms of separability and operability. According to various test results, the recovered dodecane is almost completely separated from TBP and can be sufficiently used as a diluent wash.
水蒸気蒸留法によって回収したドデカンは一定量のみ希
釈剤洗浄工程にリサイクルし、残液は再びTBPと混合し
て抽出工程へリサイクルする。従ってTBP濃度はドデカ
ンのリサイクル量によって自動的に決まる。ドデカンの
リサイクル量はTBPを希釈した分であるため、リサイク
ルするTBP濃度は一定に保たれる。Only a certain amount of dodecane recovered by the steam distillation method is recycled to the diluent washing step, and the residual liquid is mixed with TBP again and recycled to the extraction step. Therefore, the TBP concentration is automatically determined by the recycled amount of dodecane. Since the amount of dodecane recycled is the amount of diluted TBP, the TBP concentration to be recycled is kept constant.
このようにして系から発生する廃溶媒量は極めて少なく
なり、有機溶媒の工程内でのほぼ完全なクローズド化が
実現できる。In this way, the amount of waste solvent generated from the system is extremely small, and almost complete closure of the organic solvent in the process can be realized.
［実施例］ 第１図は本発明に係る核燃料再処理における溶媒リサイ
クル方法の一実施例を示す説明図である。末端の水蒸気
蒸留工程以降を除けばその前段までは第６図に示す従来
技術と同様であってよい。つまり従来の設備の大部分を
そのまま利用できる。従って説明が重複するため、従来
工程と同じ部分についての記載は省略する。[Example] FIG. 1 is an explanatory view showing an example of a solvent recycling method in nuclear fuel reprocessing according to the present invention. The process up to the preceding stage may be the same as that of the conventional technique shown in FIG. That is, most of the conventional equipment can be used as is. Therefore, since the description is duplicated, the description of the same parts as those in the conventional process is omitted.
溶媒洗浄工程16から発生する使用済有機溶媒は一旦受槽
18に溜められる。この使用済有機溶媒は、希釈剤洗浄工
程12においてドデカン洗浄剤を供給した分だけTBP濃度
が30％よりも低くなっている。The used organic solvent generated from the solvent washing step 16 is temporarily received
Stored in 18. The TBP concentration of this used organic solvent is lower than 30% by the amount of the dodecane cleaning agent supplied in the diluent cleaning step 12.
受槽18中の使用済有機溶媒のうち、希釈剤洗浄工程12で
添加したドデカン量もしくはそれを僅かに上回る量に対
応した量の溶媒を水蒸気蒸留装置24へ供給する。この水
蒸気蒸留装置24では有機溶媒中に水蒸気を通じながら蒸
留を行う。これによってドデカンのみをTBPからほぼ完
全に分留できる。TBPを水蒸気蒸留装置24の下部から取
り出し、受槽18の使用済有機溶媒とTBP受槽26で合流さ
せる。一方回収したドデカンはドデカン受槽28で凝縮水
を分離した後、希釈剤洗浄工程12で必要な量のみをリサ
イクルする。更に余分に残っているドデカンについては
TBP受槽26に送り、他の有機溶媒と混合し、それを抽出
・洗浄工程10に抽出剤としてリサイクルする。Of the used organic solvent in the receiving tank 18, an amount of the solvent corresponding to the amount of dodecane added in the diluent washing step 12 or an amount slightly exceeding it is supplied to the steam distillation device 24. In this steam distillation apparatus 24, distillation is performed while passing steam through an organic solvent. This makes it possible to fractionate only dodecane from TBP almost completely. The TBP is taken out from the lower part of the steam distillation device 24 and merged with the used organic solvent in the receiving tank 18 in the TBP receiving tank 26. On the other hand, for the collected dodecane, after condensing water in the dodecane receiving tank 28, only the necessary amount is recycled in the diluent washing step 12. For the extra dodecane remaining
It is sent to the TBP receiving tank 26, mixed with another organic solvent, and recycled in the extraction / washing step 10 as an extractant.
なおTBPの分解物であるDBPやMBPは前工程の溶媒洗浄工
程16で除去されており、水蒸気蒸留によって新たに発生
することはない。従って残液のTBP濃度はドデカンのリ
サイクル量によって自動的に決定され、このドデカン量
はTBPを希釈した分であるためリサイクルするTBP濃度は
一定（この場合30％）に保たれる。DBP and MBP, which are decomposition products of TBP, have been removed in the solvent washing step 16 in the previous step, and are not newly generated by steam distillation. Therefore, the TBP concentration of the residual liquid is automatically determined by the recycled amount of dodecane, and since this amount of dodecane is the diluted amount of TBP, the recycled TBP concentration is kept constant (30% in this case).
