JPH0242397A - Cleaning method for sludge in fuel reprocessing - Google Patents
Cleaning method for sludge in fuel reprocessingInfo
- Publication number
- JPH0242397A JPH0242397A JP19213588A JP19213588A JPH0242397A JP H0242397 A JPH0242397 A JP H0242397A JP 19213588 A JP19213588 A JP 19213588A JP 19213588 A JP19213588 A JP 19213588A JP H0242397 A JPH0242397 A JP H0242397A
- Authority
- JP
- Japan
- Prior art keywords
- sludge
- ruthenium
- plutonium
- cleaning
- 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.)
- Pending
Links
- 238000004140 cleaning Methods 0.000 title claims abstract description 55
- 239000010802 sludge Substances 0.000 title claims abstract description 44
- 238000000034 method Methods 0.000 title claims abstract description 32
- 239000000446 fuel Substances 0.000 title claims abstract description 12
- 238000012958 reprocessing Methods 0.000 title claims description 10
- 230000001590 oxidative effect Effects 0.000 claims abstract description 21
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 15
- 230000002378 acidificating effect Effects 0.000 claims description 13
- 239000002915 spent fuel radioactive waste Substances 0.000 claims description 9
- 238000005352 clarification Methods 0.000 claims description 8
- 229910052707 ruthenium Inorganic materials 0.000 abstract description 28
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 abstract description 26
- 229910052778 Plutonium Inorganic materials 0.000 abstract description 25
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 abstract description 25
- 239000007788 liquid Substances 0.000 abstract description 17
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 abstract description 17
- 239000003960 organic solvent Substances 0.000 abstract description 13
- 150000002500 ions Chemical class 0.000 abstract description 9
- 239000006096 absorbing agent Substances 0.000 abstract description 8
- 229910052770 Uranium Inorganic materials 0.000 abstract description 6
- 239000007791 liquid phase Substances 0.000 abstract description 6
- 239000007800 oxidant agent Substances 0.000 abstract description 6
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 abstract description 6
- 239000003957 anion exchange resin Substances 0.000 abstract description 3
- 239000011521 glass Substances 0.000 abstract description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 3
- 239000002253 acid Substances 0.000 abstract 2
- HSJPMRKMPBAUAU-UHFFFAOYSA-N cerium(3+);trinitrate Chemical group [Ce+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O HSJPMRKMPBAUAU-UHFFFAOYSA-N 0.000 abstract 2
- 230000008016 vaporization Effects 0.000 abstract 1
- 229910052684 Cerium Inorganic materials 0.000 description 8
- 238000004017 vitrification Methods 0.000 description 8
- 239000012071 phase Substances 0.000 description 6
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 5
- 239000010419 fine particle Substances 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 229910001927 ruthenium tetroxide Inorganic materials 0.000 description 4
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 3
- -1 cerium ion Chemical class 0.000 description 3
- 239000003456 ion exchange resin Substances 0.000 description 3
- 229920003303 ion-exchange polymer Polymers 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002927 high level radioactive waste Substances 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 230000008929 regeneration Effects 0.000 description 2
- 238000011069 regeneration method Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 229910001093 Zr alloy Inorganic materials 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- SHZGCJCMOBCMKK-KGJVWPDLSA-N beta-L-fucose Chemical compound C[C@@H]1O[C@H](O)[C@@H](O)[C@H](O)[C@@H]1O SHZGCJCMOBCMKK-KGJVWPDLSA-N 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- OSUPRVCFDQWKQN-UHFFFAOYSA-N cerium;nitric acid Chemical compound [Ce].O[N+]([O-])=O.O[N+]([O-])=O.O[N+]([O-])=O.O[N+]([O-])=O.O[N+]([O-])=O.O[N+]([O-])=O OSUPRVCFDQWKQN-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000004992 fission Effects 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000010309 melting process Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 150000003303 ruthenium Chemical class 0.000 description 1
- 229910001925 ruthenium oxide Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔発明の目的〕
（産業上の利用分野）
本発明は使用済み燃料の再処理施設において、使用済み
燃料を溶解したのち清澄工程で発生する不溶解性残渣（
以下スラッジと称す）を洗浄する燃料再処理におけるス
ラッジの洗浄方法に関する。[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention is a spent fuel reprocessing facility, in which insoluble residue (
The present invention relates to a method for cleaning sludge in fuel reprocessing (hereinafter referred to as sludge).
