JPS646439B2 - - Google Patents
Info
- Publication number
- JPS646439B2 JPS646439B2 JP15520182A JP15520182A JPS646439B2 JP S646439 B2 JPS646439 B2 JP S646439B2 JP 15520182 A JP15520182 A JP 15520182A JP 15520182 A JP15520182 A JP 15520182A JP S646439 B2 JPS646439 B2 JP S646439B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- volume
- radioactive waste
- heating
- radioactive
- 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
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 27
- 239000002901 radioactive waste Substances 0.000 claims description 24
- 230000003647 oxidation Effects 0.000 claims description 15
- 238000007254 oxidation reaction Methods 0.000 claims description 15
- 238000010438 heat treatment Methods 0.000 claims description 14
- 239000003054 catalyst Substances 0.000 claims description 11
- 238000000034 method Methods 0.000 claims description 11
- 238000002844 melting Methods 0.000 claims description 10
- 239000000126 substance Substances 0.000 claims description 9
- 238000002485 combustion reaction Methods 0.000 claims description 8
- 230000008018 melting Effects 0.000 claims description 7
- 238000005979 thermal decomposition reaction Methods 0.000 claims description 7
- 238000011038 discontinuous diafiltration by volume reduction Methods 0.000 claims description 6
- 239000011521 glass Substances 0.000 claims description 4
- 230000008020 evaporation Effects 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 3
- 239000000155 melt Substances 0.000 claims description 2
- 238000007496 glass forming Methods 0.000 claims 1
- 239000000047 product Substances 0.000 description 8
- 239000002699 waste material Substances 0.000 description 8
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 239000000654 additive Substances 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- 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 5
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 5
- 229910010413 TiO 2 Inorganic materials 0.000 description 5
- 239000003456 ion exchange resin Substances 0.000 description 5
- 229920003303 ion-exchange polymer Polymers 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 229910004298 SiO 2 Inorganic materials 0.000 description 4
- 230000000996 additive effect Effects 0.000 description 4
- 230000002285 radioactive effect Effects 0.000 description 4
- 239000010936 titanium Substances 0.000 description 4
- 229910052719 titanium Inorganic materials 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 230000020169 heat generation Effects 0.000 description 3
- YDZQQRWRVYGNER-UHFFFAOYSA-N iron;titanium;trihydrate Chemical compound O.O.O.[Ti].[Fe] YDZQQRWRVYGNER-UHFFFAOYSA-N 0.000 description 3
- 230000001678 irradiating effect Effects 0.000 description 3
- 239000010802 sludge Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 2
- 239000004327 boric acid Substances 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 235000013980 iron oxide Nutrition 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910052573 porcelain Inorganic materials 0.000 description 2
