JPS5837200A - Removing method for oxide on metallic surface - Google Patents
Removing method for oxide on metallic surfaceInfo
- Publication number
- JPS5837200A JPS5837200A JP13272281A JP13272281A JPS5837200A JP S5837200 A JPS5837200 A JP S5837200A JP 13272281 A JP13272281 A JP 13272281A JP 13272281 A JP13272281 A JP 13272281A JP S5837200 A JPS5837200 A JP S5837200A
- Authority
- JP
- Japan
- Prior art keywords
- oxide
- corrosion
- water
- base metal
- oxides
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 230000002829 reductive effect Effects 0.000 claims abstract description 13
- 239000010953 base metal Substances 0.000 claims abstract description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 21
- 239000002184 metal Substances 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 230000007797 corrosion Effects 0.000 abstract description 17
- 238000005260 corrosion Methods 0.000 abstract description 17
- 229910052742 iron Inorganic materials 0.000 abstract description 16
- 239000000126 substance Substances 0.000 abstract description 10
- 238000004090 dissolution Methods 0.000 abstract description 9
- 238000007664 blowing Methods 0.000 abstract description 7
- SZVJSHCCFOBDDC-UHFFFAOYSA-N ferrosoferric oxide Chemical compound O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 abstract description 4
- 230000007423 decrease Effects 0.000 abstract description 2
- 239000012530 fluid Substances 0.000 abstract description 2
- 230000001629 suppression Effects 0.000 abstract 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 34
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 12
- 239000000498 cooling water Substances 0.000 description 7
- 229910052760 oxygen Inorganic materials 0.000 description 7
- 229910052786 argon Inorganic materials 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 229910000975 Carbon steel Inorganic materials 0.000 description 5
- 239000010962 carbon steel Substances 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 230000001172 regenerating effect Effects 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 230000002285 radioactive effect Effects 0.000 description 4
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- 238000005341 cation exchange Methods 0.000 description 3
- 238000007872 degassing Methods 0.000 description 3
- 238000010828 elution Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000003456 ion exchange resin Substances 0.000 description 3
- 229920003303 ion-exchange polymer Polymers 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 239000012153 distilled water Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005868 electrolysis reaction Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005536 corrosion prevention Methods 0.000 description 1
- 238000005202 decontamination Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- -1 iron ions Chemical class 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 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
- 230000009897 systematic effect Effects 0.000 description 1
- 239000012498 ultrapure water Substances 0.000 description 1
Landscapes
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Abstract
Description
【発明の詳細な説明】
金属表面に成長又は付着した酸化物の除去に係シ、特に
母材である金属の腐食損傷を防止するのに好適な金属表
面酸化物の除去方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the removal of oxides grown or attached to metal surfaces, and particularly to a method for removing oxides from metal surfaces suitable for preventing corrosion damage to base metals.
火力発電プラント、原子力発電プラントおよび化学プラ
ント等のプラントに設置されている機器および配管の流
体と接触する内面には、プラントの稼動年数の増加に伴
って酸化物が付着、又は成長する。このような酸化物は
、機器および配管の機能を阻害する危険性があるので、
これを除去することが望まれる。Oxides adhere to or grow on the inner surfaces of equipment and piping installed in plants such as thermal power plants, nuclear power plants, chemical plants, etc. that come into contact with fluid as the number of years the plants have been in operation increases. Such oxides have the risk of interfering with the functionality of equipment and piping, so
It is desirable to remove this.
特に原子力発電プラントにおいては、原子力発電プラン
ト内を流動する冷却水中の放射性イオン等が、原子力発
電プラントの機器および配管の内面に付着する酸化物に
付着したり、又は機器および配管の内面に酸化物が形成
されるときに酸化物に取り込まれる。この結果、機器、
及び配管の表面線量率が増加するので機器、及び配管の
保守点検作業に支障をきたし、作業に要する時間が著し
する必要がある。Particularly in nuclear power plants, radioactive ions, etc. in the cooling water flowing through the nuclear power plant may adhere to oxides on the inside surfaces of the equipment and piping of the nuclear power plant, or is incorporated into the oxide when it is formed. As a result, equipment,
Since the surface dose rate of the pipes and pipes increases, maintenance and inspection work on equipment and pipes becomes difficult, and the time required for the work becomes significant.