（従来の技術）
使用済み燃料再処理施設においては、使用済み燃料を解
体・切断後、硝酸を用いて溶解する。この場合、少量の
有用核種（とくにプルトニウム）。(Prior art) In a spent fuel reprocessing facility, spent fuel is dismantled and cut, and then dissolved using nitric acid. In this case, a small amount of useful nuclides (especially plutonium).
核分裂生成物の一部（例えばルテニウム、パラジウム、
モリブデンなど）およびジルカロイ燃料被覆管の切屑が
不溶解性残渣（スラッジ）として溶解液中に残る。ウラ
ン、プルトニウムを有機溶媒で抽出する前にあらかじめ
微粒子状のスラッジを除去しておく必要がある。このス
ラッジを固液分離するための清澄工程には、パルスフィ
ルタまたは遠心清澄機が用いられている。パルスフィル
タまたは遠心清澄機で除去したスラッジは、付着してい
るウラン、プルトニウムを極力回収するため硝酸を洗浄
液として洗浄後、安全に長期にわたり貯蔵・処分するた
めガラス固化される。Some of the fission products (e.g. ruthenium, palladium,
molybdenum, etc.) and chips from the Zircaloy fuel cladding remain in the solution as insoluble residue (sludge). Before extracting uranium and plutonium with an organic solvent, it is necessary to remove particulate sludge. A pulse filter or a centrifugal clarifier is used in the clarification process to separate solid and liquid from this sludge. The sludge removed by a pulse filter or centrifugal clarifier is washed with nitric acid as a cleaning solution to recover as much of the attached uranium and plutonium as possible, and then vitrified for safe long-term storage and disposal.
ところで、燃料の燃焼度を高めると、特に高速増殖炉（
以下ＦＢＲと称す）では、使用済み燃料中の難溶解性プ
ルトニウム量が次第に増加する。By the way, increasing the burnup of the fuel is especially important for fast breeder reactors (
(hereinafter referred to as FBR), the amount of poorly soluble plutonium in the spent fuel gradually increases.
この難溶解性プルトニウム微粒子は清澄工程で除去した
スラッジ中に相当量含まれており、硝酸による洗浄では
溶解・回収することが困難であり、有用核種の損失、廃
棄物対策などの観点から好ましくない事態が生じる。ま
たスラッジの主要成分であるルテニウムの量も増加する
。このルテニウムは高レベル廃液中ないしはスラッジの
ガラス固化工程で高温のため揮発することと、その長半
減期のため廃棄物処理上問題が多い成分である。A considerable amount of these poorly soluble plutonium particles are contained in the sludge removed during the clarification process, and it is difficult to dissolve and recover them by cleaning with nitric acid, which is undesirable from the standpoint of loss of useful nuclides and waste management. A situation arises. Also, the amount of ruthenium, which is the main component of sludge, increases. This ruthenium is a component that causes many problems in waste treatment because it volatilizes due to the high temperature during the vitrification process of high-level waste liquids or sludge, and because of its long half-life.
（発明が解決しようとする課題）
従来、使用済み燃料の再処理施設において、清澄工程で
除去したスラッジは硝酸で洗浄された後。(Problems to be Solved by the Invention) Conventionally, in spent fuel reprocessing facilities, the sludge removed in the clarification process is washed with nitric acid.
高レベル廃液のガラス固化工程でガラス固化される。It is vitrified in the vitrification process of high-level waste liquid.