- 239000012857 radioactive material Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- 239000005751 Copper oxide Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 239000010426 asphalt Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 229910000428 cobalt oxide Inorganic materials 0.000 description 1
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910000431 copper oxide Inorganic materials 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000005538 encapsulation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000002241 glass-ceramic Substances 0.000 description 1
- 230000003100 immobilizing effect Effects 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 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
- 239000000203 mixture Substances 0.000 description 1
- 229910000480 nickel oxide Inorganic materials 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000000941 radioactive substance Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 239000011265 semifinished product Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Processing Of Solid Wastes (AREA)
Description
本発明は原子力発電所などにおいて発生する放
射性廃棄物を廃棄処理するのに便なるよう、加熱
溶融して減容せしめる放射性廃棄物の加熱減容方
法に関するものである。
原子力利用産業が盛んになるにつれ、放射性廃
棄物の処理の問題も増大して来る。現在行なわれ
ている処理方法としては、放射性廃棄物を何等か
の方法で減容固化したものをアスフアルトやコン
クリート中に封じ込んで海洋や陸地の投棄場所に
投棄している。しかしながら将来放射性廃棄物の
発生量は急激に増加することが予想され、一方投
棄場所には限度があるので、できるだけ減容する
ことが必要になつて来る。
放射性廃棄物のうち、イオン交換樹脂、プレコ
ートフイルタスラツジ（セルローズ粉末、イオン
交換せんい、イオン交換樹脂粉末など）は水分を
多く含んだ状態で回収されるが、従来は最終処理
まで行なわれず単に貯留されている程度の処理し
かなされていなかつた。しかし、この種の廃棄物
も引続き発生量が増大するので対策が必要であ
る。これらの含水放射性廃棄物も中間処理として
減容することが必要となるが、最近、減容方法と
してマイクロ波の照射により加熱を行ない水分を
除却し溶融を行ない減容することが試みられてい
る。
しかしながら、マイクロ波照射により加熱する
場合、燃焼や熱分解した場合、残渣には炭素が残
り熱反応が持続しない欠点があつた。
本発明は、含水放射性廃棄物に予め酸化触媒を
添加混合したる後マイクロ波照射を行なうことに
より、従来の方法における上記の欠点を除き、熱
反応が完全に終了し、十分な減容効果を挙げるこ
とができる放射性廃棄物の加熱減容方法を提供す
ることを目的とするものである。
本発明は、含水状態の放射性廃棄物に、酸化触
媒を添加したる後、マイクロ波を照射し、水分の
蒸発除去及び加熱溶融、燃焼又は熱分解を行なつ
て減容することを特徴とする放射性廃棄物の加熱
減容方法である。
酸化触媒としては酸化銅、酸化鉄（Fe3O4な
ど）、酸化コバルト、酸化ニツケル、酸化クロム
などのうちの一種或いは複数種が用いられ、予め
酸化触媒を添加混入しておけば、マイクロ波照射
により水分がなくなつた後も炭素の酸化が促進さ
れ、発熱促進物質として作用し、引続き発熱を行
ない、ガラス質があればこれを溶融し、また、炭
素はCO2として排ガス中に排出され減容をはかる
ことができる。
マイクロ波照射の場合は、廃棄物に水分が含ま
れている場合はエネルギを吸収して十分な発熱作
用が得られるが、水分がなくなり乾燥状態になる
とエネルギを吸収しなくなり発熱しなくなる。こ
の場合予め酸化触媒が加えてあれば炭素の酸化が
促進され発熱し、加熱減容が続行される。
即ち誘電体にマイクロ波を照射したとき、マイ
クロ波が誘電体中に吸収されるエネルギは、その
誘電体が持つ比誘電率εと誘電正接tanδとの積で
ある誘電損失ε・tanδの大きさに比例する。そし
て、水は誘電率ε＝80.5、誘電正接tanδ＝0.31、
即ち誘電損失はε・tanδ＝25であり、種々の誘電
体の中でも非常に大きな値を示し、従つてマイク
ロ波のエネルギをよく吸収して発熱する物質であ
る。一方、前述の含水放射性廃棄物の乾燥無水固
形分の誘電損失ε・tanδの値は非常に小さく、マ
イクロ波のエネルギを殆んど吸収せず、発熱量も
極めて少ない。
例えば、イオン交換樹脂はポリスチレンで作ら
れているが、ポリスチレンは比誘電率ε＝2.54、
誘電正接tanδ＝2.3×10-4、従つて誘電損失ε・
tanδ＝5.84×10-4となり、水に比べ約43000分の
１の微少値に過ぎない。また、プレコートフイル
タスラツジのセルローズについては乾燥セルロー
ズ粉末の誘電損失ε・tanδは水の約500分の１に
過ぎない。
原子力発電所で発生する放射性含水イオン交換
樹脂やフイルタスラツジのスラリーは、沈降分離
や遠心分離などの予備脱水を行なつた後でも、70
〜90重量％の水分を含んでいる。また、放射性濃
縮廃液に関しては、ほう酸系の濃縮廃液や洗たく
排水の濃縮排液は約90重量％の水分を含み、硫酸
ナトリウム系の濃縮廃液でも約80重量％の水分を
含んでいる。
このような水分を多く含んでいる含水放射性廃
棄物にマイクロ波を照射し続けていると、水分が
残存している間は盛に発熱が行われ蒸発するが、
無水乾燥状態に達するとマイクロ波の吸収能力が
著しく低下して発熱作用がなくなり溶融減容が極
めて困難となる。
マイクロ波エネルギの吸収能力が低下するとい
うことは、照射したマイクロ波の大部分が反射さ
れてしまい有効利用されないことにあるので、実
際の操作においては反射量を極力低減するために
マイクロ照射装置の導波管中のＥ相チユーナ、Ｈ
相チユーナを操作する必要がある。しかも放射性
物質からの放射線による操作員の被ばくを避ける
ために遠隔操作をせねばならない。
これらの欠点を改良するために、発明者らは多
