JPH0565039B2 - - Google Patents
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- Publication number
- JPH0565039B2 JPH0565039B2 JP20737185A JP20737185A JPH0565039B2 JP H0565039 B2 JPH0565039 B2 JP H0565039B2 JP 20737185 A JP20737185 A JP 20737185A JP 20737185 A JP20737185 A JP 20737185A JP H0565039 B2 JPH0565039 B2 JP H0565039B2
- Authority
- JP
- Japan
- Prior art keywords
- solidified
- waste solvent
- parts
- pvc
- weight
- 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
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- 238000007711 solidification Methods 0.000 claims description 23
- 230000008023 solidification Effects 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 16
- 239000003795 chemical substances by application Substances 0.000 claims description 15
- 229920000642 polymer Polymers 0.000 claims description 15
- 239000002250 absorbent Substances 0.000 claims description 14
- 230000002745 absorbent Effects 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 11
- 239000000843 powder Substances 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 claims description 8
- 239000002901 radioactive waste Substances 0.000 claims description 8
- 239000002904 solvent Substances 0.000 claims description 8
- 238000003756 stirring Methods 0.000 claims description 7
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 claims description 4
- 150000003014 phosphoric acid esters Chemical class 0.000 claims description 4
- 239000011347 resin Substances 0.000 claims 2
- 229920005989 resin Polymers 0.000 claims 2
- 239000010887 waste solvent Substances 0.000 description 25
- SNRUBQQJIBEYMU-UHFFFAOYSA-N dodecane Chemical compound CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 description 21
- STCOOQWBFONSKY-UHFFFAOYSA-N tributyl phosphate Chemical compound CCCCOP(=O)(OCCCC)OCCCC STCOOQWBFONSKY-UHFFFAOYSA-N 0.000 description 17
- 239000000463 material Substances 0.000 description 12
- 239000000047 product Substances 0.000 description 12
- 229920001944 Plastisol Polymers 0.000 description 9
- 239000004999 plastisol Substances 0.000 description 9
- 239000007788 liquid Substances 0.000 description 7
- 230000000704 physical effect Effects 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 4
- 239000012188 paraffin wax Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 3
- 239000000292 calcium oxide Substances 0.000 description 3
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 3
- 239000004014 plasticizer Substances 0.000 description 3
- 229920001187 thermosetting polymer Polymers 0.000 description 3
- 239000004034 viscosity adjusting agent Substances 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 2