しかしながら、この従来からの洗浄方法ではスラッジ中
に含まれる多量のルテニウムが高温のため気相中に揮発
、移行して放射性汚染をひきおこす可能性が高い。この
ため、ルテニウムばあらがしめスラッジ中から除去して
おくことが望ましい。However, in this conventional cleaning method, there is a high possibility that a large amount of ruthenium contained in the sludge will volatilize and migrate into the gas phase due to the high temperature, causing radioactive contamination. For this reason, it is desirable to remove ruthenium from the sludge.
このルテニウムの問題は、燃料の燃焼度が上がるにつれ
ルテニウムの割合いが増大するため大きくなる。This problem with ruthenium increases as the burn-up of the fuel increases because the proportion of ruthenium increases.
また燃料の燃焼度が上がるにつれ、とくにＦＢＲでは、
溶解工程で溶けにくい難溶解性プルトニウムが増大する
。この難溶解性プルトニウムはスラッジとともにガラス
固化工程に送られガラス固化される。プルトニウムの半
減期は非常に長く（Ｐｕ −２３９：約２０，０００年
）、かつ化学的毒性の強い核種である１本来プルトニウ
ムは燃料として利用すべき物質であり、ガラス固化工程
へ送らず１回収すべきものなのである。Also, as fuel burnup increases, especially in FBR,
During the melting process, the amount of plutonium that is difficult to dissolve increases. This hardly soluble plutonium is sent to the vitrification process together with the sludge and is vitrified. Plutonium has a very long half-life (Pu-239: approximately 20,000 years) and is a highly chemically toxic nuclide.1 Originally, plutonium was a substance that should be used as fuel, so it was recovered without being sent to the vitrification process. It is something that should be done.
従来の硝酸によるスラッジの洗浄方法では、ルテニウム
の除去、難溶解性プルトニウムの回収は全くできない。Conventional sludge cleaning methods using nitric acid cannot remove ruthenium or recover hardly soluble plutonium.
本発明は、以上の事情に鑑みてなされたものであり、高
燃焼度の使用済み燃料、特にＦＢＨの再処理施設におい
て、清澄工程で除去したスラッジ中に含まれる有用核種
の難溶解性プルトニウムを溶解・回収するとともに同じ
くガラス同化妨害核種のルテニウムを揮発・除去するこ
とができる燃料再処理におけるスラッジ洗浄方法を提供
することにある。The present invention has been made in view of the above circumstances, and is a method for removing refractory plutonium, a useful nuclide, contained in the sludge removed in the clarification process at high burnup spent fuel, particularly in FBH reprocessing facilities. The object of the present invention is to provide a method for cleaning sludge in fuel reprocessing, which can dissolve and recover ruthenium and also volatilize and remove ruthenium, a nuclide that interferes with glass assimilation.
（課題を解決するための手段）
本発明は使用済み燃料を解体、切断し、硝酸で溶解処理
したのち、清澄工程で除去したスラッジを強酸化性酸性
洗浄液で洗浄処理することを特徴とする。(Means for Solving the Problems) The present invention is characterized in that spent fuel is dismantled, cut, and dissolved in nitric acid, and then the sludge removed in the clarification step is cleaned with a strongly oxidizing acidic cleaning solution.
（作用）
酸化性酸性洗浄液に含まれる酸化剤の酸化作用によって
スラッジ中の難溶解性の酸化プルトニウム微粒子を洗浄
液中に溶出させる。洗浄液中に溶出したプルトニウムは
イオン交換樹脂で洗浄液中から吸着・回収する。また、
ルテニウムも酸化性酸性洗浄液中の酸化剤の酸化作用に
よって４酸化ルテニウムに酸化し、気相中に揮発させる
。揮発したルテニウムは凝縮器で水分とルテニウムの一
部を回収するとともに有機溶媒の吸収器で２酸化ルテニ
ウムに還元して回収する。(Function) The oxidizing action of the oxidizing agent contained in the oxidizing acidic cleaning solution causes the hardly soluble plutonium oxide fine particles in the sludge to be eluted into the cleaning solution. Plutonium eluted into the cleaning solution is adsorbed and recovered from the cleaning solution using an ion exchange resin. Also,
Ruthenium is also oxidized to ruthenium tetraoxide by the oxidizing action of the oxidizing agent in the oxidizing acidic cleaning solution, and is volatilized into the gas phase. The volatilized ruthenium is recovered by recovering water and part of the ruthenium in a condenser, and is reduced to ruthenium dioxide in an organic solvent absorber.