くの実験と研究とを重ね、本発明をなすに至つた
もので、含水放射性廃棄物に予め酸化触媒を添加
混合しておくことにより、マイクロ波照射の工程
の途中で、水分が蒸発し、無水乾燥状態になつて
も炭素の酸化を促進し引続き加熱溶融、燃焼、熱
分解が有効に行なわれ、途中で、反射抑制のため
の上記の操作などを全く必要とせず、簡単なプロ
セスにて短時間で加熱減容を行なうことができ
る。
例えば原子力発電所で発生する濃縮液、使用済
みイオン交換樹脂スラリーやフイルタスラツジス
ラリには、原子炉系統の水配管系から発生する放
射性腐蝕生成物（以下クラツドと称する）を含ん
でいる。このクラツドは、Mn−54，Fe−59，Co
−59，Co−60等を主たる放射性物質とするマン
ガン、鉄、コバルトの水中酸化物が主成分であ
る。
このような放射性廃棄物をマイクロ波照射する
に当たり、有効な加熱減容を行なうために、添加
物質を加える。その添加物質としては次の如き特
性を有するものが選ばれる。
(1) 酸化触媒（理由は前述の通り）の作用を有す
ること。
(2) 上記の酸化触媒と共存するか、固容体となり
得ること。
(3) 発熱促進物質として誘電損失ε・tanδが大き
い物質であること。
放射性廃棄物の乾燥無水固形分の誘電損失
ε・tanδよりも大きい値のものを選ぶ。できる
だけ大きいことが望ましいが、ε・tanδ≧0.01
とすることが好ましい。この特性を選択するこ
とにより、前述されたる如く、無水状態になつ
ても加熱が続行され、何等中間的な操作を要す
ることなく、有効な加熱溶融減容を行なうこと
ができる。
以上の如く、有効な減容を行なうことができ
れば、次の工程として固化或いは固体の中に封
じ込める固形化を行なうに当たつて取り扱いが
容易となり、設備規模も縮小せしめることがで
き、設備費、保守費を低減することができるほ
か、さらに最終工程である投棄に当たつても扱
い量が減り、投棄場所不足の問題を緩和し、ま
た、投棄設備を小規模として設備費、保守費を
低減することができる。
さらに、マイクロ波照射プロセスと同時に固
化を行なう場合には、次の如き特性の一つ或い
は複数種の特性を有する添加物質を更に予め添
加しておく。
(4) クラツド、特にその放射性物質を封じ込める
能力、保留する能力或いは親和力が強いこと。
(5) その溶融固化物がガラス質、セラミツク質或
はスラグ状のものであり、放射性廃棄物の加熱
減容残滓を固形化ないし固定化するのに比較的
適していること。
(6) 最終減容固化物としてガラス状固化体を製造
することがあるため、SiO2，Al2O3，CaO等と
溶融固化物中に共存し得ること。
(3)，(4)，(5)，(6)につき添加物質の例を次に挙げ
る。
(3)，(4)，(5)，(6)の特性を有するもの
(a) 900MHz〜11GHzのマイクロ波領域において
チタン酸塩及びチタン酸は、表１に示す如く比
誘電率εと誘電正接tanδが大きい。
The present invention relates to a method for reducing the volume of radioactive waste by heating and melting it to facilitate the disposal of radioactive waste generated at nuclear power plants and the like. As nuclear energy use industries become more popular, the problem of radioactive waste disposal also increases. The current disposal method is to use some method to reduce the volume of radioactive waste, solidify it, encapsulate it in asphalt or concrete, and dump it at dumping sites in the ocean or on land. However, the amount of radioactive waste generated is expected to increase rapidly in the future, and there are limits to the number of dumping locations, so it will be necessary to reduce the volume as much as possible. Among radioactive waste, ion exchange resin and pre-coated filter sludge (cellulose powder, ion exchange fiber, ion exchange resin powder, etc.) are collected in a state containing a large amount of moisture, but conventionally they are simply stored without undergoing final treatment. Only the extent of treatment was done. However, as the amount of this type of waste generated continues to increase, countermeasures are necessary. These water-containing radioactive wastes also need to be reduced in volume as an intermediate treatment, but recently attempts have been made to reduce the volume by heating with microwave irradiation to remove moisture and melting. . However, when heating by microwave irradiation, combustion or thermal decomposition, carbon remains in the residue and the thermal reaction cannot be sustained. The present invention eliminates the above-mentioned drawbacks of the conventional method by adding and mixing an oxidation catalyst to water-containing radioactive waste in advance and then irradiating it with microwaves, thereby completely completing the thermal reaction and achieving a sufficient