従来よ〈実施されている金属表面から酸化物を除去する
方法は、特公昭５３−７３１号公報、及び特公昭５３−
２０２５２号公報に記載されているように、酸、錆化剤
、及び還元剤を混合した溶液を用いるものである。この
ような方法を用いた場合、除去作業時に、母材金属が腐
食していた。Conventional methods for removing oxides from metal surfaces are described in Japanese Patent Publication No. 53-731 and Japanese Patent Publication No. 53-731.
As described in Japanese Patent No. 20252, a solution containing an acid, a rusting agent, and a reducing agent is used. When such a method was used, the base metal was corroded during the removal work.
このような化学薬品を用いた場合、除去作業後プラント
の隙間構造部とが停滞部に化学薬品が残留することは不
可避である。このために、除去作業後でも母材金属が腐
食する危険性がある。When such chemicals are used, it is inevitable that the chemicals remain in the interstitial and stagnant parts of the plant after removal work. For this reason, there is a risk that the base metal will corrode even after the removal work.
原子力発電プラントでは、特に安全性が重要視されるた
めに除去作業後の残−留化学薬品による金属母材の腐食
は問題となる。従って、化学薬品を用いないで、放射性
酸化物除去方法が必要となる。In nuclear power plants, where safety is particularly important, corrosion of the metal base material by residual chemicals after removal work becomes a problem. Therefore, a method for removing radioactive oxides without using chemicals is needed.
本発明の目的は、酸化物除去時及び除去後において母材
金属の腐食損傷を抑制できるように化学薬品を用いるこ
となく酸化物を除去することにある。An object of the present invention is to remove oxides without using chemicals so that corrosion damage to the base metal can be suppressed during and after oxide removal.
酸化物の溶解現象は、金属−水系において、酸化物の熱
力学的安定性の概念と関連している。以下で鉄と水の系
を取シ上げて説明する。酸化物の熱力学的安定性を説明
する場合、第１図のプールベダイヤグラムが便利である
。第１図の電位の単位に表示されているＳＨＥは標準水
素電極電位を示す。以下で用いる電位の表示は、ＳＨＥ
で示す。The phenomenon of oxide dissolution is related to the concept of thermodynamic stability of oxides in metal-water systems. The iron and water system will be explained below. When explaining the thermodynamic stability of oxides, the Pourbaix diagram in FIG. 1 is useful. SHE displayed in the unit of potential in FIG. 1 indicates the standard hydrogen electrode potential. The display of potential used below is SHE
Indicated by
この図において領域１は金属鉄が熱力学的に安定な領域
である。領域２は鉄酸・化物であるＦ’ｅ、Ｏ。In this figure, region 1 is a region where metallic iron is thermodynamically stable. Region 2 is F'e, O, which is an iron oxide/oxide.
が熱力学的に安定な領域でアシ、領域３は鉄酸化物であ
るαｐｅ、Ｑ、が熱力学的に安定な状態になる領域であ
る。領域４はＦｅ”（オンが安定な領域であり１更に領
域５はｐ ｅ Ｓ ＋イオンが熱力学的に安定な領域で
ある。次に破線６０条件になると、１気圧の水素ガスが
発生する。又、破線７の条件になると、１気圧の酸素が
発生する。is a thermodynamically stable region, and region 3 is a region where αpe, Q, which is an iron oxide, is thermodynamically stable. Region 4 is a region where Fe" (on is stable, and region 5 is a region where p e S + ions are thermodynamically stable. Next, when the broken line 60 condition is reached, hydrogen gas of 1 atm is generated. .Furthermore, when the condition of the broken line 7 is reached, 1 atmosphere of oxygen is generated.
第１図かられかるように酸化物には安定な領域があり、
この領域のなかでは、酸化物は水に殆ど溶解しない。見
方を変えると、酸化物を熱力学的に不安定な状態にした
とき、酸化物の溶解が促進されることになる。As shown in Figure 1, oxides have stable regions,
Within this region, the oxide hardly dissolves in water. From a different perspective, when an oxide is made thermodynamically unstable, its dissolution is promoted.