- 230000000740 bleeding effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 230000002285 radioactive effect Effects 0.000 description 2
- 238000012958 reprocessing Methods 0.000 description 2
- 238000000638 solvent extraction Methods 0.000 description 2
- 239000002915 spent fuel radioactive waste Substances 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 229910052778 Plutonium Inorganic materials 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 125000005396 acrylic acid ester group Chemical group 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 150000008280 chlorinated hydrocarbons Chemical class 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000004992 fission Effects 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- -1 for example Substances 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 239000003230 hygroscopic agent Substances 0.000 description 1
- 125000005395 methacrylic acid group Chemical group 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 229940094933 n-dodecane Drugs 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 description 1
- 229920000636 poly(norbornene) polymer Polymers 0.000 description 1
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 1
- 229910001948 sodium oxide Inorganic materials 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000012749 thinning agent Substances 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
- C08J3/09—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in organic liquids
- C08J3/091—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in organic liquids characterised by the chemical constitution of the organic liquid
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K11/00—Use of ingredients of unknown constitution, e.g. undefined reaction products
- C08K11/005—Waste materials, e.g. treated or untreated sewage sludge
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
- G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
- G21F9/04—Treating liquids
- G21F9/06—Processing
- G21F9/16—Processing by fixation in stable solid media
- G21F9/167—Processing by fixation in stable solid media in polymeric matrix, e.g. resins, tars
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
- C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
- C08J2327/04—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing chlorine atoms
- C08J2327/06—Homopolymers or copolymers of vinyl chloride
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- High Energy & Nuclear Physics (AREA)
- General Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Processing Of Solid Wastes (AREA)
- Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
Description
〈産業上の利用分野〉
この発明は、使用済核燃料再処理における溶媒
抽出法等で用いられた放射性廃溶媒、特にリン酸
トリブチルの如きリン酸系エステルを含む廃溶媒
の固化処理方法に関するものである。
〈従来の技術〉
原子炉の使用済核燃料を再処理して核分裂生成
物をウランやプルトニウムから分離除去する方法
としては、溶媒抽出法が最も広く用いられてい
る。この方法には一般にドデカンの如き炭化水素
で希釈されたリン酸トリブチル（以下、「TBP」
と略記する）が溶媒として使用されるが、使用済
のTBPを処理するに際しては、これが放射性廃
棄物であるため、その処理方法には十分な配慮が
必要となる。
TBPを含む放射性廃溶媒（以下、「TBP含有
廃溶媒」と略記する）の処理方法としては、この
廃溶媒を固化処理する方法が従来から試みられて
おり、例えば、TBPが塩化ビニル樹脂（以下、
「PVC」と略記する）を可塑化する性質を有して
いることに着目して、TBP含有廃溶媒と細片状
PVCとを混合してTBP含有廃溶媒を固化処理す
る方法が提案されている（特公昭53−32040号）。
また、本願と同一出願人により特許出願された
固化処理方法として、多官能性アクリル系または
メタクリル系単量体といつた熱硬化性可塑剤を含
有するPVCプラスチゾルをTBP含有廃溶媒と混
合、撹拌し、必要に応じて加熱処理して固化させ
る方法がある（特願昭59−30042号）。
〈発明が解決しようとする問題点〉
しかしながら上述した従来方法は、いずれも必
ずしも満足すべきものではない。すなわち、細片
状PVCと撹拌混合する固化処理方法によれば、
TBPはPVCに吸収膨潤するだけなので流動性は
示さなくなるものの、軟らかいプデイング状の粘
度の固化体となるに過ぎない。これを撹拌後加熱
すれば固化体の硬度は向上するが、PVCは熱伝
導性が悪いため長時間の加熱が必要であり、しか
も固化体の径が大きくなると内部まで熱が伝わり
にくくなり、内部が表面より著しく硬度の低い固
化体しか得られない。廃溶媒中に含まれるドデカ
ン量が多くなるほどこの傾向が甚しい。
一方、PVCプラスチゾルと混合する固化処理
方法によれば、外観、機械的強度（硬度、圧縮強
度）、均質性といつた固化体物性において比較的
良好な固化体が得られるが、特に100とサイズ
の大きな固化体を得る場合には固化体物性に改良
の余地がある。すなわち、PVCプラスチゾルと
TBP含有廃溶媒との混合物を低温加熱固化処理
したときには、外観や均質性は良好であるが機械
的強度が若干低い。この理由は、PVCプラスチ
ゾル調製時に粘度調整剤としてパラフインの使用
が不可欠であり、このPVCプラスチゾルをTBP
含有廃溶媒と混合すると、廃溶媒中に含まれる一
定量のドデカンの他に粘度調整剤としてのパラフ
インが加算され、固化対象廃溶媒全量に占める炭
化水素総量（パラフイン＋ドデカン）が増加する
ことになり、その結果得られる固化体の機械的強
度が低下するものと考えられる。また、機械的強
度を向上させるためにPVCプラスチゾルとTBP
含有廃溶媒との混合物を高温で長時間加熱固化処
理したときは、加熱停止後に固化体外周部で放熱
に伴うPVCの収縮に起因する固化体の収縮現象
が生じるのに対し、固化体内部では蓄熱された熱
量が放熱されないために残留熱応力が発生する
が、硬化後の熱硬化性可塑剤の抗応力を超える
と、固化体内部にクラツクが発生しやすいという
問題がある。
そこでこの発明は、上述したごとき従来技術に
おける欠点を解消し、低温加熱固化処理によつて
も外観、機械強度、均質性がいずれも良好で優れ
た物性の固化体を得ることができる放射性廃溶媒
の固化処理方法を提供することを目的としてなさ
れたものである。
〈問題点を解決するための手段〉
この発明による放射性廃溶媒の固化処理方法
は、TBP含有廃溶媒に固化処理剤としてPVC粉
末、弾性ポリマーおよび吸湿剤を添加し撹拌混合
したのち、この混合物を加熱して固化させること
を特徴とするものである。
この発明による固化処理の対象となる放射性廃
溶媒としては、放射性核種を含有したTBP等の
リン酸系エステルのほか、リン酸系エステルと脂
肪族炭化水素、芳香族炭化水素、塩素化炭化水
素、鉱油、水等との混合物が挙げられる。
この発明において固化処理剤として用いる各成
分の使用割合は、PVC粉末100重量部に対し一般
的には弾性ポリマー２〜10重量部および吸湿剤５
〜25重量部である。
この発明で用いられるPVCとしては、塩化ビ
ニル単独重合体、塩化ビニルとこれと共重合可能
な単量体との共重合体、さらにはこられの混合物
等から選ぶことができる。
弾性ポリマーは引裂力に対する抗力を固化体に
付与し、加熱停止後の固化体収縮現象に伴うクラ
ツク発生を防止するとともに、併せて、それ自身
が有する吸油性によりTBP含有廃溶媒中のドデ
カンを吸収し、固化体内部の機械的強度低下の一
因となるドデカンをできるだけ低減せしめること
によつて、固化体の機械的強度を高め、同時に固
化体からのドデカンのブリードを防止する。かよ
うなドデカン吸収性を有する弾性ポリマーとして
は、ポリノルボーネン等の物質が知られており、
例えば「ノーソレツクス」（CdF Chimie社（フ
ランス）製商品名）が市販品として入手できる。
吸湿剤は、TBP含有廃溶媒中に混入している
水分を吸湿除去して、加熱固化処理時に水分の揮
発に起因する固化体内部の発泡現象を防止すると
ともに、吸湿に伴う発生水和反応熱により固化体
中心部の温度を上昇させ、固化体の機械的強度を
向上させるものである。吸湿剤としては、例えば
酸化カルシウム、酸化バリウム、酸化ナトリウ
ム、塩化カルシウム等が好ましく使用できる。
この発明を実施するに際しては、先ず上述した
PVC粉末、弾性ポリマーおよび吸湿剤を放射性
廃溶媒と混合し、混合物をプラネタリーミキサ