volume reduction effect. The purpose of the present invention is to provide a method for reducing the volume of radioactive waste by heating. The present invention is characterized in that after adding an oxidation catalyst to radioactive waste in a water-containing state, it is irradiated with microwaves to remove water by evaporation, and is subjected to thermal melting, combustion, or thermal decomposition to reduce the volume. This is a method for heating and reducing the volume of radioactive waste. As the oxidation catalyst, one or more of copper oxide, iron oxide (Fe 3 O 4 , etc.), cobalt oxide, nickel oxide, chromium oxide, etc. is used. Even after moisture is removed by irradiation, carbon oxidation is promoted, acting as a heat generation accelerator, continuing to generate heat, melting any glassy substance, and carbon is emitted into the exhaust gas as CO 2 . It is possible to reduce the volume. In the case of microwave irradiation, if the waste contains moisture, it absorbs energy and generates sufficient heat, but when the moisture is removed and the waste becomes dry, it no longer absorbs energy and generates no heat. In this case, if an oxidation catalyst is added in advance, the oxidation of carbon will be promoted and heat will be generated, and heating and volume reduction will continue. In other words, when a dielectric is irradiated with microwaves, the energy absorbed by the microwave in the dielectric is determined by the dielectric loss ε・tanδ, which is the product of the dielectric constant ε and the dielectric loss tangent tanδ. is proportional to. Water has a dielectric constant ε = 80.5, a dielectric loss tangent tan δ = 0.31,
That is, the dielectric loss is ε·tan δ=25, which is a very large value among various dielectric materials, and therefore it is a material that absorbs microwave energy well and generates heat. On the other hand, the dielectric loss ε and tan δ of the dry anhydrous solid content of the water-containing radioactive waste described above is extremely small, absorbs almost no microwave energy, and has an extremely low calorific value. For example, ion exchange resin is made of polystyrene, which has a dielectric constant ε=2.54,
Dielectric loss tangent tanδ=2.3×10 -4 , therefore dielectric loss ε・
tanδ=5.84×10 -4 , which is only about 1/43000th of water. Furthermore, regarding the cellulose of pre-coated filter sludge, the dielectric loss ε and tan δ of dry cellulose powder is only about 1/500 of that of that of cellulose. Slurry of radioactive hydrated ion exchange resin and filter slurry generated at nuclear power plants has a 70%
Contains ~90% water by weight. Concerning radioactive concentrated waste fluids, boric acid-based concentrated waste fluids and concentrated wastewater from washing water contain approximately 90% water by weight, and even sodium sulfate-based concentrated waste fluids contain approximately 80% water by weight. If such water-containing radioactive waste containing a large amount of water is continuously irradiated with microwaves, as long as the water remains, heat will be generated rapidly and it will evaporate.