通常の大気飽和の水を用いたとき、電位は、αＦｅ、０
．が安定となる領域３に落ち着く。本発明では、金属鉄
の腐食を抑制する目的をも考慮して、電位を卑の方向に
移動させ、酸化物を熱力学的に不安定な状態にすること
により酸化物を溶解させる。When using normal atmospheric saturated water, the potential is αFe, 0
．． It settles in region 3 where it is stable. In the present invention, taking into account the purpose of suppressing corrosion of metallic iron, the oxide is dissolved by moving the potential in a less noble direction and making the oxide thermodynamically unstable.
電位を卑の方向に移動させるだめの一つの方法として、
本発明では、溶存酸素濃度を下げることと水素ガスを溶
解させることの組み合せを用いる。One way to move the potential in the direction of base is to
The present invention uses a combination of lowering the dissolved oxygen concentration and dissolving hydrogen gas.
本発明で用いているように水を電解還元するとカフード
極上で次の反応
０２＋４６−＋４Ｈ” −＋２Ｈ２０
が起υ、溶存酸素濃度が減少する。When water is electrolytically reduced as used in the present invention, the following reaction 02+46-+4H"-+2H20 takes place on the top of the cup hood, and the dissolved oxygen concentration decreases.
本発明の効果を次に述べる実験により確認した。The effect of the present invention was confirmed by the experiment described below.
第２図に実験装置の概略を示す。本装置に関し、水を電
解還元する槽は、カソード室８とアノ、＝ド室９とにカ
チオン交換膜１０により仕切られている。各々の室には
、電極１１ＡおよびＩＩＢが挿入され、これらの電極に
は外部電源１２を接続する。Figure 2 shows an outline of the experimental apparatus. In this device, a tank for electrolytically reducing water is partitioned into a cathode chamber 8 and an anode chamber 9 by a cation exchange membrane 10. Electrodes 11A and IIB are inserted into each chamber, and an external power source 12 is connected to these electrodes.
カソード室８には、アルゴンボンベ１３−！たは水素ボ
ンベ１４から吹込口１６および１７を通してアルゴンガ
ス又は水素ガスを吹き込むことができる。In the cathode chamber 8, there is an argon cylinder 13-! Alternatively, argon gas or hydrogen gas can be blown from a hydrogen cylinder 14 through the blowing ports 16 and 17.
カソード室８には蒸留水を１を入れ、アノード室９には
、０．５Ｍ／ｌの蓚酸水溶液を１４入れる。The cathode chamber 8 is filled with 1 portion of distilled water, and the anode chamber 9 is filled with 0.5 M/l oxalic acid aqueous solution.
カソード室に入れる溶解実験用の酸化物ベレット１５と
して、市販のａｐｅ、Ｑ、及びＦ ｅ、０４粉末を直径
約１４ｙｍのペレット状に成形した後、約１２００Ｃで
約１時間焼成したものを用いた。As the oxide pellet 15 for dissolution experiments to be placed in the cathode chamber, commercially available ape, Q, and Fe, 04 powders were molded into pellets with a diameter of about 14 ym, and then fired at about 1200 C for about 1 hour. .
αＦｅ、０．、又はＦｅ３０ａ 酸化物から溶出した鉄
成分濃度は次のようにして求めた。まず、所定の時間、
カソード室８で酸化物を溶解させた後に、酸化物を除去
する。この残留液に濃塩酸を１０づ加える。原子吸光測
定装置を用いて、この水溶液を定量して、鉄成分濃度を
決めた。αFe, 0. , or Fe30a The concentration of the iron component eluted from the oxide was determined as follows. First, for a given time,
After the oxide is dissolved in the cathode chamber 8, the oxide is removed. Add 10 portions of concentrated hydrochloric acid to this residual solution. This aqueous solution was quantitatively determined using an atomic absorption spectrometer to determine the iron component concentration.
以上の装置及び手法を用いて０．２アンペアの電流を通
電しながら５時間αＦ ｅ ｔ Ｏ、とＦｅ５０＋を溶
解させたときの結果を表１に示す。Table 1 shows the results when αF e t O and Fe50+ were dissolved for 5 hours while applying a current of 0.2 ampere using the above apparatus and method.