ー、ニーダー、バタフライミキサー、ヘンシエル
ミキサー、デイゾルバー、リボンブレンダー、ス
テータスミキサー、撹拌ペラ等の慣用的装置で良
く撹拌混合する。
廃溶媒と固化処理剤との混合割合は、廃溶媒
100重量部に対して固化処理剤（PVC粉末、弾性
ポリマーおよび吸湿剤の合計量）80〜120重量部
の範囲が好ましい。
次いでこの混合物を容器外部から加熱し、一般
的には80〜100℃の温度で約７時間固化処理を施
すことによつて物性の優れた固化体を得ることが
できる。
〈実施例〉
以下に実施例および比較例を挙げてこの発明を
詳述する。なお「％」および「部」はいずれも重
量基準を表わす。
実施例 １
固化処理する廃溶媒とて、TBP85％、ｎ−ド
デカン10％および水５％からなる非放射性模擬廃
溶媒を調製し、この廃溶媒50Kgを100ドラム缶
内に投入した。
次に廃溶媒に対する固化処理剤の混合比が46/5
４（重量比）となるように、固化処理剤を投入し
た。固化処理剤各成分の使用割合は下表に示した
通りとした。
なお、PVC粉末は「ゼオン43B」（日本ゼオン
(株)製）、弾性ポリマーは「ノーソレツクス」、およ
び吸湿剤は酸化カルシウム「CML＃31」（近江化
学(株)製）を使用した。
次にドラム缶内の廃溶媒と固化処理剤をインド
ラムミキサーにより室温にて約１時間撹拌混合し
た。撹拌に伴い混合液の液温が約10℃上昇したも
のの、混合液の粘度は約250cpsと低かつた。
次にドラム缶内の混合液を低周波誘導加熱器に
より約80℃で約７時間加熱処理して固化体とし
た。なお、加熱後は加熱器フードを被せたまま約
16時間自然放冷させた。
得られた固化体の表面および内部のシヨアＡ硬
度（JIS Ｋ−7215）を測定したところ40〜50とな
り、比較的均質な物性を示した。中心部の固化体
サンプルの圧縮強度（JIS Ｋ−7208）を測定した
ところ11.5Kg／cm2であつた。また、固化体表面や
内部にクラツク発生は認められなかつた。
実施例 ２
固化処理剤のPVC粉末、吸湿剤および弾性ポ
リマーの使用割合を下表に示すようにし、廃溶
媒／固化処理剤の混合比を37/63とした以外は、
実施例１と同様にして固化処理を行なつた。な
お、約１時間撹拌、混合したときの混合液粘度は
約800cpsまで上昇した。
得られた固化体の表面および内部のシヨアＡ硬
度は全体に均質で80〜85の硬度を示した。中心部
の固化体サンプルの圧縮強度は24.0Kg／cm2であつ
た。また、固化体表面に細かいクラツクが発生し
ていたが、内部にはクラツクの発生は認められな
かつた。
比較例 １
吸湿剤と弾性ポリマーを用いずにPVC粉末の
みを固化処理剤として用いた以外は、実施例１と
同様にして固化処理を行なつた。
得られた固化体表面のシヨアＡ硬度は25〜50を
示しているが、内部は殆んど０以下でありプデイ
ング状を呈していた。また、固化体表面および内
部に大きなクラツクが多数発生していた。
比較例 ２
弾性ポリマーを用いずにPVC粉末と吸湿剤を
固化処理剤として用いた以外は、実施例１と同様
にして固化処理を行なつた。
得られた固化体の表面硬度はドラム周辺部で
55、ドラム中央部で10を示し、また固化体内部硬
度は中央部中心で30〜45、低部で０以下となりプ
デイング状を呈し、全体的に不均質な固化体とな
つた。また、固化体表面に大きなクラツクが発生
していた。
比較例 ３
PVC「ゼオン135J」（日本ゼオン(株)製）100部
PVC「ゼオン121」（日本ゼオン(株)製） 10部
吸湿剤（酸化カルシウム「CML＃31」） 50部
弾性ポリマー「ノーソレツクス」 13部
熱硬化性可塑剤（アクリル酸エステル） 70部
減粘剤「Ｗ−212−Ｊ」（勝田化工(株)製） ５部
粘度調整剤（ｎ−パラフイン） 13部
上記の成分をプラネタリーミキサー中で混合
し、真空脱泡することによつてPVCプラスチゾ
ルを調製した。
次に実施例１で用いた非放射性模擬廃溶媒と上
記PVCプラスチゾルとを、廃溶媒／PVCプラス
チゾルの混合比が40/60（重量比）となるように
100ドラム缶内に投入し、インドラムミキサー
により室温にて約40分間撹拌混合した。混合液の
液温は約15℃上昇したものの、混合液の粘度は約
40cpsと低かつた。
次にドラム缶内の混合液を低周波誘導加熱器に
より約80℃で約７時間加熱処理して固化体とし
た。
得られた固化体の表面および内部のシヨアＡ硬
度を測定したところ、表面は５〜30、内部は10〜
15を示したが、低部は０〜３と軟らかく、全体的
に不均質な固化体となつた。また、固化体表面に
はクラツクはなかつたが、内部には大きなクラツ
クが発生していた。
<Industrial Application Field> The present invention relates to a method for solidifying radioactive waste solvents used in solvent extraction methods in spent nuclear fuel reprocessing, particularly waste solvents containing phosphate esters such as tributyl phosphate. be. <Prior Art> Solvent extraction is the most widely used method for reprocessing spent nuclear fuel from nuclear reactors to separate and remove fission products from uranium and plutonium. This method generally involves tributyl phosphate (hereinafter referred to as "TBP") diluted with a hydrocarbon such as dodecane.