When the anhydrous dry state is reached, the microwave absorption ability is significantly reduced and the exothermic effect disappears, making it extremely difficult to melt and reduce the volume. A decrease in the absorption ability of microwave energy means that most of the irradiated microwaves are reflected and are not used effectively. Therefore, in actual operation, the micro irradiation equipment should be adjusted to reduce the amount of reflection as much as possible. E-phase tuner in waveguide, H
It is necessary to operate Aichiyuna. Moreover, it must be operated remotely to avoid exposing operators to radiation from radioactive materials. In order to improve these drawbacks, the inventors conducted many experiments and research, and came up with the present invention. By adding and mixing an oxidation catalyst to water-containing radioactive waste in advance, During the process of wave irradiation, water evaporates, and even if the state becomes anhydrous and dry, the oxidation of carbon is promoted, and heating, melting, combustion, and thermal decomposition continue to take place effectively. No operation is required, and the volume can be reduced by heating in a short time using a simple process. For example, concentrated liquid, used ion exchange resin slurry, and filter sludge generated at nuclear power plants contain radioactive corrosion products (hereinafter referred to as crud) generated from the water piping system of the nuclear reactor system. This cladding consists of Mn-54, Fe-59, Co
The main components are oxides of manganese, iron, and cobalt in water, with main radioactive substances such as -59 and Co-60. When irradiating radioactive waste with microwaves, additives are added to effectively reduce the volume by heating. As the additive substance, one having the following characteristics is selected. (1) It has the action of an oxidation catalyst (the reason is as mentioned above). (2) Coexist with the above oxidation catalyst or be able to form a solid state. (3) As a heat generation promoting substance, it must be a substance with large dielectric loss ε and tan δ. Select one with a value larger than the dielectric loss ε and tan δ of the dry anhydrous solid content of radioactive waste. It is desirable that it be as large as possible, but ε・tanδ≧0.01
It is preferable that By selecting this characteristic, as described above, heating continues even in an anhydrous state, and effective heat-melting volume reduction can be performed without any intermediate operations. As described above, if the volume can be effectively reduced, it will be easier to handle in the next step of solidification or encapsulation in a solid, and the scale of the equipment can be reduced, reducing equipment costs and In addition to reducing maintenance costs, the amount handled during the final process of dumping is also reduced, alleviating the problem of lack of dumping space, and reducing equipment and maintenance costs by making the dumping equipment smaller. can do. Further, when solidifying is performed simultaneously with the microwave irradiation process, an additive substance having one or more of the following properties is further added in advance. (4) Craft, especially its ability to contain, retain, or have a strong affinity for radioactive materials. (5) The melted and solidified material is glassy, ceramic, or slag-like, and is relatively suitable for solidifying or immobilizing the heat-reduced volume residue of radioactive waste. (6) Since a glass-like solidified product may be produced as the final volume-reduced solidified product, SiO 2 , Al 2 O 3 , CaO, etc. may coexist in the molten solidified product. Examples of additive substances for (3), (4), (5), and (6) are listed below. (3), (4), (5), (6) (a) In the microwave region of 900MHz to 11GHz, titanate and titanic acid have the relative permittivity ε and dielectric constant as shown in Table 1. Tangent tanδ is large.
【表】
(b) セラミツク的性質を有するものとしては、表
２に示す如きチタン磁器及びチタン酸磁器が用
いられる。[Table] (b) Titanium porcelain and titanate porcelain as shown in Table 2 are used as those having ceramic properties.
【表】
(c) 混合、焼成すれば(a)，(b)になるもの。
例えばBaCO3とTiO2或いはCaCO3とTiO2と
を混合して添加しマイクロ波にて焼成すれば
BaTiO3，CaTiO3になる。
(d) スラグ状の固体を作り、かつ鉄の酸化物との
共存性を有する（前記(6)の特性）という特性の
ものとしては、チタン鉄鉱（イルメナイト）や
チタン鉄鉱岩（イルメニタイト）等があり、そ
の組成は表３の如くである。[Table] (c) Things that become (a) and (b) when mixed and fired. For example, if BaCO 3 and TiO 2 or CaCO 3 and TiO 2 are mixed and added and fired in a microwave,
It becomes BaTiO 3 and CaTiO 3 . (d) Titanium ironite (ilmenite) and titanium ironite rock (ilmenitite) have the characteristics of forming a slag-like solid and having coexistence with iron oxides (characteristics in (6) above). The composition is shown in Table 3.