次に本発明においてドデカン回収を行う水蒸気蒸留につ
いて行った基礎試験の結果を説明する。水蒸気蒸留法は
水蒸気を使用するために、層分離および水の処理が必要
になるが、操作温度を100℃程度に限定できる利点があ
る。そこで水蒸気共存下での蒸留試験により水蒸気と留
出液組成との相関を調べた。水蒸気量は6,11,20／分
で行った。各条件における試験結果を第２図〜第４図並
びに第１表〜第３表に示す。また水蒸気量による留出量
の変化を第５図に示す。Next, the results of a basic test conducted on steam distillation for recovering dodecane in the present invention will be described. Since the steam distillation method uses steam, layer separation and water treatment are required, but there is an advantage that the operating temperature can be limited to about 100 ° C. Therefore, the correlation between steam and distillate composition was investigated by a distillation test in the presence of steam. The amount of water vapor was 6,11,20 / min. The test results under each condition are shown in FIGS. 2 to 4 and Tables 1 to 3. Fig. 5 shows the change in the amount of distillate depending on the amount of water vapor.
以上の基礎試験において次のような現象が見出された。 The following phenomena were found in the above basic tests.
共沸現象はない。 There is no azeotropic phenomenon.
ｎ−ブチルアルコールとドデカンの分離、及びブチ
ルリン酸類からのこれらの分離は可能である。Separation of n-butyl alcohol and dodecane, and their separation from butyl phosphates is possible.
添加する水蒸気量に比例してドデカンの留出速度は
増加する。The rate of distillation of dodecane increases in proportion to the amount of water vapor added.
TBP等ブチルリン酸は留出しない。 Butylphosphoric acid such as TBP is not distilled.
ブチルリン酸の分解は認められない。 No decomposition of butyl phosphate is observed.
水とドデカンの層分離は容易である。 The layers of water and dodecane are easy to separate.
ドデカンからブチルリン酸を除去する方法としては、水
蒸気蒸留の他、減圧蒸留法や液々抽出法等がある。これ
らの分離方法についても検討を行ったが、液々抽出法で
はブチルリン酸類を完全に分離することができなかっ
た。減圧蒸留法では分離性については問題ないと判断さ
れるが、操作の複雑さやブチルリン酸の熱分解等を伴
う。これに対して水蒸気蒸留法は留出液の水層分離を要
するものの分離性並びに操作性などから最も有利である
ことが判った。As a method for removing butylphosphoric acid from dodecane, there are a vacuum distillation method, a liquid extraction method and the like in addition to steam distillation. The separation method was also investigated, but butyl phosphates could not be completely separated by the liquid-liquid extraction method. Although it is judged that there is no problem in separability by the vacuum distillation method, it involves complicated operations and thermal decomposition of butyl phosphoric acid. On the other hand, the steam distillation method has been found to be most advantageous in terms of separability and operability although it requires separation of the distillate in the aqueous layer.
［発明の効果］ 本発明は上記のように溶媒抽出法による核燃料再処理に
おいて水蒸気蒸留によってドデカンを分留するように構
成したから、ドデカンをほぼ完全にTBPから分離するこ
とができ希釈剤洗浄用として十分利用可能である。この
回収ドデカンを希釈剤洗浄工程にリサイクルすること
で、残りの有機溶媒のTBP濃度も自動的に当初の濃度に
調整され、それを抽出工程にリサイクルするため、系か
ら発生する廃溶媒量を極力少なくでき、系内で有機溶媒
のほぼ完全なクローズド化を図ることができる。[Advantages of the Invention] Since the present invention is configured to fractionate dodecane by steam distillation in the nuclear fuel reprocessing by the solvent extraction method as described above, it is possible to almost completely separate dodecane from TBP for cleaning the diluent. Is fully available as. By recycling this recovered dodecane to the diluent washing process, the TBP concentration of the remaining organic solvent is automatically adjusted to the initial concentration, and it is recycled to the extraction process, so the amount of waste solvent generated from the system is minimized. The amount can be reduced, and the organic solvent can be almost completely closed in the system.
また水蒸気蒸留装置の処理能力についても、すべての使
用済有機溶媒を対象とするのではなく、リサイクルに必
要なドデカン量を確保できればよいため小規模な設備で
よく、従来装置の大部分を利用できることも相俟て設備
費用は比較的少なくて済む。ドデカン及びTBPを新たに
添加する必要がほとんどないし、廃溶媒発生量が非常に
少ないため運転費用も低減できる。また水蒸気蒸留のた
め操作性の点でも良好である。Regarding the processing capacity of the steam distillation device, it is not necessary to target all used organic solvents, but it is sufficient to secure the amount of dodecane necessary for recycling, so a small-scale facility is sufficient, and most of the conventional devices can be used. Combined with this, the equipment cost is relatively low. There is almost no need to newly add dodecane and TBP, and the amount of waste solvent generated is extremely small, so operating costs can be reduced. Also, since it is steam distillation, the operability is also good.
本発明方法の採用により、希釈剤洗浄に使用するドデカ
ン量を増加させても廃溶媒発生量が増大しないから、よ
り効果的な希釈剤洗浄を行うことが可能となる。特に希
釈剤洗浄工程に遠心抽出機を採用する場合、インベント
リーが少ないため従来方法よりも大きなドデカン供給量
を必要とするが、本発明方法ではそのリサイクルが可能
であり廃溶媒発生量が極めて少なくなるため、遠心抽出
機による希釈剤洗浄工程には特に有効である。By adopting the method of the present invention, the amount of waste solvent generated does not increase even if the amount of dodecane used for cleaning the diluent is increased, so that more effective cleaning of the diluent can be performed. Especially when a centrifugal extractor is used in the diluent washing step, a large inventory of dodecane is required because of a small inventory, but the method of the present invention can recycle the waste solvent and the amount of waste solvent generated is extremely small. Therefore, it is particularly effective for a diluent washing step using a centrifugal extractor.