) is used as a solvent, but when disposing of used TBP, as it is radioactive waste, sufficient consideration must be given to the disposal method. As a treatment method for radioactive waste solvent containing TBP (hereinafter abbreviated as "TBP-containing waste solvent"), a method of solidifying this waste solvent has been attempted in the past. ,
Focusing on the property of plasticizing TBP-containing waste solvent (abbreviated as "PVC"),
A method of solidifying TBP-containing waste solvent by mixing it with PVC has been proposed (Japanese Patent Publication No. 32040/1983). In addition, as a solidification treatment method that has been patented by the same applicant as the present application, PVC plastisol containing a thermosetting plasticizer such as a polyfunctional acrylic or methacrylic monomer is mixed with a TBP-containing waste solvent and stirred. However, if necessary, there is a method of solidifying by heat treatment (Japanese Patent Application No. 59-30042). <Problems to be Solved by the Invention> However, none of the above-mentioned conventional methods are necessarily satisfactory. In other words, according to the solidification treatment method of stirring and mixing with strip-like PVC,
Since TBP simply absorbs and swells into PVC, it no longer exhibits fluidity, but it merely becomes a solidified material with a soft pudding-like viscosity. If this is stirred and then heated, the hardness of the solidified material will improve, but PVC has poor thermal conductivity, so long heating is required.Moreover, as the diameter of the solidified material increases, it becomes difficult for heat to be transmitted to the inside. However, only a solidified material whose hardness is significantly lower than that of the surface can be obtained. This tendency becomes more serious as the amount of dodecane contained in the waste solvent increases. On the other hand, according to the solidification treatment method of mixing with PVC plastisol, a solidified product with relatively good physical properties such as appearance, mechanical strength (hardness, compressive strength), and homogeneity can be obtained. When obtaining a large solidified material, there is room for improvement in the physical properties of the solidified material. i.e. PVC plastisol and
When the mixture with TBP-containing waste solvent is solidified by heating at low temperature, the appearance and homogeneity are good, but the mechanical strength is slightly low. The reason for this is that it is essential to use paraffin as a viscosity modifier when preparing PVC plastisol, and this PVC plastisol is
When mixed with the contained waste solvent, paraffin as a viscosity modifier is added to the fixed amount of dodecane contained in the waste solvent, increasing the total amount of hydrocarbons (paraffin + dodecane) in the total amount of waste solvent to be solidified. It is considered that the mechanical strength of the resulting solidified product decreases. We also use PVC plastisol and TBP to improve mechanical strength
When the mixture with the contained waste solvent is heated and solidified at high temperature for a long period of time, shrinkage of the solidified body occurs at the outer periphery of the solidified body after heating is stopped due to contraction of PVC due to heat dissipation, whereas inside the solidified body, shrinkage occurs. Residual thermal stress occurs because the accumulated heat is not radiated, but if it exceeds the resistance stress of the thermosetting plasticizer after curing, there is a problem that cracks are likely to occur inside the solidified body. Therefore, the present invention solves the above-mentioned drawbacks of the conventional technology and makes it possible to obtain a solidified product with good appearance, mechanical strength, homogeneity, and excellent physical properties even by low-temperature heat solidification treatment. The purpose of this study was to provide a solidification treatment method. <Means for Solving the Problems> The radioactive waste solvent solidification treatment method according to the present invention involves adding PVC powder, an elastic polymer, and a moisture absorbent as a solidification treatment agent to the TBP-containing waste solvent, stirring and mixing the mixture, and then stirring and mixing the mixture. It is characterized by being heated and solidified. Radioactive waste solvents that can be subjected to solidification treatment according to the present invention include phosphoric acid esters such as TBP containing radionuclides, as well as phosphoric acid esters and aliphatic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons, Mixtures with mineral oil, water, etc. may be mentioned. In this invention, the proportion of each component used as a solidifying agent is generally 2 to 10 parts by weight of elastic polymer and 5 parts by weight of moisture absorbent per 100 parts by weight of PVC powder.
