JPS646438B2 - - Google Patents
Info
- Publication number
- JPS646438B2 JPS646438B2 JP15471582A JP15471582A JPS646438B2 JP S646438 B2 JPS646438 B2 JP S646438B2 JP 15471582 A JP15471582 A JP 15471582A JP 15471582 A JP15471582 A JP 15471582A JP S646438 B2 JPS646438 B2 JP S646438B2
- Authority
- JP
- Japan
- Prior art keywords
- radioactive waste
- dielectric loss
- volume
- water
- heat generation
- 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
- 239000002901 radioactive waste Substances 0.000 claims description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 29
- 239000000126 substance Substances 0.000 claims description 18
- 238000010438 heat treatment Methods 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 17
- 239000007787 solid Substances 0.000 claims description 13
- 230000020169 heat generation Effects 0.000 claims description 11
- 238000002844 melting Methods 0.000 claims description 11
- 230000008018 melting Effects 0.000 claims description 10
- 230000003647 oxidation Effects 0.000 claims description 8
- 238000007254 oxidation reaction Methods 0.000 claims description 8
- 239000002699 waste material Substances 0.000 claims description 8
- 239000003054 catalyst Substances 0.000 claims description 7
- 238000005979 thermal decomposition reaction Methods 0.000 claims description 7
- 230000001737 promoting effect Effects 0.000 claims description 6
- 238000002485 combustion reaction Methods 0.000 claims description 5
- 238000001704 evaporation Methods 0.000 claims description 5
- 239000011521 glass Substances 0.000 claims description 5
- 230000001678 irradiating effect Effects 0.000 claims description 3
- 230000008020 evaporation Effects 0.000 claims description 2
- 238000007496 glass forming Methods 0.000 claims 2
- 239000000155 melt Substances 0.000 claims 2
- 150000003609 titanium compounds Chemical class 0.000 claims 1
- 238000011038 discontinuous diafiltration by volume reduction Methods 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 239000000047 product Substances 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- 239000000843 powder Substances 0.000 description 7
- 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 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 6
- 239000000654 additive Substances 0.000 description 6
- 239000003456 ion exchange resin Substances 0.000 description 6
- 229920003303 ion-exchange polymer Polymers 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 5
- 229910010413 TiO 2 Inorganic materials 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
- 239000011347 resin Substances 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 3
- YDZQQRWRVYGNER-UHFFFAOYSA-N iron;titanium;trihydrate Chemical compound O.O.O.[Ti].[Fe] YDZQQRWRVYGNER-UHFFFAOYSA-N 0.000 description 3
- 239000010802 sludge Substances 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 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
- 229910052799 carbon Inorganic materials 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
- 230000007423 decrease Effects 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 235000013980 iron oxide Nutrition 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000011707 mineral Substances 0.000 description 2
- 229910052573 porcelain Inorganic materials 0.000 description 2
- 239000012857 radioactive material Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 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
- 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
- 238000006243 chemical reaction Methods 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
- 239000010949 copper Substances 0.000 description 1
- 229910052802 copper Inorganic materials 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
- 150000004679 hydroxides Chemical class 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
- 238000002156 mixing Methods 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
- 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
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 description 1
- 229910052861 titanite Inorganic materials 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
場合は、加熱が進んで含有水分が失なわれた時点
でエネルギの吸収が激減し、発熱作用が衰え、熱
反応及び溶融を行なうことが困難であり、また、
可能であつても非常に時間がかかる欠点があつ
た。
発明者らは、この欠点を除去するため多くの実
験を行ない、研究を重ね、そのときに得られた知
見に基づき本発明がなされた。
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、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んに発熱が行なわれ蒸発する
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。
本発明は、含水放射性廃棄物に予め誘電損失
ε・tanδの大なる発熱促進物質を添加混合してお
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引続き加
熱溶融、熱分解、燃焼が有効に行なわれ、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、誘電損
失ε・tanδが、前記放射性廃棄物の乾燥無水固形
分の誘電損失よりも大なる値を有する発熱促進物
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。
本発明につき、実施例も含め以下説明する。
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、コバルトの水酸化物や酸化物が主成分
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) 誘電損失ε・tanδの値が大きいこと。
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。この値
は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、発熱
促進物質として作用し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。
(2) 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。
(3) その溶融固化物がガラス質、セラミツク質或
い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。
(4) 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。
また、酸化触媒を用いて発熱促進を行なうこ
ともできる。
(5) 放射性廃棄物をマイクロ波で燃焼させる場
合、残渣に炭素が残ると燃焼が持続しないの
で、炭素の酸化を促進する性能があること。即
ち、酸化触媒を用いて発熱が促進される。
(6) 上記の酸化触媒(鉄、銅などの酸化物など)
と共存するか、固容体となり得ること。
以上の添加物質の例を次に挙げる。
(1),(2),(3),(4)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, as the heating progresses and the water content is lost, energy absorption drastically decreases, the exothermic effect weakens, and it is difficult to carry out thermal reactions and melting.
