JPS6151758B2 - - Google Patents
Info
- Publication number
- JPS6151758B2 JPS6151758B2 JP53136694A JP13669478A JPS6151758B2 JP S6151758 B2 JPS6151758 B2 JP S6151758B2 JP 53136694 A JP53136694 A JP 53136694A JP 13669478 A JP13669478 A JP 13669478A JP S6151758 B2 JPS6151758 B2 JP S6151758B2
- Authority
- JP
- Japan
- Prior art keywords
- water supply
- supply system
- ferrous
- nuclear power
- power plant
- 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 48
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims description 25
- 229910001448 ferrous ion Inorganic materials 0.000 claims description 25
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 21
- 238000009835 boiling Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 10
- 238000005260 corrosion Methods 0.000 claims description 9
- 230000007797 corrosion Effects 0.000 claims description 9
- 229910021506 iron(II) hydroxide Inorganic materials 0.000 claims description 3
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical group [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 claims description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 16
- 239000010935 stainless steel Substances 0.000 description 11
- 229910001220 stainless steel Inorganic materials 0.000 description 11
- 238000010828 elution Methods 0.000 description 8
- 229910052759 nickel Inorganic materials 0.000 description 8
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 7
- 229910052804 chromium Inorganic materials 0.000 description 7
- 239000011651 chromium Substances 0.000 description 7
- 229910017052 cobalt Inorganic materials 0.000 description 7
- 239000010941 cobalt Substances 0.000 description 7
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 239000007800 oxidant agent Substances 0.000 description 4
- 230000002265 prevention Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 230000002285 radioactive effect Effects 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000005536 corrosion prevention Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- -1 iron ions Chemical class 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000002901 radioactive waste Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000000126 substance Substances 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
-
- 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
- Y02E30/30—Nuclear fission reactors
Landscapes
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Description
本発明は沸騰水型原子力発電プラントの腐食防
止方法に関し、特に該プラントの給水系構成材で
あるステンレス鋼の腐食防止方法に関する。
最近、沸騰水型原子力発電プラントにおいて
は、給水系の構成材である炭素鋼製配管の腐食を
防止するため、給水系に過酸化水素を添加する方
式が試みられている。しかしながら、実際のプラ
ントの給水系に過酸化水素を添加すると、給水加
熱器のステンレス鋼からクロム、ニツケル及びコ
バルト等が逆に溶出し、これらが原子炉中に持ち
込まれて放射化し、プラント構成材の表面に沈着
してプラント従事者の放射線被曝線量を増加させ
たり放射性廃棄物が増大する原因となり、プラン
ト運転上好ましくない問題がある。
本発明は、このような現状に鑑みてなされたも
のであり、その目的は、沸騰水型原子力発電プラ
ントの給水系構成材であるステンレス鋼の腐食防
止方法を提供することである。
本発明につき概説すれば、本発明は沸騰水型原
子力発電プラントの給水系に過酸化水素を添加し
て給水系構成材の腐食を防止するに当り、少なく
とも運転の初期において給水系の第一鉄イオン濃
度が約10ppb以上となる量の第一鉄イオンを給水
系中に添加することを特徴とするものである。
本発明者等は、沸騰水型原子力発電プラントの
給水系（以下単に給水系という）に過酸化水素を
添加する腐食防止方法において、給水系に第一鉄
イオンの所定量を添加することにより、ステンレ
ス鋼からクロム、ニツケル及びコバルト等が給水
系中に溶出するのを防止しうることを見出して本
発明に到達したものである。
本発明により給水系に第一鉄イオンを添加する
と、第一鉄イオンは給水系中の溶存酸素により酸
化され、ステンレス鋼の表面に酸化鉄の緻密な皮
膜が形成され、それにより上記金属の溶出防止が
可能となる。そして、一旦このような皮膜がステ
ンレス鋼の表面に形成されると、その後は、第一
鉄イオンの追加添加を行なわずに過酸化水素のみ
を添加しても上記金属の溶出は防止され、ただ、
プラントの定時点検等のため一旦プラントの運転
を停止し再起動する場合にのみ再度第一鉄イオン
の添加が必要となることが確認されている。
本発明において、給水系に第一鉄イオンを添加
する時期は特に限定されないが、望ましくは少な
くともプラント運転の初期に添加を行なうことに
より十分な効果が得られる。
本発明において、第一鉄イオンの必要な添加量
は、給水系中の第一鉄イオン濃度が約10ppb以上
となる量とし、この濃度になるように実機の一例
では、約12時間程度第一鉄イオンの添加を行なう
のが適当である。この濃度以下では長時間例えば
5ppbの濃度の場合100時間程度添加を続けても溶
出防止効果は認められず、前記皮膜の形成が全く
不十分であることが確認されている。この理由
は、実際のプラントの給水系においては、ステン
レス鋼の表面に緻密な酸化鉄の皮膜が形成される
過程で、皮膜の形成と剥離が同時に進行している
ため、ある程度以上の皮膜形成速度が達成される
ような第一鉄イオンの濃度が必要で、その濃度が
10ppb以上であることによるものと考えられる。
又、本発明において添加する第一鉄イオン物質