表 １
この表１かられかるように、水の電解還元及び脱気を行
わないとき、並びにアルゴン脱気のみを行ない溶存酸素
濃度を約２００ｐｐｂに下げたときにαＦｅ２Ｏ３、及
びＦｅ３Ｏ４から溶出する鉄成分濃度は検出限度以下で
あった。Table 1 As can be seen from Table 1, iron components eluted from αFe2O3 and Fe3O4 when electrolytic reduction and deaeration of water are not performed, and when only argon deaeration is performed and the dissolved oxygen concentration is lowered to approximately 200 ppb. The concentration was below the detection limit.
ところが、アルゴンガスで脱気しながら０．２アンペア
で電解還元を実施したとき、αＦｅ２Ｏ３、及びＦｅ、
０４から溶出した鉄成分濃度は、各々０．８と０．１ｐ
Ｉ）ｍに増加した。更に水素ガスを吹き込みながら水を
電界還元した場合に、αＦｅ、ｏ３からの溶出鉄成分濃
度は５．６１）Ｉ）ｍに、又、Ｆｅ、Ｏ，からの溶出鉄
成分濃度は、ｏ、７ｐｐｍに増加した。However, when electrolytic reduction was carried out at 0.2 ampere while degassing with argon gas, αFe2O3 and Fe,
The concentrations of iron components eluted from 04 were 0.8 and 0.1p, respectively.
I) increased to m. Furthermore, when water is subjected to electric field reduction while blowing hydrogen gas, the concentration of iron components eluted from αFe, o3 becomes 5.61)I)m, and the concentration of iron components eluted from Fe, O, becomes o, 7 ppm. increased to
゛ 以上の水素ガスを吹き込みながら水を電解還元した
ときのαｐｅ２ｏ、から溶出する鉄成分濃度の時間変化
は第３図における一曲線Ａのようになった。゛ When water was electrolytically reduced while blowing in the above hydrogen gas, the time change in the concentration of iron components eluted from αpe2o was as shown by the curve A in FIG. 3.
この曲線Ａかられかるように、実験開始後、初期段階の
溶出速度は小さいけれども、時間の経過と共に溶出速度
は大きくなる。このことは溶出鉄イオンが酸化物の溶解
を促進していることを示す。As can be seen from this curve A, the elution rate is small in the initial stage after the start of the experiment, but the elution rate increases as time passes. This indicates that eluted iron ions promote the dissolution of oxides.
つ−！シ、溶出したＦ ｅ”イオン又はＦｅ■イオンが
カソード電極表面でｐ ｃ２４ｐ又はｐｅ に還元さ
れ、これらの還元された鉄成分がαＦｅ２Ｏ３の還元溶
解を促進する。このことは、事前に２ｐｐｍの鉄成分を
添加して溶解実験を行なって得だ溶出鉄成分濃度の時間
変化を表わす曲線Ｂから確認される。つまりこの場合曲
線Ｂから実験初期の段階から鉄成分溶出速度は大きい。Tsu-! The eluted Fe'' ions or Fe■ ions are reduced to p c24p or pe on the surface of the cathode electrode, and these reduced iron components promote the reductive dissolution of αFe2O3. This is confirmed from curve B, which represents the time change in the iron component concentration obtained by adding the components and performing a dissolution experiment.In other words, in this case, curve B shows that the rate of iron component elution is high from the initial stage of the experiment.
以上の結果から、本発明を用いると酸化物の溶解を促進
できることが実証された。The above results demonstrate that the use of the present invention can promote the dissolution of oxides.
次に本発明により腐食が抑制されることを説明する。こ
の場合腐食電位を測定するために、カソード室の蒸留水
に０．ＯＩＭ／ｌの濃度になるように硫酸ナトリウム（
Ｎ ａ ２８０４ ）を加えておく。水の電解還元及び
アルゴン脱気を行なわないとき炭素鋼の腐食電位は約＋
０．２ＶＣ／５ＨＥ）であった。次にアルゴンガスで脱
気して、溶存酸素濃度を約２００ｐｐｂに下げたとき、
腐食電位は約−〇、４ＶＣ／５ＨＥ）に下がった。この
電位は公知のように炭素鋼が全面腐食するときの電位で
ある（松林光男他、高純度水中における炭素鋼の腐食に
及ぼす溶存酸素の影響、防食技術２８巻、３２ ・頁
（１９７９年））。Next, it will be explained that corrosion is suppressed by the present invention. In this case, to measure the corrosion potential, add 0.0% to distilled water in the cathode chamber. Sodium sulfate (
Add Na 2804). The corrosion potential of carbon steel is approximately + without electrolytic reduction of water and argon degassing.
