JPH0438836B2 - - Google Patents
Info
- Publication number
- JPH0438836B2 JPH0438836B2 JP59173714A JP17371484A JPH0438836B2 JP H0438836 B2 JPH0438836 B2 JP H0438836B2 JP 59173714 A JP59173714 A JP 59173714A JP 17371484 A JP17371484 A JP 17371484A JP H0438836 B2 JPH0438836 B2 JP H0438836B2
- Authority
- JP
- Japan
- Prior art keywords
- dissolved oxygen
- water
- oxygen concentration
- corrosion
- piping
- 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 - Lifetime
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 51
- 238000005260 corrosion Methods 0.000 claims description 42
- 230000007797 corrosion Effects 0.000 claims description 42
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 37
- 239000001301 oxygen Substances 0.000 claims description 37
- 229910052760 oxygen Inorganic materials 0.000 claims description 37
- 239000007769 metal material Substances 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 18
- 229910000975 Carbon steel Inorganic materials 0.000 claims description 9
- 239000010962 carbon steel Substances 0.000 claims description 9
- 238000005536 corrosion prevention Methods 0.000 claims description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 6
- 239000003795 chemical substances by application Substances 0.000 claims description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- 238000007872 degassing Methods 0.000 claims description 4
- 229910021529 ammonia Inorganic materials 0.000 claims description 3
- 239000007789 gas Substances 0.000 claims description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 2
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 239000001257 hydrogen Substances 0.000 claims description 2
- 229910052739 hydrogen Inorganic materials 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 239000000498 cooling water Substances 0.000 claims 8
- 238000010248 power generation Methods 0.000 claims 4
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000001035 drying Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 230000004580 weight loss Effects 0.000 description 3
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 229910052938 sodium sulfate Inorganic materials 0.000 description 2
- 235000011152 sodium sulphate Nutrition 0.000 description 2
- 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 1
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- PWKWDCOTNGQLID-UHFFFAOYSA-N [N].[Ar] Chemical compound [N].[Ar] PWKWDCOTNGQLID-UHFFFAOYSA-N 0.000 description 1
- OLBVUFHMDRJKTK-UHFFFAOYSA-N [N].[O] Chemical compound [N].[O] OLBVUFHMDRJKTK-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 229910001651 emery Inorganic materials 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 235000013980 iron oxide Nutrition 0.000 description 1
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002901 radioactive waste Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
Landscapes
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Description
〔発明の利用分野〕
本発明は、酸素を溶存する水と金属材料とが接
する系において、接水金属材料の腐食を防止する
方法及び装置に関する。
〔発明の背景〕
酸素を溶存する水と金属材料とが接する系にお
いては接水金属材料が腐食される。腐食の程度は
溶存酸素濃度が高くなるほど著しく、特に水が酸
素を濃度約40ppb〜40ppm溶存する場合に、接水
金属材料に腐食が起り、その防食対策が必要とな
る。
特に、BWR（沸騰水型原子炉）プラントでは、
定期検査等の運転停止時においては、復水、給水
系配管が大気開放状態で５〜8ppmもの高い溶存
酸素濃度の水にさらされ、配管の金属材料、とり
わけ炭素鋼が著しく腐食される。腐食に伴い生じ
た腐食生成物（鉄酸化物を主体としたものでクラ
ツドと呼ばれる）は、プラント起動時に原子炉内
に持込まれて燃料棒に付着し、熱効率を低下させ
あるいは燃料棒を破損させるおそれがある。さら