としては、水酸化第一鉄が適当であるが、スポン
ジ状鉄（還元鉄）を使用することもできる。
次に、本発明を沸騰水型原子力発電プラントの
給水系に使用した結果を図面を参照し、実施例と
して説明する。
実施例
添付図面は本実施例において使用した沸騰水型
原子力発電プラント（実機）の系統概略図であ
り、１は原子炉ボイラ、２は主蒸気管、３はター
ビン、４は発電機、５は復水器、６は復水ポン
プ、７は復水フイルタ、８は復水フイルタ下流配
管、９は復水脱塩器、１０は第一鉄イオン注入
点、１１は酸化剤注入点、１２は熱交換器、１３
は給水出口を示し、復水脱塩器９から給水出口１
３迄の管路を一般に給水系という。上記プラント
の通常運転時（運転操作の説明は省略する）に、
酸化剤注入点１１から給水系中に給水中の溶存酸
素が20ppbとなるように過酸化水素を添加し、そ
の添加を開始してから12時間後に、給水出口１３
で給水中に含まれるニツケル、クロム及びコバル
トの含量を測定した。なお、ニツケル及びクロム
は原子吸光法により、コバルトは無炎原子吸光法
により測定を行なつた。次に、過酸化水素水の添
加をそのまま続けて、第一鉄イオン注入点１０か
ら給水中の第一鉄イオン濃度が5ppbとなるよう
に水酸化第一鉄溶液を給水中に12時間添加し、第
一鉄イオンの添加を停止した後、給水出口１３で
給水中に含まれるニツケル、クロム及びコバルト
の含量を測定した。更に、添加する第一鉄イオン
の上記濃度を10、20及び50ppbに変化させて同様
の測定を行なつた。測定結果を下表に示す。
The present invention relates to a method for preventing corrosion of a boiling water nuclear power plant, and particularly to a method of preventing corrosion of stainless steel, which is a component of the water supply system of the plant. Recently, in boiling water nuclear power plants, attempts have been made to add hydrogen peroxide to the water supply system in order to prevent corrosion of carbon steel piping that is a component of the water supply system. However, when hydrogen peroxide is added to the water supply system of an actual plant, chromium, nickel, cobalt, etc. are eluted from the stainless steel of the feedwater heater, and these are carried into the reactor and become radioactive, causing plant components to become radioactive. It deposits on the surface of plants, increasing the radiation exposure of plant workers and increasing the amount of radioactive waste, which poses undesirable problems in plant operation. The present invention has been made in view of the current situation, and its purpose is to provide a method for preventing corrosion of stainless steel, which is a component of the water supply system of a boiling water nuclear power plant. To summarize the present invention, the present invention provides a method for preventing corrosion of the water supply system components by adding hydrogen peroxide to the water supply system of a boiling water nuclear power plant. It is characterized by adding ferrous ions to the water supply system in an amount such that the ion concentration is about 10 ppb or more. The present inventors have proposed a corrosion prevention method in which hydrogen peroxide is added to the water supply system (hereinafter simply referred to as the water supply system) of a boiling water nuclear power plant, by adding a predetermined amount of ferrous ions to the water supply system. The present invention was achieved by discovering that it is possible to prevent chromium, nickel, cobalt, etc. from leaching out of stainless steel into the water supply system. When ferrous ions are added to the water supply system according to the present invention, the ferrous ions are oxidized by dissolved oxygen in the water supply system, forming a dense film of iron oxide on the surface of the stainless steel, which causes the metal to elute. Prevention is possible. Once such a film is formed on the surface of stainless steel, even if only hydrogen peroxide is added without additional ferrous ions, the metals will not be leached out, but ,
It has been confirmed that it is necessary to add ferrous ions again only when the plant is temporarily stopped and restarted for periodic plant inspections, etc. In the present invention, the timing of adding ferrous ions to the water supply system is not particularly limited, but sufficient effects can be obtained by desirably adding them at least at the beginning of plant operation. In the present invention, the required amount of ferrous ions to be added is such that the ferrous ion concentration in the water supply system is about 10 ppb or more. It is appropriate to add iron ions. Below this concentration, for a long time, e.g.