第１図は本発明に係る核燃料再処理における溶媒リサイ
クル方法の一実施例を示す説明図、第２図は水蒸気蒸留
法による水蒸気量６／分での留出曲線図、第３図は水
蒸気量11／分での留出曲線図、第４図は水蒸気量20
／分での留出曲線図、第５図は留出量に及ぼす水蒸気量
の影響を示すグラフである。また第６図は従来技術の一
例を示す説明図である。 10……抽出・洗浄工程、12……希釈剤洗浄工程、14……
逆抽出工程、16……溶媒洗浄工程、18……受槽、20……
調整工程、24……水蒸気蒸留装置、26……TBP受槽、28
……ドデカン受槽。FIG. 1 is an explanatory diagram showing an embodiment of a solvent recycling method in nuclear fuel reprocessing according to the present invention, FIG. 2 is a distillation curve diagram at a steam amount of 6 / min by a steam distillation method, and FIG. 3 is a steam amount. Distillation curve diagram at 11 / min, Fig. 4 shows water vapor amount of 20
Fig. 5 is a graph showing the distilling curve of the amount of steam per minute. Further, FIG. 6 is an explanatory diagram showing an example of a conventional technique. 10 …… Extraction / washing process, 12 …… Diluent washing process, 14 ……
Back extraction process, 16 …… Solvent washing process, 18 …… Receiving tank, 20 ……
Adjustment process, 24 …… Steam distillation device, 26 …… TBP receiving tank, 28
…… Dodecane receiving tank.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小沢 正基 茨城県那珂郡東海村大字村松４番地33 動 力炉・核燃料開発事業団東海事業所内 (56)参考文献 特開 昭62−180296（ＪＰ，Ａ) 特開 昭63−31504（ＪＰ，Ａ) 特開 昭63−180296（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Ozawa 4-4 Muramatsu, Tokai-mura, Naka-gun, Ibaraki Prefecture Inside the Tokai Works, Reactor and Nuclear Fuel Development Corporation (56) Reference JP 62-180296 (JP, A) JP-A-63-31504 (JP, A) JP-A-63-180296 (JP, A)
Claims (2)
媒に接触させて核分裂性物質を抽出する抽出工程と、該
抽出工程から発生する水溶液にドデカンを接触させて該
水溶液中のTBPを除去する希釈剤洗浄工程と、前記抽出
工程の有機層から核分裂性物質を逆抽出する逆抽出工程
と、該逆抽出工程から発生する有機溶媒を洗浄する溶媒
洗浄工程とを有する核燃料再処理において、前記抽出工
程から発生する使用済有機溶媒の一部を水蒸気蒸留する
ことによりドデカンを分留し、前記希釈剤洗浄工程で必
要な量の回収ドデカンの前記希釈剤洗浄工程にリサイク
ルすると共に、残りの有機溶媒を混合して抽出工程にリ
サイクルすることを特徴とする核燃料再処理における溶
媒リサイクル方法。1. An extraction step of contacting a spent fuel solution with a TBP-dodecane organic solvent to extract a fissionable material, and an aqueous solution generated from the extraction step is contacted with dodecane to remove TBP from the aqueous solution. In the nuclear fuel reprocessing, which comprises a diluent washing step to do, a back extraction step of back extracting the fissile material from the organic layer of the extraction step, and a solvent washing step of washing the organic solvent generated from the back extraction step, Dodecane is fractionally distilled by steam-distilling a part of the used organic solvent generated from the extraction step, and the amount of recovered dodecane necessary for the diluent washing step is recycled to the diluent washing step, while the remaining organic solvent is removed. A solvent recycling method in nuclear fuel reprocessing, characterized in that a solvent is mixed and recycled in an extraction step.
TBP−70％ドデカンである請求項１記載の方法。2. Organic solvent recycled to the extraction step is 30%
The method of claim 1 which is TBP-70% dodecane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13834989A JPH07109438B2 (en) | 1989-05-31 | 1989-05-31 | Solvent recycling method in nuclear fuel reprocessing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13834989A JPH07109438B2 (en) | 1989-05-31 | 1989-05-31 | Solvent recycling method in nuclear fuel reprocessing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH032694A JPH032694A (en) | 1991-01-09 |
| JPH07109438B2 true JPH07109438B2 (en) | 1995-11-22 |
Family
ID=15219850
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13834989A Expired - Fee Related JPH07109438B2 (en) | 1989-05-31 | 1989-05-31 | Solvent recycling method in nuclear fuel reprocessing |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07109438B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100521748C (en) | 2001-04-12 | 2009-07-29 | 索尼公司 | Signal processing device, storage rack and connecting device |
-
1989
- 1989-05-31 JP JP13834989A patent/JPH07109438B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH032694A (en) | 1991-01-09 |
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