【表】
ここに見られるようにTiO2は鉄とよく共存
するのみならず、ガラスの成分であるSiO2，
Al2O3，CaOとも共存し得る。
その他、チタン酸化物やチタン酸塩を少なか
らず含有する鉱物の粉粒体を用いてもよい。
(e) イルメナイト系溶接棒の被覆材はチタンを含
むイルメナイト系鉱物を原料としており、この
原材料、半製品或いは製品を用いてもよい。こ
の材料は溶融した後、冷却するとガラス状の物
質を形成する。
(f) 強誘電性のガラスセラミツクとしては、
BaTiO3−BaO−TiO2−Al2O3系
（ε＝1200，tanδ＝0.025）
PbTiO3−PbO−TiO2−Al2O3−SiO2系
（ε＝100，tanδ＝0.008）
などがあり、ガラスの成分であるPbO，NaO
とも共存する。
(5)の特性を有するもの
(a) ガラス質形成のための材料
次のもののうちの一つ又は複数種類。
CaO，Na2O，SiO2，Al2O3，MgO，K2O，
PbO，CaF2等。
(b) NGK焼却炉で得た紙の灰（ガラス成分を多
量に含有する）。
(c) PWRほう酸廃液（ほう硅酸ガラス固化体と
同じものが得られる）。
なお以上の(1)〜(6)の特性を有する添加物質は、
(1)に属するものの少なくとも一種類のものは必ず
含まれるがその他のものは、なくとも、或いは、
一つ又は任意の複数の種類を組み合わせて用いて
もよい。
これらの添加物質の量は、多過ぎると減容率が
小になるので、放射性廃棄物の乾燥固形分に対
し、２〜50％の範囲、好ましくは10〜20％の範囲
で加えるのがよい。次に実験例を示す。
放射性含水廃棄物を模擬した試験材料としてカ
チオン粉末樹脂とアニオン粉末樹脂とを乾燥重量
比３：１に混合し、水分は70重量％としたもの
200ｇを用い、2450MHz、5KWのマイクロ波照射
を行なつたところ、約35分間で微量の炭化物から
なる粉粒状の灼熱成分約５ｇを得た。
同じ試験材料にBaTiO3粉末３ｇ又は酸化触媒
としてFe3O45ｇを予め添加混合したものに、同
様マイクロ波照射を行なつたところそれぞれ約20
分後又は約22分後に熱分解、燃焼、灼熱が終了
し、時間短縮することができた。プロセス時間の
短縮は、設備の縮小或いは設備能力の拡大を意味
する。
本発明は、含水状態の放射性廃棄物に、酸化触
媒を添加したる後、マイクロ波を照射し、水分の
蒸発除去及び加熱溶融、燃焼又は熱分解を行なつ
て減容することにより、残渣中の炭素の酸化が促
進され、水分が失なわれても発熱が続行され、引
続き加熱、溶融、燃焼、熱分解を行ない、短時間
で有効な減容を行なうことができる放射性廃棄物
の加熱減容方法を提供することができ、実用上、
保安上極めて大なる効果を有するものである。[Table] As seen here, TiO 2 not only coexists well with iron, but also with SiO 2 , which is a component of glass.
It can also coexist with Al 2 O 3 and CaO. In addition, mineral powder containing a considerable amount of titanium oxide or titanate may also be used. (e) The coating material of the ilmenite welding rod is made from ilmenite mineral containing titanium, and this raw material, semi-finished product, or finished product may be used. This material melts and then forms a glass-like substance when cooled. (f) Ferroelectric glass ceramics include BaTiO 3 −BaO−TiO 2 −Al 2 O 3 system (ε=1200, tanδ=0.025) PbTiO 3 −PbO−TiO 2 −Al 2 O 3 −SiO 2 system (ε=100, tanδ=0.008), and PbO, NaO, which are components of glass.