に、燃料棒に付着したクラツドは放射化された後
剥離し、炉再循環系配管等に再付着して配管等の
表面線量率を増大させ、定期検査等の従事者に対
し放射能被曝量の増大を招く危険もある。これら
の理由から、BWRプラントの運転停止時におい
ては、復水、給水系配管の防食対策が重要な課題
となつている。
従来、酸素を溶存する水と金属材料とが接する
系、特にBWRプラントの運転停止時の防食に
は、ホツトドレンオフと呼ばれる水抜き乾燥法
が、一部のプラントにおいて採用されてきた。こ
の方法は、プラント運転停止後に給水が冷却しき
らないうちに水抜きし、余熱で配管表面を乾燥さ
せるものである。しかし、プラント構造には種々
のものがあり、すべてのプラントに適用できる方
法ではなく、水抜きに伴い生ずる多量の放射性廃
液の処理にも問題がある。さらに、この水抜き乾
燥法は操作も煩雑で、運転停止が短期の場合には
適当でない。
他の防食方法としては、火力プラントにおい
て、運転停止が短期間の場合にヒドラジン添加に
よる満水保管法が採用されている。BWRプラン
トにこの方法を適用すると、添加したヒドラジン
は後の起動時まで除去しなければならず、窒素ガ
スも脱気しなければならない等、後処理に問題が
ある。これらの方法をBWRプラントの防食に適
用することは困難である。
この問題に対して本発明者らは、水の比電導度
と流速とに注目した防食方法を先に提案した（特
開昭55−164081号）。この発明の要点は、水の比
電導度を0.5μS／cm以下に保ち、水を流動させる
ことであつた。
上記方法はそれなりに効果をあげたが、その後
の更に詳しい検討の結果、水の比電導度のある値
を境界として腐食挙動に差があることが見出され
た。
〔発明の効果〕
本発明の目的は、接水金属材料、特にBWRプ
ラントの停止時における接水金属材料の簡易な防
食方法及び装置を提供することである。
〔発明の概要〕
本発明の接水金属材料の防食方法は、酸素を溶
存する水と金属材料とが接する系において、水の
比電導度を検出し、その値により溶存酸素濃度あ
るいはPHを制御することを特徴とする。特に比
電導度が0.1μS／cmを境界として腐食挙動に差が
あることを発見したので、それを利用して防食す
るものである。
本発明を適用すべき系における水の溶存酸素濃
度は、金属材料が酸素溶存水に接して腐食され、
防食が問題となる範囲である。それは金属材料の
種類によつて異なる。具体的には約40ppb〜約
40ppmである。BWRプラントの運転停止時にお
ける復水、給水系配管は大気開放状態で５〜
8ppmの溶存酸素濃度の水に接することになるの
で、この配管の金属材料を防食するのに本発明は
特に好適である。
本発明において防食の対象となる金属材料とし
ては、酸素が溶存する水、特に溶存酸素濃度約
40ppb〜約40ppmの水に接して防食が問題となる
ものならばその種類を問わないが、特に例えば、
炭素鋼、低合金鋼、ステンレス鋼、銅、及びその
合金が挙げられる。BWRプラントの復水、給水
系配管の材料である炭素鋼は本発明により有効に
防食される。
BWRプラントの運転停止時は、復水、給水系
内の水の比電導度を低く保つと、系内の材料が防
食される。比電導度を低下させる手段は種々考え
られるが、通常は、例えば、粒状陽・陰両イオン
交換樹脂を充填した脱塩器に水を通せばよい。本
発明においては水の比電導度を検出し、0.1μS／
cm以下の場合には、溶存酸素濃度を約40ppb〜約
40ppmに保ち、接水金属材料の腐食速度を著しく
低減させ、有効に防食する。これに対し、脱塩器
性能等の問題からナトリウムリークなどにより比
電導度が0.1μS／cmを越えた場合には、溶存酸素
は腐食を促すので、脱気して望ましくは溶存酸素
濃度を40ppb以下に保つか、あるいはアルカリ剤
を注入し、PHを望ましくは7.5〜10に保ち防食す
る。
本発明方法を実施するには、電導度検出器、溶
存酸素濃度計、電導度検出器に連動する酸素注入
装置、及び脱気装置、あるいはアルカリ剤注入装
置とPH測定器の組み合せシステムが必要であ
る。なお、脱気は、窒素、アルゴン、水素の注入
により、また、PH調整はアンモニアの注入によ
り行う。
本発明の防食方法を実施する温度は通常20〜40
℃であり、時間は実施の態様に応じて適宜決めら
れる。
〔発明の実施例〕
次に本発明の実施例について説明する。
実施例 １
試験片浸漬による腐食減量の測定を行つた。
実験に供した炭素鋼は第１表の化学組成をもつ
SS41で、５×50×0.5mmの板状に加工したものを
用いた。試験片は表面を600番のエメリ紙で研磨
したのちトリクレンで脱脂処理し、浸漬直前まで
デシケータ内に保存した。
[Field of Application of the Invention] The present invention relates to a method and apparatus for preventing corrosion of a metal material in contact with water in a system where water containing dissolved oxygen contacts the metal material. [Background of the Invention] In a system where water containing dissolved oxygen comes into contact with a metal material, the metal material in contact with the water is corroded. The degree of corrosion becomes more significant as the dissolved oxygen concentration increases. Particularly when water contains dissolved oxygen at a concentration of approximately 40 ppb to 40 ppm, corrosion occurs in metal materials in contact with water, and corrosion prevention measures are required. Especially in BWR (boiling water reactor) plants,
During operational shutdowns such as periodic inspections, condensate and water supply system piping is exposed to water with a high dissolved oxygen concentration of 5 to 8 ppm in an open state, and the metal materials of the piping, especially carbon steel, are severely corroded. Corrosion products (commonly composed of iron oxides and called crud) generated due to corrosion are brought into the reactor at the time of plant startup and adhere to the fuel rods, reducing thermal efficiency or damaging the fuel rods. There is a risk. Furthermore, the