酸化性酸性洗浄液はスラッジを洗浄することによってそ
の酸化力を喪失するが、この洗浄液の酸化力は電解反応
により再生させることができる。Although the oxidizing acidic cleaning liquid loses its oxidizing power by cleaning the sludge, the oxidizing power of this cleaning liquid can be regenerated by electrolytic reaction.
このようにしてスラッジ中から有用核種を回収するとと
もに、ガラス固化工程の妨害核種を除去する。In this way, useful nuclides are recovered from the sludge, and nuclides that interfere with the vitrification process are removed.
（実施例）
本発明に係る燃料再処理におけるスラッジの洗浄方法の
一実施例を図を参照しながら説明する。(Example) An example of the sludge cleaning method in fuel reprocessing according to the present invention will be described with reference to the drawings.
まず、使用済み燃料を解体、切断し硝酸で溶解し。First, the spent fuel is dismantled, cut up and dissolved in nitric acid.
清澄工程で除去したスラッジを洗浄器１に受入れる。洗
浄器１の構造としては撹拌槽洗浄、遠心洗浄、スプレー
洗浄などが使用されるが、その構造は特に限定しない、
酸化性酸性洗浄液としては酸化剤として硝酸第２セリウ
ム（セリウム４価イオン）を、酸性液として硝酸を用い
る。セリウム濃度は０．０５ｍｏｌ＃！から０．８ｍｏ
ｌ／ｆｆｉの範囲とする。硝酸濃度は０．５ｍｏ１／１
２から６ｍｏｌ＃Ｉの範囲が望ましい。洗浄液の温度は
室温から沸騰温度まで適用できるが、洗浄性からは高い
ほうが望ましい。The sludge removed in the clarification process is received in a washer 1. The structure of the cleaning device 1 includes stirring tank cleaning, centrifugal cleaning, spray cleaning, etc., but the structure is not particularly limited.
As the oxidizing acidic cleaning liquid, ceric nitrate (tetravalent cerium ion) is used as the oxidizing agent, and nitric acid is used as the acidic liquid. Cerium concentration is 0.05mol#! from 0.8mo
The range is l/ffi. Nitric acid concentration is 0.5mol1/1
A range of 2 to 6 mol #I is desirable. The temperature of the cleaning liquid can range from room temperature to boiling temperature, but higher temperatures are desirable from the viewpoint of cleaning performance.
上記酸化性酸性洗浄液によってスラッジを洗浄した後、
ガラス固化工程に移送し、ガラス固化する。ガラス固化
したスラッジは貯蔵庫に貯蔵するか、または処分する。After cleaning the sludge with the above oxidizing acidic cleaning solution,
Transfer to vitrification process and vitrify. The vitrified sludge can be stored in storage or disposed of.
洗浄器１でスラッジを洗浄後の洗浄液はイオン交換器２
によってプルトニウムおよびウランを吸着回収する。イ
オン交換器２に充填されるイオン交換樹脂としては陰イ
オン交換樹脂を用いる。プルトニウム、ウランはセリウ
ムで酸化されて、６価イオンに変換されているため水和
効果により陰イオンに選択的に吸着される。以上の作用
により難溶解性のプルトニウムはスラッジから分離・回
収される。イオン交換器２の構造は回分式または連続カ
ラム式どちらでもかまわない。After washing the sludge with washer 1, the cleaning liquid is sent to ion exchanger 2.
plutonium and uranium are adsorbed and recovered. As the ion exchange resin filled in the ion exchanger 2, an anion exchange resin is used. Plutonium and uranium are oxidized with cerium and converted into hexavalent ions, so they are selectively adsorbed by anions due to the hydration effect. Due to the above action, the hardly soluble plutonium is separated and recovered from the sludge. The structure of the ion exchanger 2 may be either a batch type or a continuous column type.