~25 parts by weight. The PVC used in this invention can be selected from vinyl chloride homopolymers, copolymers of vinyl chloride and monomers copolymerizable therewith, and mixtures thereof. The elastic polymer provides resistance to tearing force to the solidified material, prevents the occurrence of cracks due to shrinkage of the solidified material after heating is stopped, and also absorbs dodecane in the TBP-containing waste solvent due to its own oil absorption properties. However, by reducing dodecane, which is a cause of a decrease in mechanical strength inside the solidified body, as much as possible, the mechanical strength of the solidified body is increased, and at the same time, bleeding of dodecane from the solidified body is prevented. Substances such as polynorbornene are known as elastic polymers that have such dodecane absorbability.
For example, "Nosolex" (trade name, manufactured by CdF Chimie (France)) is available as a commercial product. The hygroscopic agent absorbs and removes the water mixed in the TBP-containing waste solvent, and prevents the foaming phenomenon inside the solidified material caused by the volatilization of water during the heat solidification process. This increases the temperature at the center of the solidified body and improves the mechanical strength of the solidified body. As the moisture absorbent, for example, calcium oxide, barium oxide, sodium oxide, calcium chloride, etc. can be preferably used. When carrying out this invention, first the above-mentioned
PVC powder, elastic polymer, and moisture absorbent are mixed with radioactive waste solvent, and the mixture is well stirred and mixed using conventional equipment such as a planetary mixer, kneader, butterfly mixer, Henschel mixer, dissolver, ribbon blender, status mixer, stirring peller, etc. do. The mixing ratio of waste solvent and solidification treatment agent is
The solidifying agent (total amount of PVC powder, elastic polymer and moisture absorbent) is preferably in the range of 80 to 120 parts by weight per 100 parts by weight. Next, this mixture is heated from outside the container and subjected to a solidification treatment, generally at a temperature of 80 to 100°C for about 7 hours, to obtain a solidified product with excellent physical properties. <Examples> The present invention will be described in detail below with reference to Examples and Comparative Examples. Note that both "%" and "part" are based on weight. Example 1 As a waste solvent to be solidified, a non-radioactive simulated waste solvent consisting of 85% TBP, 10% n-dodecane and 5% water was prepared, and 50 kg of this waste solvent was put into a 100 drum can. Next, the mixing ratio of solidification treatment agent to waste solvent is 46/5.
The solidification treatment agent was added so that the weight ratio was 4 (weight ratio). The proportions of each component of the solidification treatment agent were as shown in the table below. The PVC powder is "Zeon 43B" (Nippon Zeon)
(manufactured by Ohmi Kagaku Co., Ltd.), the elastic polymer was "Nosolex", and the moisture absorbent was calcium oxide "CML #31" (manufactured by Ohmi Chemical Co., Ltd.). Next, the waste solvent and solidification agent in the drum were stirred and mixed at room temperature for about 1 hour using an in-drum mixer. Although the temperature of the mixed liquid increased by about 10°C with stirring, the viscosity of the mixed liquid remained low at about 250 cps. Next, the mixed liquid in the drum was heat-treated at about 80° C. for about 7 hours using a low-frequency induction heater to solidify it. After heating, leave the heater hood on for approx.
It was left to cool naturally for 16 hours. The Shore A hardness (JIS K-7215) of the surface and interior of the obtained solidified body was measured to be 40 to 50, indicating relatively homogeneous physical properties. The compressive strength (JIS K-7208) of the solidified sample in the center was measured and found to be 11.5 Kg/cm 2 . Furthermore, no cracks were observed on the surface or inside the solidified material. Example 2 The proportions of PVC powder, moisture absorbent, and elastic polymer used in the solidification treatment agent were as shown in the table below, and the mixing ratio of waste solvent/solidification treatment agent was 37/63.