crud attached to the fuel rods is activated and then peels off and re-attaches to the reactor recirculation system piping, etc., increasing the surface dose rate of the piping, etc. There is also the risk of causing an increase in For these reasons, corrosion prevention measures for condensate and water supply system piping are an important issue when BWR plants are shut down. Conventionally, a water draining drying method called hot drain-off has been used in some plants to prevent corrosion during shutdown of systems where metal materials come into contact with water containing dissolved oxygen, especially BWR plants. This method involves draining the water supply before it has completely cooled down after plant operation is stopped, and drying the piping surface using residual heat. However, there are various plant structures, and this method cannot be applied to all plants, and there are also problems in processing the large amount of radioactive waste liquid that is generated when water is drained. Furthermore, this draining and drying method is complicated to operate and is not suitable for short-term shutdowns. As another corrosion prevention method, a full-water storage method by adding hydrazine is used in thermal power plants when the plant is out of operation for a short period of time. When this method is applied to a BWR plant, there are problems with post-processing, such as the added hydrazine having to be removed until later during startup, and nitrogen gas also having to be degassed. It is difficult to apply these methods to corrosion protection in BWR plants. In response to this problem, the present inventors previously proposed a corrosion prevention method that focuses on the specific conductivity and flow velocity of water (Japanese Patent Application Laid-Open No. 164081/1981). The key point of this invention was to maintain the specific conductivity of water at 0.5 μS/cm or less and to make the water flow. Although the above method was somewhat effective, further detailed study revealed that there are differences in corrosion behavior around a certain value of the specific conductivity of water. [Effects of the Invention] An object of the present invention is to provide a simple method and apparatus for preventing corrosion of metal materials in contact with water, particularly when a BWR plant is stopped. [Summary of the Invention] The corrosion protection method for metal materials in contact with water of the present invention detects the specific conductivity of water in a system where water containing dissolved oxygen and metal materials come into contact, and controls the dissolved oxygen concentration or PH based on the detected value. It is characterized by In particular, we discovered that there is a difference in corrosion behavior when the specific conductivity reaches a boundary of 0.1 μS/cm, and we use this to prevent corrosion. The dissolved oxygen concentration in water in the system to which the present invention is applied is determined by corrosion of metal materials in contact with oxygen-dissolved water,
This is the range where corrosion protection becomes a problem. It depends on the type of metal material. Specifically, about 40ppb to approx.
It is 40ppm. When the BWR plant is shut down, the condensate and water supply system piping is left open to the atmosphere.