スラッジを洗浄し、プルトニウム回収後の酸化性酸性洗
浄液は洗浄作用により酸化能力が低下ないしは喪失して
いる。すなわち、セリウム４価イオンはセリウム３価イ
オンに還元されている。このため、電解再生槽３におい
て陽極表面でセリウムは３価から４価イオンに酸化し、
再生される。The oxidizing acidic cleaning solution after cleaning the sludge and recovering plutonium has reduced or lost its oxidizing ability due to the cleaning action. That is, tetravalent cerium ions are reduced to trivalent cerium ions. Therefore, in the electrolytic regeneration tank 3, cerium is oxidized from trivalent to tetravalent ions on the anode surface.
will be played.
再生された酸化性酸性洗浄液は再び洗浄器１でスラッジ
の洗浄に用いられる。電極としては白金電極ないしは白
金被覆電極が望ましい。The regenerated oxidizing acidic cleaning liquid is used again in the cleaning device 1 to clean the sludge. The electrode is preferably a platinum electrode or a platinum-coated electrode.
洗浄器１で発生するオフガスは凝縮器４で水分を除去す
る６ルテニウムの一部は還元さ九２酸化ルテニウムとし
て凝縮器４で水とともに凝縮、回収される。脱水・乾燥
したオフガスは次に吸収器５に通される。吸収液には有
機溶媒を用いる。特に有機溶媒としては、炭素数が６か
ら１２程度のパラフィン系炭化水素が効率良く４酸化ル
テニウムを還元、吸収できる。これら有機溶媒により揮
発性４酸化ルテニウムは還元され２酸化ルテニウムの微
粒子として有機溶媒中にトラップされる。吸収器５の構
造としては回分式バブリング法、スプレィ式吸収法、充
填塔法などがあるが、特に限定しない。吸収液中に分散
している２酸化ルテニウムの微粒子は液相フィルタ６で
濾過、除去される。The off-gas generated in the washer 1 is removed in a condenser 4 to remove moisture. Part of the 6-ruthenium is reduced and condensed together with water in the condenser 4 as ruthenium 92 oxide and recovered. The dehydrated and dried off-gas is then passed through the absorber 5. An organic solvent is used for the absorption liquid. In particular, as an organic solvent, paraffinic hydrocarbons having about 6 to 12 carbon atoms can efficiently reduce and absorb ruthenium tetroxide. Volatile ruthenium tetroxide is reduced by these organic solvents and trapped in the organic solvent as fine particles of ruthenium dioxide. The structure of the absorber 5 includes a batch bubbling method, a spray absorption method, a packed column method, etc., but is not particularly limited. Fine particles of ruthenium dioxide dispersed in the absorption liquid are filtered and removed by a liquid phase filter 6.
ルテニウムを凝縮器４、吸収器５で除去した後のオフガ
スは吸収液の飛沫をデミスタ７で除去した後、放出する
。After ruthenium has been removed in the condenser 4 and absorber 5, the off-gas is discharged after the droplets of the absorption liquid are removed in the demister 7.
上記実施例では酸化性酸性洗浄液としてセリウム−硝酸
洗浄液について説明したが、酸化剤はプルトニウム、ル
テニウムより酸化電位が高くかつ複数のイオン価数を有
する元素ないしは分子であればセリウムにこだわるもの
ではない。例えばビスマス、マンガンなどでもかまわな
い。In the above embodiment, a cerium-nitric acid cleaning solution was described as the oxidizing acidic cleaning solution, but the oxidizing agent is not limited to cerium as long as it is an element or molecule that has a higher oxidation potential than plutonium or ruthenium and has multiple ionic valences. For example, bismuth, manganese, etc. may be used.