Even if it was possible, it had the disadvantage of being very time consuming. In order to eliminate this drawback, the inventors conducted many experiments and conducted repeated research, and based on the knowledge obtained at that time, the present invention was made. 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 values of dielectric loss ε and tan δ of the dry anhydrous solid content of the water-containing radioactive waste described above are extremely small, and the calorific value is also extremely small. 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 liquid, boric acid-based concentrated waste liquid and concentrated waste water from washing water contain about 90% water by weight, and even sodium sulfate-based concentrated waste liquid contains about 80% water by weight. If such water-containing radioactive waste containing a large amount of water is continuously irradiated with microwaves, it will actively generate heat and evaporate while the water remains, but once it reaches an anhydrous dry state, the microwave The absorption capacity of the liquid 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 the present invention, by adding and mixing a heat generation accelerating substance with large dielectric loss ε and tan δ to water-containing radioactive waste in advance, during the microwave irradiation process,
Even when the moisture evaporates and the water becomes dry, heating, melting, thermal decomposition, and combustion continue to take place effectively. During the process, there is no need for the above-mentioned operations to suppress reflection, and the process is simple and short. The object of the present invention is to provide a method for heating and reducing the volume of radioactive waste, which can reduce the volume by heating in a short period of time. In the present invention, a heat generation promoting substance having a dielectric loss ε and tan δ larger than the dielectric loss of dry anhydrous solid content of the radioactive waste is added to radioactive waste in a water-containing state, and then microwaves are applied. This is a heating volume reduction method for radioactive waste, which is characterized in that the volume is reduced by irradiation, evaporation removal of moisture, and heating and melting. The present invention will be described below, including examples. 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 hydroxides and oxides of manganese, iron, and cobalt, 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) The value of dielectric loss ε・tanδ is large. 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 this value be as large as possible, but ε・
It is preferable that tanδ≧0.01. By selecting this characteristic, as mentioned above, it acts as an exothermic accelerator and continues heating even in the anhydrous state, making it possible to perform effective heat-melting volume reduction without the need for any intermediate operations. can. As described above, if volume reduction can be carried out effectively, handling becomes easier in the next step of solidification or encapsulation in a solid, and the scale of 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. (2) Clad, especially its ability to contain, retain, or have a strong affinity for radioactive materials. (3) 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. (4) Since a glassy 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. Furthermore, heat generation can also be promoted using an oxidation catalyst. (5) When burning radioactive waste using microwaves, if carbon remains in the residue, combustion will not continue, so it must have the ability to promote carbon oxidation. That is, heat generation is promoted using an oxidation catalyst. (6) The above oxidation catalysts (oxides of iron, copper, etc.)