The present invention is particularly suitable for preventing corrosion of the metal material of this pipe, since it comes into contact with water with a dissolved oxygen concentration of 8 ppm. The metal material targeted for corrosion protection in the present invention is water containing dissolved oxygen, especially water with a dissolved oxygen concentration of about
It doesn't matter what type it is, as long as it comes in contact with water of 40ppb to about 40ppm and corrosion prevention is a problem, but in particular, for example,
Examples include carbon steel, low alloy steel, stainless steel, copper, and alloys thereof. The present invention effectively prevents corrosion of carbon steel, which is the material for condensate and water supply piping in BWR plants. When a BWR plant is shut down, keeping the specific conductivity of water in the condensate and water supply systems low will protect the materials in the system from corrosion. Various means for lowering the specific conductivity can be considered, but usually, for example, water may be passed through a demineralizer filled with granular cationic and anionic ion exchange resin. In the present invention, the specific conductivity of water is detected and is 0.1μS/
cm or less, reduce the dissolved oxygen concentration to about 40 ppb to approx.
Maintaining the level at 40ppm significantly reduces the corrosion rate of metal materials in contact with water, effectively preventing corrosion. On the other hand, if the specific conductivity exceeds 0.1 μS/cm due to sodium leak due to problems such as demineralizer performance, dissolved oxygen promotes corrosion, so it is desirable to reduce the dissolved oxygen concentration to 40 ppb by degassing. Either maintain the pH below or inject an alkaline agent to maintain the pH preferably between 7.5 and 10 to prevent corrosion. To carry out the method of the present invention, a combination system of a conductivity detector, a dissolved oxygen concentration meter, an oxygen injection device and a deaerator linked to the conductivity detector, or an alkaline agent injection device and a PH measuring device is required. be. Note that deaeration is performed by injecting nitrogen, argon, and hydrogen, and pH adjustment is performed by injecting ammonia. The temperature at which the corrosion prevention method of the present invention is carried out is usually between 20 and 40°C.
℃, and the time can be determined as appropriate depending on the implementation mode. [Embodiments of the Invention] Next, embodiments of the present invention will be described. Example 1 Corrosion loss was measured by immersing a test piece. The carbon steel used in the experiment had the chemical composition shown in Table 1.
SS41 was used, which was processed into a plate shape of 5 x 50 x 0.5 mm. The surface of the test piece was polished with No. 600 emery paper, degreased with Triclean, and stored in a desiccator until just before immersion.
【表】
浸漬した水の溶存酸素濃度は、酸素−窒素混合
ガスにより＜5ppb−8ppmに調整した。また、比
電導度は硫酸ナトリウム及び塩化ナトリウムを添
加し、＜0.1−10μS／cmに調整した。試験片は25h
浸漬し、腐食減量は浸漬前の重量と浸漬後に付着
した腐食生成物を除去したのちの重量の差で求め
た。なお、温度は25±２℃、流速は0.3cm／ｓで
あつた。
第１図は、純水中に不純物として硫酸ナトリウ
ムが存在し、水の比電導度が異なる場合に、溶存
酸素濃度が腐食減量に及ぼす影響を調べた結果を
示す図である。比電動度が0.1μS／cm以下では溶
存酸素濃度が40ppb−40ppmで腐食が抑制され
た。一方、0.1μS／cmを越えた場合には、溶存酸
素濃度を大気飽和状態の8ppmより減少させると、
腐食減量が減少し、特に40ppb以下にすると、効
果が顕著であつた。なお、脱気は、窒素アルゴン