この実施例に係るスラッジの洗浄方法においては、セリ
ウム４価イオン−硝酸の酸化性酸性洗浄液の酸化力は従
来用いられてきた硝酸洗浄液の酸化力よりも非常に大き
いため、硝酸洗浄液で溶解することができなかった難溶
解性プルトニウムをＰｕＯ□（２−）イオンとして洗浄
液中に溶解する。また、ルテニウムも４酸化ルテニウム
に酸化し、気相中に揮発させることができる。In the sludge cleaning method according to this embodiment, the oxidizing power of the oxidizing acidic cleaning solution of cerium tetravalent ions and nitric acid is much greater than that of the conventionally used nitric acid cleaning solution, so the sludge cannot be dissolved in the nitric acid cleaning solution. The poorly soluble plutonium that cannot be dissolved is dissolved in the cleaning solution as PuO□(2-) ions. Furthermore, ruthenium can also be oxidized to ruthenium tetraoxide and volatilized into the gas phase.
Ｒｕ＋８Ｃｅ（４＋）＋４Ｈ，０＝Ｒｕ０４＋８０ｅ（
３＋）＋８Ｈ（”）この結果、難溶解性プルトニウムは
洗浄液中に移行する。洗浄液に移行した陰イオン性のプ
ルトニウムは陰イオン交換樹脂によって回収することが
できる。Ru+8Ce(4+)+4H,0=Ru04+80e(
3+)+8H('')As a result, the hardly soluble plutonium migrates into the cleaning solution.The anionic plutonium that migrates into the cleaning solution can be recovered by an anion exchange resin.
また、ガラス固化工程に持込みたくないスラッジ中のル
テニウムも酸化剤により揮発し、気相中に移行する。気
相中に移行した４酸化ルテニウムは水分を除去する凝縮
器４で一部還元し２酸化ルテニウムとして凝縮・回収さ
れる。凝縮器４を通過したルテニウムは次の有機溶媒を
用いたガス吸収器５で有機溶媒により還元され、２酸化
ルテニウム微粒子として有機溶媒中に回収される。二の
２酸化ルテニウム微粒子は、有機溶媒を液相フィルタ６
に通すことにより液相フィルタ６の表面上に除去・回収
することができる。Moreover, ruthenium in the sludge, which is not desired to be brought into the vitrification process, is also volatilized by the oxidizing agent and transferred into the gas phase. The ruthenium tetroxide that has migrated into the gas phase is partially reduced in a condenser 4 that removes moisture, and is condensed and recovered as ruthenium dioxide. The ruthenium that has passed through the condenser 4 is reduced by the next gas absorber 5 using an organic solvent, and is recovered in the organic solvent as ruthenium dioxide fine particles. The second ruthenium dioxide fine particles filter the organic solvent through the liquid phase filter 6.
It can be removed and collected on the surface of the liquid phase filter 6 by passing it through the liquid phase filter 6.
清澄工程で除去したスラッジに含まれる雅溶解性プルト
ニウムは効率良く回収されるとともに、ガラス固化処理
上除去したいルテニウムも分離される。The soluble plutonium contained in the sludge removed during the clarification process is efficiently recovered, and the ruthenium that should be removed during the vitrification process is also separated.
洗浄によってスラッジから洗浄液中に溶出したプルトニ
ウムとウランはイオン交換樹脂で回収される。Plutonium and uranium eluted from the sludge into the cleaning solution are recovered using an ion exchange resin.
洗浄によってスラッジから気相中に揮発したルテニウム
を凝縮器と有機溶媒によるガス吸収器で回収し、有機溶
媒中に移行した粒子状酸化ルテニウムをフィルタで除去
する。The ruthenium volatilized from the sludge into the gas phase by washing is recovered by a condenser and a gas absorber using an organic solvent, and the particulate ruthenium oxide that has migrated into the organic solvent is removed by a filter.
さらにスラッジを洗浄したことによって酸化機能が低下
した酸化性酸性洗浄液は電解槽で電解酸化反応によって
再生する。そのため、洗浄液の寿命は非常に長く、従来
の硝酸洗浄方法に比べていわゆる２次廃棄物量を減らす
ことができる。Furthermore, the oxidizing acidic cleaning solution whose oxidizing function has been degraded by cleaning the sludge is regenerated by an electrolytic oxidation reaction in an electrolytic cell. Therefore, the life of the cleaning liquid is very long, and the amount of so-called secondary waste can be reduced compared to the conventional nitric acid cleaning method.