Solidification treatment was carried out in the same manner as in Example 1. Note that the viscosity of the mixed liquid increased to about 800 cps after stirring and mixing for about 1 hour. The Shore A hardness of the surface and interior of the obtained solidified product was uniform throughout and showed a hardness of 80 to 85. The compressive strength of the solidified sample in the center was 24.0 Kg/cm 2 . Further, although fine cracks were observed on the surface of the solidified body, no cracks were observed inside. Comparative Example 1 A solidification treatment was carried out in the same manner as in Example 1, except that only PVC powder was used as the solidification treatment agent without using a moisture absorbent or an elastic polymer. The Shore A hardness of the surface of the obtained solidified product was 25 to 50, but the inside was almost 0 or less and had a pudding-like appearance. In addition, many large cracks were found on the surface and inside of the solidified product. Comparative Example 2 Solidification treatment was carried out in the same manner as in Example 1, except that PVC powder and a moisture absorbent were used as the solidification treatment agent without using an elastic polymer. The surface hardness of the obtained solidified material is around the drum.
55, and 10 at the center of the drum, and the internal hardness of the solidified product was 30 to 45 at the center, and 0 or less at the bottom, giving a pudding-like appearance and becoming a non-uniform solidified product as a whole. In addition, large cracks were observed on the surface of the solidified material. Comparative example 3 PVC “Zeon 135J” (Nippon Zeon Co., Ltd.) 100 parts PVC “Zeon 121” (Nippon Zeon Co., Ltd.) 10 parts Moisture absorbent (calcium oxide “CML #31”) 50 parts Elastic polymer “Nosolex” 13 parts Thermosetting plasticizer (acrylic acid ester) 70 parts Thinning agent "W-212-J" (manufactured by Katsuta Kako Co., Ltd.) 5 parts Viscosity modifier (n-paraffin) 13 parts PVC plastisol was prepared by mixing in a Lee mixer and vacuum defoaming. Next, the non-radioactive simulated waste solvent used in Example 1 and the above PVC plastisol were mixed so that the waste solvent/PVC plastisol mixing ratio was 40/60 (weight ratio).
The mixture was placed in a 100 drum and stirred and mixed at room temperature for about 40 minutes using an in-drum mixer. Although the temperature of the mixed liquid increased by approximately 15℃, the viscosity of the mixed liquid remained approximately
It was low at 40cps. Next, the mixed liquid in the drum was heat-treated at about 80° C. for about 7 hours using a low-frequency induction heater to solidify it. When the Shore A hardness of the surface and inside of the obtained solidified body was measured, the surface was 5-30 and the inside was 10-30.
15, but the lower part was soft with a value of 0 to 3, resulting in an overall heterogeneous solidified product. Further, although there were no cracks on the surface of the solidified product, large cracks were found inside.
【表】
〈発明の効果〉
以上説明したように、この発明においては
PVC粉末、弾性ポリマーおよび吸湿剤を固化処
理剤として用いたために、80℃程度の比較的低温
の加熱固化処理によつても外観、機械的強度、均
質性といつた物性がいずれも良好な固化体を得る
ことができるのである。
特にこの発明においてはドデカン吸収性を有す
る弾性ポリマーを使用したために、加熱停止後の
固化体内部に発生する熱応力に伴う引裂力に対す
る抗力を固化体に付与し、クラツクの発生を防止
することができ、さらには廃溶媒中に含まれるド
デカンに起因する固化体内部の機械的強度低下現
象を減少させ、固化体内部の機械的強度を向上さ
せるとともに、固化体からのブリードを防止し、
全体に均質な固化体を得ることができる。[Table] <Effects of the invention> As explained above, in this invention,
Because PVC powder, elastic polymer, and moisture absorbent are used as solidifying agents, good physical properties such as appearance, mechanical strength, and homogeneity are achieved even when heat solidifying at a relatively low temperature of about 80°C. You can get a body. In particular, in this invention, since an elastic polymer having dodecane absorption properties is used, it is possible to impart resistance to the tearing force accompanying thermal stress generated inside the solidified body after heating is stopped, and to prevent the occurrence of cracks. Furthermore, it reduces the mechanical strength reduction phenomenon inside the solidified body caused by dodecane contained in the waste solvent, improves the mechanical strength inside the solidified body, and prevents bleeding from the solidified body.
A homogeneous solidified body can be obtained throughout.