0.2VC/5HE). Next, when degassing with argon gas and reducing the dissolved oxygen concentration to about 200 ppb,
The corrosion potential decreased to approximately -0.4VC/5HE). As is well known, this potential is the potential at which carbon steel fully corrodes (Mitsuo Matsubayashi et al., Effect of Dissolved Oxygen on Corrosion of Carbon Steel in High Purity Water, Corrosion Prevention Technology Vol. 28, p. 32 (1979)) ).
ところが、水素ガスを吹き込みながら水を電解還元した
場合、腐食電位は、−０，５６Ｖ［／８ＨＥ）に下がっ
た。この電位は公知の炭素鋼のカソード防＾電位である
−０．５３ ’Ｖよりも卑な電位である。However, when water was electrolytically reduced while blowing hydrogen gas, the corrosion potential dropped to -0.56V [/8HE). This potential is less noble than -0.53'V, which is the cathode protection potential of known carbon steel.
つまりこのことは、炭素鋼の腐食が抑制されていること
を示す。In other words, this shows that corrosion of carbon steel is suppressed.
以上の結果から、水の電解還元と水素ガスの吹き込みを
組み合せると、金属母材の腐食を抑制しながら、表面の
酸化物を溶解除去することができる。更に、この方法で
は、化学薬品を用いていないので、残留化学薬品による
腐食の危険性は皆無である。つまり本発明は、原子力発
電プラントにおける機器、及び配管表面から放射性核種
を含有する酸化物を除去する方法として有望である。From the above results, when electrolytic reduction of water is combined with blowing hydrogen gas, oxides on the surface can be dissolved and removed while suppressing corrosion of the metal base material. Furthermore, since no chemicals are used in this method, there is no risk of corrosion due to residual chemicals. In other words, the present invention is promising as a method for removing oxides containing radionuclides from equipment and piping surfaces in nuclear power plants.
ＢＷＲ型原子力発電プラントにおける原子炉冷却材浄化
系（ＣＵＷ系）に本発明を適用するケースを第４図を用
いて説明する。ＣＵＷ系は、主に循環ポンプ１８、再生
熱交換器１９、非再生熱交換器２０、フィルタ２１、イ
オン交換樹脂を充填しだ脱塩器２２から構成されている
。ＣＵＷ系の配管２３の入口側は、原子炉圧力容器に接
続される再循環系配管に取付けられ、配管２３の出口側
は原子炉圧力容器に接続される給水配管に取付けられる
。A case in which the present invention is applied to a reactor coolant purification system (CUW system) in a BWR type nuclear power plant will be explained using FIG. 4. The CUW system mainly includes a circulation pump 18, a regenerative heat exchanger 19, a non-regenerative heat exchanger 20, a filter 21, and a demineralizer 22 filled with ion exchange resin. The inlet side of the CUW system piping 23 is attached to a recirculation system piping connected to the reactor pressure vessel, and the outlet side of the piping 23 is attached to a water supply piping connected to the reactor pressure vessel.
原子炉圧力容器内の冷却水は、再循環配管より配管２３
内に流入し、配管２３内を通って浄化された後、給水配
管を通って原子炉圧力容器内に戻される。この冷却水は
、配管２３内を通る間に、再生熱交換器１９および非再
生熱交換器２０で冷却された後、フィルタ２１および脱
塩器２２に送られ、そこで浄化される。脱塩器２２から
流出した冷却水は、再生熱交換器１９で加熱された後、
給水配管へと導かれる。Cooling water in the reactor pressure vessel is routed from recirculation piping to piping 23.
After passing through the piping 23 and being purified, it is returned to the reactor pressure vessel through the water supply piping. While passing through the pipe 23, this cooling water is cooled by the regenerative heat exchanger 19 and the non-regenerative heat exchanger 20, and then sent to the filter 21 and the demineralizer 22, where it is purified. The cooling water flowing out from the demineralizer 22 is heated in the regenerative heat exchanger 19, and then
You will be guided to the water supply pipes.