coexist with or be able to form a solid substance. Examples of the above additive substances are listed below. (1), (2), (3), (4) (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 baked in a microwave,
It becomes BaTiO 3 and CaTiO 3 . (d) Titanium ironite (ilmenite) and titanite 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。
(3)の特性を有するもの
(a) ガラス質形成のための材料(ガラス質形成物
質)
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) 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)。
(5)の特性を有するもの
酸化触媒として、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
等。
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。
実験例 1
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、周波数2450MHz、印加電力5KWの
実験炉で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
10gを得た。
同じ試験材料にBaTiO3粉末10g又は酸化触媒
としてFe2O310g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。
実験例 2
含水率65%のイオン交換樹脂86gに(水中での
体積330ml、重量350g)BaTiO3粉末10gを予め
添加混合したものを周波数2450MHz、マイクロ波
印加電力5KWの実験炉で照射した。約25分後の
灼熱成分はBaTiO3も含め9gに減少した。この
うち樹脂の灼熱成分は2g以下であつた。この減
容係数は以下の通りとなつた。
減容係数:350/9=39
即ち1/39に減少したことになる。
なお、ここでいう減容係数とは次式で表わされ
るものをいう。
減容係数=処理前の廃樹脂スラリー量(g)/処理後
の重量(g)
本発明は、含水状態の放射性廃棄物に、誘電損
失ε・tanδが、前記放射性廃棄物の乾燥無水固形
分の誘電損失よりも大なる値を有する発熱促進物
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を行なつて減容することに
より、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 forms a glass-like substance when it is melted and then 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 Items having the characteristics of (3) (a) Materials for forming glass (vitreous forming substances) One or more of the following: CaO, Na 2 O, SiO 2 , Al 2 O 3 , MgO, K 2 O,
PbO, CaF2 , etc. (b) PWR boric acid waste liquid (same product as borosilicate vitrified product is obtained). Items with characteristics (5) Oxidation catalysts include copper oxide, iron oxide (Fe 3 O 4 , etc.), cobalt oxide, nickel oxide, chromium oxide, etc. Additionally, additive substances having the above characteristics (1) to (6) are:
At least one type of those belonging to (1) is always included, but other types may be used without, or in combination of one or any plurality of types. 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. Experimental example 1 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 microwave irradiation was performed using 200g in an experimental reactor with a frequency of 2450MHz and applied power of 5KW, approximately 35
A scorching powder component consisting of a trace amount of carbide in about a minute
Obtained 10g. When the same test material was mixed with 10g of BaTiO 3 powder or 10g of Fe 2 O 3 as an oxidation catalyst and irradiated with microwaves in the same way, the results were approximately 20%.
The thermal decomposition, combustion, and scorching heat ended after 1 minute or about 22 minutes, making it possible to shorten the time. Reducing process time means reducing equipment or expanding equipment capacity. Experimental Example 2 10 g of BaTiO 3 powder was added and mixed in advance to 86 g of ion exchange resin with a water content of 65% (volume in water: 330 ml, weight: 350 g) and irradiated in an experimental furnace with a frequency of 2450 MHz and a microwave applied power of 5 KW. After about 25 minutes, the scorching components including BaTiO 3 were reduced to 9 g. Of these, the scorching component of the resin was 2 g or less. This volume reduction factor was as follows. Volume reduction factor: 350/9=39, that is, the volume was reduced to 1/39. Incidentally, the volume reduction coefficient referred to here is expressed by the following formula. Volume reduction factor=Amount of waste resin slurry before treatment (g)/Weight after treatment (g) The present invention uses radioactive waste in a water-containing state to reduce the dielectric loss ε and tan δ of the dry anhydrous solid content of the radioactive waste. After adding a heat generation accelerating substance that has a value greater than the dielectric loss of We have been able to provide a heating volume reduction method for radioactive waste that can effectively reduce the volume in a short time by continuing heating, melting, combustion, and thermal decomposition, which is extremely important from a practical and safety standpoint. This has the following effects.