等の不活性ガスあるいは水素ガスの系内への吹き
込み、あるいは真空脱気により達成される。
また、比電導度の調整を塩化ナトリウムで行つ
た場合にも同様の結果が得られた。
実施例 ２
第２表は溶存酸素濃度8ppm、比電動度1.0μS／
cmの水のPHを変化させた場合の炭素鋼の腐食減
量変化である。PHはアンモニアにより調整し
た。他の試験条件は実施例１と同じである。[Table] The dissolved oxygen concentration of the immersed water was adjusted to <5ppb-8ppm using an oxygen-nitrogen mixed gas. Further, the specific conductivity was adjusted to <0.1-10 μS/cm by adding sodium sulfate and sodium chloride. Test piece is 25h
The corrosion weight loss was determined by the difference between the weight before immersion and the weight after removing the corrosion products attached after immersion. The temperature was 25±2° C. and the flow rate was 0.3 cm/s. FIG. 1 is a diagram showing the results of investigating the influence of dissolved oxygen concentration on corrosion loss when sodium sulfate is present as an impurity in pure water and the specific conductivity of the water is different. When the specific conductivity was 0.1μS/cm or less, corrosion was suppressed at dissolved oxygen concentrations of 40ppb-40ppm. On the other hand, if it exceeds 0.1μS/cm, reducing the dissolved oxygen concentration below the atmospheric saturation level of 8ppm will result in
The corrosion weight loss was reduced, and the effect was particularly noticeable when the amount was lower than 40 ppb. Note that degassing is achieved by blowing an inert gas such as nitrogen argon or hydrogen gas into the system, or by vacuum degassing. Similar results were also obtained when the specific conductivity was adjusted using sodium chloride. Example 2 Table 2 shows dissolved oxygen concentration 8 ppm, specific electric power 1.0 μS/
This is the change in corrosion weight loss of carbon steel when the PH of water in cm is changed. PH was adjusted with ammonia. Other test conditions are the same as in Example 1.
本発明によれば、接水金属材料、特にBWRプ
ラントの停止時における接水金属材料の簡易な防
食方法及び装置が得られる。
According to the present invention, a simple method and apparatus for preventing corrosion of metal materials in contact with water, particularly metal materials in contact with water during shutdown of a BWR plant, can be obtained.
第１図は炭素鋼の腐食減量と溶存酸素濃度との
関係を示す図、第２図は炭素鋼の腐食電位の経時
変化を示す図、第３図は本発明による接水金属材
料の防食装置を備えたBWRプラントの系統概略
図である。
１……比電導度0.1μS／cm以下の曲線、２……
同0.15μS／cmの曲線、３……同0.30μS／cmの曲
線、４……同0.50μS／cmの曲線、５……同
1.00μS／cmの曲線、６……同10μS／cmの曲線、
７……PH7.0の曲線、８……PH7.5の曲線、９…
…PH8.4の曲線、１０……原子炉、１１……ター
ビン、１２……復水器、１３……復水脱塩器、１
４……復水低圧ポンプ、１５……給水再循環ライ
ン、１６……電導度検出器、１７……溶存酸素濃
度計、１８……注入装置、１９……PH測定器。
Fig. 1 is a diagram showing the relationship between corrosion loss of carbon steel and dissolved oxygen concentration, Fig. 2 is a diagram showing the change in corrosion potential of carbon steel over time, and Fig. 3 is a corrosion protection device for metal materials in contact with water according to the present invention. FIG. 1 is a schematic system diagram of a BWR plant equipped with 1...Curve with specific conductivity of 0.1μS/cm or less, 2...
Curve of 0.15μS/cm, 3...Curve of 0.30μS/cm, 4...Curve of 0.50μS/cm, 5...Curve of 0.50μS/cm
1.00μS/cm curve, 6... same 10μS/cm curve,
7...Curve of PH7.0, 8...Curve of PH7.5, 9...
...PH8.4 curve, 10... Nuclear reactor, 11... Turbine, 12... Condenser, 13... Condensate demineralizer, 1
4... Condensate low pressure pump, 15... Water supply recirculation line, 16... Conductivity detector, 17... Dissolved oxygen concentration meter, 18... Injection device, 19... PH measuring device.