このＣＵＷ系の機器および配管内表面から放射性酸化物
を除去する場合には、次に挙げる設備を設置する。まず
ＣＵＷ系の配管２３の入口部と出口部に仮設配管２４を
設けて、冷却水を循環できるようにする。次に脱塩器２
２の出口部に仮設の電解装置２５、バイパス配管２６、
循壌ポンプ２７を設ける。電解装置２５は、第２図に示
すように、カチオン交換膜１０で仕切られたカソード室
８およびアノード室９を有している。更に効率よく酸化
物を除去するとき、水素ガス吹込み用タンク２８および
水素ボンベ２９を追加する。又このとき水素ガス発生源
として、水素ボンベ２９の代りに電解装置３０を用いて
も良い。この電解装置３０は電解装置２５と同様にカチ
オン交換膜に１リアノード室とカソード室に分離されて
いるが、水素ガスの発生効率を上げるためにカソード室
には濃厚な酸を入れておく。又必要に応じて、仮設のフ
ィルター３１およびイオン交換樹脂を有する脱塩器３２
を設置する。When removing radioactive oxides from the internal surfaces of CUW equipment and piping, the following equipment will be installed. First, temporary piping 24 is provided at the inlet and outlet of the CUW system piping 23 so that cooling water can be circulated. Next, desalinator 2
Temporary electrolysis device 25, bypass piping 26,
A circulation pump 27 is provided. As shown in FIG. 2, the electrolyzer 25 has a cathode chamber 8 and an anode chamber 9 separated by a cation exchange membrane 10. To remove oxides more efficiently, a hydrogen gas blowing tank 28 and a hydrogen cylinder 29 are added. Also, at this time, the electrolyzer 30 may be used as the hydrogen gas generation source instead of the hydrogen cylinder 29. Like the electrolyzer 25, this electrolyzer 30 is separated into one ryanode chamber and a cathode chamber by a cation exchange membrane, but a concentrated acid is placed in the cathode chamber in order to increase the efficiency of hydrogen gas generation. In addition, if necessary, a temporary filter 31 and a demineralizer 32 having an ion exchange resin may be installed.
Set up.
以上の設備を仮設した後に、バルブ３３Ａおよび３３Ｂ
を閉じ、循環ポンプ１８および２７を運転してＣＵＷ系
の配管２３内の冷却水を循環させる。パル２３３Ｃ，３
３Ｄおよび３３Ｅは閉じ、バルブ３３Ｆおよび３３Ｇは
開いている。配管２３内を流れる循環水にタンク２８内
で水素ガスを吹き込むと共に、電解装置２５にて循環水
を電解還元して、循環水を還元状態にする。この還元さ
れた循環水を用いて配管２３内壁に付着した放射性核種
を含有する酸化物を溶解除去する。次に溶出した成分を
フィルタ３１および脱塩器３２に導くことによってそこ
で除去する。After temporarily installing the above equipment, valves 33A and 33B
is closed, and the circulation pumps 18 and 27 are operated to circulate the cooling water in the CUW system piping 23. Pal 233C, 3
3D and 33E are closed and valves 33F and 33G are open. Hydrogen gas is blown into the circulating water flowing through the pipe 23 in the tank 28, and the circulating water is electrolytically reduced in the electrolyzer 25 to bring the circulating water into a reduced state. This reduced circulating water is used to dissolve and remove oxides containing radionuclides adhering to the inner wall of the pipe 23. The eluted components are then introduced into a filter 31 and a desalter 32 where they are removed.
次にＢＷＲ型原子力発電プラントにおける再循環系（Ｐ
ＬＲ系）に本発明を適用するケースを第５図に示す。Ｐ
ＬＲ系は、原子炉圧力容器３５内の冷却材を強制循環さ
せるために用いられたもので主に再循環ポンプ３６、再
循環系配管３７および弁３８Ａおよび３８Ｂから構成さ
れている。Next, the recirculation system (P
FIG. 5 shows a case in which the present invention is applied to the LR system. P
The LR system is used to forcefully circulate the coolant in the reactor pressure vessel 35, and is mainly composed of a recirculation pump 36, a recirculation system piping 37, and valves 38A and 38B.