coexist with (a) Materials for glassy formation One or more of the following: CaO, Na 2 O, SiO 2 , Al 2 O 3 , MgO, K 2 O,
PbO, CaF2 , etc. (b) Paper ash obtained from the NGK incinerator (contains a large amount of glass). (c) PWR boric acid waste liquid (same product as borosilicate vitrified product is obtained). Additionally, additive substances having the above characteristics (1) to (6) are:
At least one of the items in (1) must be included, but other items may not be included, or
One type or a combination of arbitrary plural types may be used. If the amount of these additives is too large, the volume reduction rate will be small, so it is best to add them in a range of 2 to 50%, preferably in a range of 10 to 20%, based on the dry solid content of radioactive waste. . Next, an experimental example will be shown. As a test material simulating radioactive water-containing waste, cationic powder resin and anionic powder resin were mixed at a dry weight ratio of 3:1, and the water content was 70% by weight.
When 200g was used and microwave irradiation was performed at 2450MHz and 5KW, about 5g of a powdery scorching component consisting of a trace amount of carbide was obtained in about 35 minutes. When the same test material was mixed with 3g of BaTiO 3 powder or 5g of Fe 3 O 4 as an oxidation catalyst and irradiated with microwaves in the same way, the results were approximately 20%.
The thermal decomposition, combustion, and scorching heat were completed after 1 minute or about 22 minutes, making it possible to shorten the time. Reducing process time means reducing equipment or expanding equipment capacity. The present invention involves adding an oxidation catalyst to radioactive waste in a water-containing state, irradiating it with microwaves, removing water by evaporation, and reducing the volume by heat-melting, combustion, or thermal decomposition. The oxidation of carbon in the radioactive waste is promoted, and even if water is lost, heat generation continues, and heating, melting, combustion, and pyrolysis continue to occur, resulting in effective volume reduction in a short period of time. In practice,
This has an extremely large effect on security.
Claims (1)
したる後、マイクロ波を照射し、水分の蒸発除去
及び加熱溶融、燃焼又は熱分解を行なつて減容す
ることを特徴とする放射性廃棄物の加熱減容方
法。 ２ 含水状態の放射性廃棄物に、酸化触媒及び溶
融してガラス質を形成するガラス質形成物質を添
加したる後、マイクロ波を照射し、水分の蒸発除
去及び加熱溶融、燃焼又は熱分解を行なつて減容
することを特徴とする放射性廃棄物の加熱減容方
法。[Scope of Claims] 1. After adding an oxidation catalyst to radioactive waste in a water-containing state, it is irradiated with microwaves to evaporate and remove water, and is subjected to heat melting, combustion, or thermal decomposition to reduce the volume. Features: A heating volume reduction method for radioactive waste. 2. After adding an oxidation catalyst and a glass-forming substance that melts and forms glass to radioactive waste in a water-containing state, microwave is irradiated to remove water by evaporation, and heat-melting, combustion, or thermal decomposition is performed. A method for heating and reducing the volume of radioactive waste, which is characterized by reducing the volume by heating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15520182A JPS5944699A (en) | 1982-09-08 | 1982-09-08 | Method of heating and volume-decreasing radioactive waste |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15520182A JPS5944699A (en) | 1982-09-08 | 1982-09-08 | Method of heating and volume-decreasing radioactive waste |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5944699A JPS5944699A (en) | 1984-03-13 |
| JPS646439B2 true JPS646439B2 (en) | 1989-02-03 |
Family
ID=15600703
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15520182A Granted JPS5944699A (en) | 1982-09-08 | 1982-09-08 | Method of heating and volume-decreasing radioactive waste |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5944699A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0310002U (en) * | 1989-06-20 | 1991-01-30 |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3583595D1 (en) * | 1984-12-25 | 1991-08-29 | Ebara Corp | METHOD AND DEVICE FOR TREATING WASTE MATERIAL. |
| US20110224474A1 (en) * | 2010-03-09 | 2011-09-15 | Kurion, Inc. | Advanced Microwave System for Treating Radioactive Waste |
-
1982
- 1982-09-08 JP JP15520182A patent/JPS5944699A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0310002U (en) * | 1989-06-20 | 1991-01-30 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5944699A (en) | 1984-03-13 |
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