Claims (1)
に接する冷却水の比電導度を計測し、比電導度が
0.1μS／cm以下の場合は溶存酸素濃度を40ppb〜
40ppmに保つ一方、0.1μS／cmを越える場合は脱
気により溶存酸素濃度を40pp上付以下に減少さ
せ、発電プラント停止期間中の配管を防食するこ
とを特徴とする接水金属材料の防食方法。 ２ 特許請求の範囲第１項において、窒素、アル
ゴン、水素のうち少なくとも一種を冷却水中に注
入して脱気することを特徴とする接水金属材料の
防食方法。 ３ BWR発電プラント復、給水系炭素鋼配管に
接する冷却水の比電導度を計測し、比電導度が
0.1μS／cm以下の場合は溶存酸素濃度を40ppb〜
40ppmに保つ一方、0.1μS／cmを越える場合はア
ルカリ剤の注入によりPHを7.5〜10に調節して、
発電プラント停止期間中の配管を防食することを
特徴とする接水金属材料の防食方法。 ４ 特許請求の範囲第３項において、注入するア
ルカリ剤がアンモニアであることを特徴とする接
水金属材料の防食方法。 ５ 原子炉とタービンと復水器と復水脱塩器とこ
れらを結ぶ配管とを含む発電プラントにおいて、
復水脱塩器下流の配管に、冷却水の比電導度を計
測する電導度検出器と、冷却水中の溶存酸素濃度
を測る溶存酸素濃度計と、それらの各パラメータ
測定値に応じて酸素あるいは溶存酸素脱気用ガス
を注入する装置とを配置してなり、比電導度が
0.1μS／cm以下の場合は溶存酸素濃度を40ppb〜
40ppmに保つ一方、0.1μS／cmを越える場合は脱
気用ガスの注入により溶存酸素濃度を40ppb以下
に減少させ、発電プラント停止期間中の配管を防
食することを特徴とする接水金属材料の防食装
置。 ６ 原子炉とタービンと復水器と復水脱塩器とこ
れらを結ぶ配管とを含む発電プラントにおいて、
復水脱塩器下流の配管に、冷却水の比電導度を計
測する電導度検出器と、冷却水中の溶存酸素濃度
を測る溶存酸素濃度計と、冷却水のPHを測る
PH測定器と、それらの各パラメータ測定値に応
じて酸素あるいはアルカリ剤を注入する装置とを
配置してなり、比電導度が0.1μS／cm以下の場合
は溶存酸素濃度を40ppb〜40ppmに保つ一方、
0.1μS／cmを越える場合はアルカリ剤の注入によ
りPHを7.5〜10に調節して、発電プラント停止期
間中の配管を防食することを特徴とする接水金属
材料の防食装置。[Claims] 1. The specific conductivity of the cooling water in contact with the carbon steel piping of the water supply system of a BWR power plant is measured, and the specific conductivity is
If it is 0.1 μS/cm or less, increase the dissolved oxygen concentration to 40 ppb or less.
A corrosion prevention method for metal materials in contact with water, which is characterized by maintaining the dissolved oxygen concentration at 40ppm, and reducing the dissolved oxygen concentration to below 40pp by degassing if it exceeds 0.1μS/cm, thereby preventing corrosion of piping during power plant shutdown periods. . 2. A method for preventing corrosion of metal materials in contact with water according to claim 1, characterized in that at least one of nitrogen, argon, and hydrogen is injected into cooling water to degas it. 3 Measure the specific conductivity of the cooling water in contact with the carbon steel piping of the BWR power generation plant and the water supply system, and determine the specific conductivity.
If it is 0.1 μS/cm or less, increase the dissolved oxygen concentration to 40 ppb or less.
While maintaining the pH at 40ppm, if it exceeds 0.1μS/cm, adjust the pH to 7.5-10 by injecting an alkaline agent.
A method for preventing corrosion of metal materials in contact with water, characterized by preventing corrosion of piping during a power generation plant shutdown period. 4. The method for preventing corrosion of metal materials in contact with water according to claim 3, characterized in that the alkaline agent to be injected is ammonia. 5. In a power generation plant including a nuclear reactor, a turbine, a condenser, a condensate desalinator, and piping connecting these,
In the piping downstream of the condensate demineralizer, there is a conductivity detector that measures the specific conductivity of the cooling water, and a dissolved oxygen meter that measures the dissolved oxygen concentration in the cooling water. A device for injecting dissolved oxygen degassing gas is installed, and the specific conductivity is
If it is 0.1 μS/cm or less, increase the dissolved oxygen concentration to 40 ppb or less.