この再循環ポンプ３Ｇおよび再循環系配管３７内に付着
した放射性酸化物を除く場合次の設備を仮設する。まず
再循環系配管３７の吹込側と吐出側とにバルブ３９Ａお
よび３９Ｂを有する配管３８を継ぐ。この配管３８に、
循環ポンプ３９、熱交換器４０、フィルタ４１、イオン
交換樹脂を有する脱塩器４２、水素ガス注入夕／り４３
および電解装置４４を設ける。水素ガス注入タンク４３
には水素ガスポンベ４５または水素ガス発生用電解装置
４６を接続する。電解装置４４の構成は、第２図のもの
と同一である。When removing radioactive oxides adhering to the recirculation pump 3G and the recirculation system piping 37, the following equipment will be temporarily installed. First, a pipe 38 having valves 39A and 39B is connected to the inlet side and the discharge side of the recirculation system pipe 37. In this pipe 38,
Circulation pump 39, heat exchanger 40, filter 41, demineralizer 42 with ion exchange resin, hydrogen gas injection tank 43
and an electrolysis device 44. Hydrogen gas injection tank 43
A hydrogen gas pump 45 or an electrolytic device 46 for hydrogen gas generation is connected to. The structure of the electrolyzer 44 is the same as that shown in FIG.
以上の設備を用い、ＣＵＷ系の場合と同様にノくルプ３
８Ａおよび３８Ｂを閉じてノ（ルブ３９Ａおよび３９Ｂ
を開き、循環ポンプ３９を駆動し、冷却水を循環させる
。水素ガスをタンク４３に導いて循環水に注入し、その
後、この循環水を電解装置４４にて電解還元する。この
循環水に溶出した成分をフィルタ４１および脱塩器４２
で除去する。Using the above equipment, Nokurupu 3 is installed in the same way as in the CUW system.
Close 8A and 38B and open (Lube 39A and 39B)
is opened, the circulation pump 39 is driven, and the cooling water is circulated. Hydrogen gas is introduced into the tank 43 and injected into the circulating water, and then the circulating water is electrolytically reduced in the electrolyzer 44. The components eluted into this circulating water are removed by a filter 41 and a demineralizer 42.
Remove with .
本発明によれば、化学薬品を用いることなく金属材料表
面の酸化物を効果的に除去できる。According to the present invention, oxides on the surface of a metal material can be effectively removed without using chemicals.
第１図はプールペダイヤグラム、第２図は本発明に用い
る電解装置の構造図、第３図は電解還元による溶出した
鉄分濃度の変化を示す特性図、第４図はＢＷＲＯＣＵＷ
系に適用した本発明の除染方法の系統図、第５図はＢＷ
ＲのＰＬＲ系に適用した本発明の他の実施例の系統図で
ある。Figure 1 is a Pourpe diagram, Figure 2 is a structural diagram of the electrolyzer used in the present invention, Figure 3 is a characteristic diagram showing changes in iron concentration eluted by electrolytic reduction, and Figure 4 is BWROCUW.
Systematic diagram of the decontamination method of the present invention applied to the system, Figure 5 is BW
FIG. 3 is a system diagram of another embodiment of the present invention applied to a PLR system of R.
Claims (1)
元した水に接触させることによシ還元溶解除去する金属
表面酸化物の除去方法。 ２、電解還元する水に、水素ガスを注入する請求の範囲
第１項記載の金属表面酸化物の除去方法。[Scope of Claims] 1. A method for removing oxides on a metal surface, in which oxides grown or attached to the surface of a base metal are brought into contact with electrolytically reduced water to reduce and dissolve them. 2. The method for removing metal surface oxides according to claim 1, wherein hydrogen gas is injected into the water to be electrolytically reduced.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13272281A JPS5837200A (en) | 1981-08-26 | 1981-08-26 | Removing method for oxide on metallic surface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13272281A JPS5837200A (en) | 1981-08-26 | 1981-08-26 | Removing method for oxide on metallic surface |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS5837200A true JPS5837200A (en) | 1983-03-04 |
Family
ID=15088047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13272281A Pending JPS5837200A (en) | 1981-08-26 | 1981-08-26 | Removing method for oxide on metallic surface |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5837200A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006314910A (en) * | 2005-05-12 | 2006-11-24 | Sato Kogyo Kk | Metallic work cleaning system, cleaning method and production method |
-
1981
- 1981-08-26 JP JP13272281A patent/JPS5837200A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006314910A (en) * | 2005-05-12 | 2006-11-24 | Sato Kogyo Kk | Metallic work cleaning system, cleaning method and production method |
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