Claims (1)
tanδが、前記放射性廃棄物の乾燥無水固形分の誘
電損失よりも大なる値を有する発熱促進物質を添
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。 2 前記発熱促進物質の誘電損失が、 ε・tanδ≧0.01 である特許請求の範囲第1項記載の方法。 3 前記発熱促進物質の添加率が、前記廃棄物の
乾燥無水固形分に対し、重量比で2〜50%である
特許請求の範囲第1項記載の方法。 4 前記発熱促進物質が、チタン化合物である特
許請求の範囲第1項記載の方法。 5 含水状態の放射性廃棄物に、誘電損失ε・
tanδが、前記放射性廃棄物の乾燥無水固形分の誘
電損失よりも大なる値を有する発熱促進物質及び
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。 6 含水状態の放射性廃棄物に、誘電損失ε・
tanδが、前記放射性廃棄物の乾燥無水固形分の誘
電損失よりも大なる値を有する発熱促進物質及び
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。 7 含水状態の放射性廃棄物に、誘電損失ε・
tanδが、前記放射性廃棄物の乾燥無水固形分の誘
電損失よりも大なる値を有する発熱促進物質、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。[Claims] 1 Radioactive waste in a water-containing state has dielectric loss ε・
After adding a heat generation promoting substance whose tan δ is larger than the dielectric loss of the dry anhydrous solid content of the radioactive waste, microwave is irradiated to remove water by evaporation and heat melting, combustion or thermal decomposition. A method for reducing the volume of radioactive waste by heating. 2. The method according to claim 1, wherein the heat generation promoting substance has a dielectric loss of ε·tanδ≧0.01. 3. The method according to claim 1, wherein the addition rate of the heat generation promoting substance is 2 to 50% by weight based on the dry anhydrous solid content of the waste. 4. The method according to claim 1, wherein the heat generation promoting substance is a titanium compound. 5 Radioactive waste in a water-containing state has dielectric loss ε・
After adding a heat generation accelerator and an oxidation catalyst having tan δ larger than the dielectric loss of the dry anhydrous solid content of the radioactive waste, irradiating with microwaves,
A method for heating and reducing the volume of radioactive waste, which comprises reducing the volume by evaporating water, melting, burning or thermal decomposition. 6 Radioactive waste in a water-containing state has dielectric loss ε・
After adding a heat generation promoting substance having a tan δ larger than the dielectric loss of the dry anhydrous solid content of the radioactive waste and a glass forming substance that melts to form glass, irradiating with microwaves, A method for heating and reducing the volume of radioactive waste, which comprises reducing the volume by evaporating water, melting, burning or thermal decomposition. 7 Radioactive waste in a water-containing state has dielectric loss ε・
After adding an exothermic substance whose tan δ is larger than the dielectric loss of the dry anhydrous solid content of the radioactive waste, an oxidation catalyst, and a glass-forming substance that melts to form glass, microwaves are applied. irradiate,
A method for heating and reducing the volume of radioactive waste, which comprises reducing the volume by evaporating water, melting, burning or thermal decomposition.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15471582A JPS5944698A (en) | 1982-09-07 | 1982-09-07 | Method of heating and volume-decreasing radioactive waste |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15471582A JPS5944698A (en) | 1982-09-07 | 1982-09-07 | Method of heating and volume-decreasing radioactive waste |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5944698A JPS5944698A (en) | 1984-03-13 |
JPS646438B2 true JPS646438B2 (en) | 1989-02-03 |
Family
ID=15590374
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP15471582A Granted JPS5944698A (en) | 1982-09-07 | 1982-09-07 | Method of heating and volume-decreasing radioactive waste |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5944698A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007034816A1 (en) * | 2005-09-20 | 2007-03-29 | Inter-University Research Institute National Institutes Of Natural Sciences | Method for modification of asbestos |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0185931B1 (en) * | 1984-12-25 | 1991-07-24 | Ebara Corporation | Method and apparatus for processing waste matter |
IL106460A (en) * | 1993-07-23 | 1997-09-30 | Palboard Ltd | Method of recycling plastic materials |
-
1982
- 1982-09-07 JP JP15471582A patent/JPS5944698A/en active Granted
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2007034816A1 (en) * | 2005-09-20 | 2007-03-29 | Inter-University Research Institute National Institutes Of Natural Sciences | Method for modification of asbestos |
Also Published As
Publication number | Publication date |
---|---|
JPS5944698A (en) | 1984-03-13 |
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