40ppm, and if it exceeds 0.1μS/cm, the dissolved oxygen concentration is reduced to 40ppb or less by injecting deaeration gas, thereby preventing corrosion of piping during power plant shutdown periods. Corrosion protection equipment. 6 In a power generation plant including a nuclear reactor, a turbine, a condenser, a condensate demineralizer, and piping connecting these,
In the piping downstream of the condensate demineralizer, there is a conductivity detector that measures the specific conductivity of the cooling water, a dissolved oxygen concentration meter that measures the dissolved oxygen concentration in the cooling water, and a PH of the cooling water.
It is equipped with a PH measuring device and a device that injects oxygen or alkaline agent according to the measured values of each parameter, and maintains the dissolved oxygen concentration at 40 ppb to 40 ppm when the specific conductivity is 0.1 μS/cm or less. on the other hand,
A corrosion protection device for metal materials in contact with water, characterized in that if the pH exceeds 0.1 μS/cm, the pH is adjusted to 7.5 to 10 by injecting an alkaline agent to prevent corrosion of piping during a power plant shutdown period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59173714A JPS6152379A (en) | 1984-08-21 | 1984-08-21 | Method and device for corrosion prevention of wetting metallic material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59173714A JPS6152379A (en) | 1984-08-21 | 1984-08-21 | Method and device for corrosion prevention of wetting metallic material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6152379A JPS6152379A (en) | 1986-03-15 |
| JPH0438836B2 true JPH0438836B2 (en) | 1992-06-25 |
Family
ID=15965768
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59173714A Granted JPS6152379A (en) | 1984-08-21 | 1984-08-21 | Method and device for corrosion prevention of wetting metallic material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6152379A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6150175B2 (en) * | 2014-05-19 | 2017-06-21 | パナソニックＩｐマネジメント株式会社 | Superheated steam treatment method and apparatus |
| CN106499659B (en) * | 2016-11-28 | 2019-06-21 | 云南驰宏锌锗股份有限公司 | The protective device and guard method of anti-corrosion under a kind of centrifugal blower stoppage in transit state |
-
1984
- 1984-08-21 JP JP59173714A patent/JPS6152379A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6152379A (en) | 1986-03-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4820473A (en) | Method of reducing radioactivity in nuclear plant | |
| Hancock et al. | The inhibition of the corrosion of iron in neutral and alkaline solutions. I | |
| CA2926415C (en) | Ambient temperature decontamination of nuclear power plant component surfaces containing radionuclides in a metal oxide | |
| JPH0438836B2 (en) | ||
| Congleton et al. | Stress corrosion cracking of sensitized type 304 stainless steel in doped high-temperature water | |
| JPS6230269B2 (en) | ||
| RU2543573C1 (en) | Intracircuit passivation method of steel surfaces of fast neutron nuclear reactor | |
| JPH0566999B2 (en) | ||
| JPH0480357B2 (en) | ||
| JPS62182290A (en) | Method for preventing hydrogen embrittlement of member | |
| JPH0631815B2 (en) | Nuclear power plant water supply system | |
| JP2517723B2 (en) | How to prevent hydrogen cracking of metal parts | |
| RU2271410C2 (en) | Method for protecting power equipment against corrosion | |
| WO2001027932A1 (en) | Method for nuclear power plant decontamination | |
| JPS6296898A (en) | Power plant | |
| JPH02157503A (en) | Process of feed water treatment for steam power plant | |
| JPH0694209A (en) | Treatment of boiler feed water | |
| JPH0553400B2 (en) | ||
| JPS60103172A (en) | Method for preventing stress corrosion cracking in power plant | |
| JPH068913B2 (en) | Radioactivity reduction methods for nuclear power plants | |
| JPS58185778A (en) | Prevention of corrosion of carbon steel | |
| JPS642919B2 (en) | ||
| JPH03113397A (en) | Method for preventing stress corrosion cracking and hydrogen cracking of metallic member | |
| Prozorov | Behavior of pearlitic steels in oxygen containing water | |
| Shankar | Water chemistry in nuclear power reactors |