本発明によればプルトニウムを高い効率で回収すること
ができるため、製品の歩留り、計量管理上の問題を解決
することができる。また、ルテニウムを洗浄工程で分離
・除去できるため、スラッジをガラス固化する場合ガラ
ス溶融炉の設計並びに操作条件が非常に容易になる。According to the present invention, plutonium can be recovered with high efficiency, so problems in product yield and measurement management can be solved. Furthermore, since ruthenium can be separated and removed in the cleaning process, the design and operating conditions of the glass melting furnace when vitrifying sludge are greatly simplified.
図は本発明に係る燃料再処理におけるスラッジの洗浄方
法の一実施例を示す流れ線図である。
１・・・洗浄器
２・・・イオン交換器
３・・・電解再生槽
４・・凝縮器
５・・・吸収器
６・・・液相フィルタ
７・・・デミスタThe figure is a flow chart showing an embodiment of the sludge cleaning method in fuel reprocessing according to the present invention. 1... Cleaner 2... Ion exchanger 3... Electrolytic regeneration tank 4... Condenser 5... Absorber 6... Liquid phase filter 7... Demister
Claims (1)
、清澄工程で除去したスラッジを強酸化性酸性洗浄液で
洗浄処理することを特徴とする燃料再処理におけるスラ
ッジの洗浄方法。A method for cleaning sludge in fuel reprocessing, which comprises dismantling and cutting spent fuel, dissolving it in nitric acid, and then cleaning the sludge removed in a clarification process with a strongly oxidizing acidic cleaning solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19213588A JPH0242397A (en) | 1988-08-02 | 1988-08-02 | Cleaning method for sludge in fuel reprocessing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19213588A JPH0242397A (en) | 1988-08-02 | 1988-08-02 | Cleaning method for sludge in fuel reprocessing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0242397A true JPH0242397A (en) | 1990-02-13 |
Family
ID=16286266
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19213588A Pending JPH0242397A (en) | 1988-08-02 | 1988-08-02 | Cleaning method for sludge in fuel reprocessing |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0242397A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014062737A (en) * | 2012-09-19 | 2014-04-10 | Mitsubishi Heavy Ind Ltd | Method and apparatus for detoxifying incineration ash containing radioactive cesium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS588505A (en) * | 1981-07-08 | 1983-01-18 | Toyobo Co Ltd | Semi-permeable composite membrane |
| JPS6125608A (en) * | 1984-07-14 | 1986-02-04 | Agency Of Ind Science & Technol | Separating film for water-soluble organic material and separation of water-soluble organic material utilizing the membrane |
| JPS6193802A (en) * | 1984-10-15 | 1986-05-12 | Agency Of Ind Science & Technol | Separation of liquid mixture |
| JPS6295105A (en) * | 1985-10-16 | 1987-05-01 | イ−・アイ・デユポン・デ・ニモアス・アンド・カンパニ− | Method for coating composite reverse osmosis membrane |
-
1988
- 1988-08-02 JP JP19213588A patent/JPH0242397A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS588505A (en) * | 1981-07-08 | 1983-01-18 | Toyobo Co Ltd | Semi-permeable composite membrane |
| JPS6125608A (en) * | 1984-07-14 | 1986-02-04 | Agency Of Ind Science & Technol | Separating film for water-soluble organic material and separation of water-soluble organic material utilizing the membrane |
| JPS6193802A (en) * | 1984-10-15 | 1986-05-12 | Agency Of Ind Science & Technol | Separation of liquid mixture |
| JPS6295105A (en) * | 1985-10-16 | 1987-05-01 | イ−・アイ・デユポン・デ・ニモアス・アンド・カンパニ− | Method for coating composite reverse osmosis membrane |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014062737A (en) * | 2012-09-19 | 2014-04-10 | Mitsubishi Heavy Ind Ltd | Method and apparatus for detoxifying incineration ash containing radioactive cesium |
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