Claims (1)
に、固化処理剤として塩化ビニル樹脂粉末、弾性
ポリマーおよび吸湿剤を添加し撹拌混合したの
ち、この混合物を加熱して固化させることを特徴
とする放射性廃溶媒の固化処理方法。 ２ 前記固化処理剤各成分の使用割合は、塩化ビ
ニル樹脂粉末100重量部に対し、弾性ポリマー２
〜10重量部および吸湿剤５〜25重量部である特許
請求の範囲第１項記載の固化処理方法。[Claims] 1. Adding vinyl chloride resin powder, an elastic polymer, and a moisture absorbent as a solidifying agent to a radioactive waste solvent containing a phosphoric acid ester, stirring and mixing the mixture, and then heating and solidifying the mixture. A method for solidifying radioactive waste solvent, characterized by: 2 The usage ratio of each component of the solidification treatment agent is 2 parts by weight of elastic polymer for 100 parts by weight of vinyl chloride resin powder.
10 parts by weight of the moisture absorbent and 5 to 25 parts by weight of the moisture absorbent.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20737185A JPS6266198A (en) | 1985-09-19 | 1985-09-19 | Method of solidifying and processing radioactive waste solvent |
| FR8612979A FR2591513B1 (en) | 1985-09-19 | 1986-09-17 | METHOD FOR SOLIDIFYING A RESIDUAL RADIOACTIVE SOLVENT CONTAINING A PHOSPHORIC ESTER |
| DE19863631794 DE3631794A1 (en) | 1985-09-19 | 1986-09-18 | METHOD FOR SOLIDIFYING RADIOACTIVE WASTE SOLVENT |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20737185A JPS6266198A (en) | 1985-09-19 | 1985-09-19 | Method of solidifying and processing radioactive waste solvent |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6266198A JPS6266198A (en) | 1987-03-25 |
| JPH0565039B2 true JPH0565039B2 (en) | 1993-09-16 |
Family
ID=16538615
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20737185A Granted JPS6266198A (en) | 1985-09-19 | 1985-09-19 | Method of solidifying and processing radioactive waste solvent |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS6266198A (en) |
| DE (1) | DE3631794A1 (en) |
| FR (1) | FR2591513B1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9217594D0 (en) * | 1992-08-19 | 1992-09-30 | Reads Plc | Process for the treatment of sludge |
| GB2477924A (en) * | 2010-02-17 | 2011-08-24 | Encapsuwaste Ltd | A method of encapsulating waste material |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2135328A1 (en) * | 1971-07-15 | 1973-02-01 | Kraftwerk Union Ag | Radio-active waste disposal - esp for liquid concentrate which is mixed with plastic powder and dried |
| US4148745A (en) * | 1973-06-16 | 1979-04-10 | Gesellschaft Fur Kernforschung M.B.H. | Method of preparing phosphoric acid esters for non-polluting storage by incorporation in polyvinyl chloride |
| DE2330845C2 (en) * | 1973-06-16 | 1982-09-23 | Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe | Process for the solidification of radioactively contaminated phosphoric acid esters with a polymer |
| DE2363474C3 (en) * | 1973-12-20 | 1986-02-13 | Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe | Process for the solidification of waste liquids containing essentially organic, radioative or toxic substances |
| CH654436A5 (en) * | 1983-04-29 | 1986-02-14 | Syncrete Sa | PROCESS FOR COATING RADIOACTIVE WASTE. |
| JPS60173499A (en) * | 1984-02-20 | 1985-09-06 | 動力炉・核燃料開発事業団 | Method of solidifying radioactive waste solvent |
-
1985
- 1985-09-19 JP JP20737185A patent/JPS6266198A/en active Granted
-
1986
- 1986-09-17 FR FR8612979A patent/FR2591513B1/en not_active Expired - Fee Related
- 1986-09-18 DE DE19863631794 patent/DE3631794A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE3631794C2 (en) | 1990-05-10 |
| DE3631794A1 (en) | 1987-07-30 |
| FR2591513A1 (en) | 1987-06-19 |
| FR2591513B1 (en) | 1991-04-12 |
| JPS6266198A (en) | 1987-03-25 |
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