In the case of a concentration of 5 ppb, no elution prevention effect was observed even after continued addition for about 100 hours, confirming that the formation of the film was completely insufficient. The reason for this is that in the actual water supply system of a plant, in the process of forming a dense iron oxide film on the surface of stainless steel, film formation and peeling occur simultaneously, so the film formation rate exceeds a certain level. A concentration of ferrous ions is required such that
This is thought to be due to the concentration being 10 ppb or more. Further, as the ferrous ion substance added in the present invention, ferrous hydroxide is suitable, but spongy iron (reduced iron) can also be used. Next, the results of using the present invention in a water supply system of a boiling water nuclear power plant will be described as an example with reference to the drawings. Example The attached drawing is a system schematic diagram of the boiling water nuclear power plant (actual plant) used in this example, where 1 is the reactor boiler, 2 is the main steam pipe, 3 is the turbine, 4 is the generator, and 5 is the system diagram. Condenser, 6 is a condensate pump, 7 is a condensate filter, 8 is condensate filter downstream piping, 9 is a condensate demineralizer, 10 is a ferrous ion injection point, 11 is an oxidizer injection point, 12 is heat exchanger, 13
indicates the water supply outlet, from the condensate demineralizer 9 to the water supply outlet 1
The pipes up to 3 are generally called the water supply system. During normal operation of the above plant (explanation of operation is omitted),
Hydrogen peroxide is added to the water supply system from the oxidizer injection point 11 so that the dissolved oxygen in the water supply becomes 20 ppb, and 12 hours after the start of the addition, the hydrogen peroxide is added to the water supply system from the oxidizer injection point 11.
The contents of nickel, chromium, and cobalt contained in the water supply were measured. Incidentally, nickel and chromium were measured by atomic absorption method, and cobalt was measured by flameless atomic absorption method. Next, the addition of the hydrogen peroxide solution was continued, and the ferrous hydroxide solution was added to the feed water for 12 hours from the ferrous ion injection point 10 so that the ferrous ion concentration in the feed water was 5 ppb. After stopping the addition of ferrous ions, the contents of nickel, chromium, and cobalt contained in the water supply were measured at the water supply outlet 13. Furthermore, similar measurements were carried out by changing the above concentration of ferrous ions to be added to 10, 20, and 50 ppb. The measurement results are shown in the table below.
【表】
表から明らかなように、添加した第一鉄イオン
の濃度が5ppbでは、ニツケル等の金属の溶出は
防止できず、10ppb以上となつてそれが可能とな
る。なお、上記第一鉄イオンの濃度を5ppbとし
添加時間を100時間に延長しても金属の溶出防止
効果はみられなかつた。又、10ppbの添加を行な
つた後、添加を停止し、過酸化水素のみの添加を
続けて運転を行なつたが、上記金属の溶出防止効
果は維持された。運転を停止し、再起動した場合
には、上記溶出効果は失なわれるが、再び所定濃
度に第一鉄イオンを添加することによりその効果
が発揮されることも確認された。以上の結果か
ら、第一鉄イオンを所定濃度に添加することによ
り、ステンレス鋼表面に緻密な酸化鉄の皮膜が形
成され、それによりステンレス鋼からのニツケ
ル、クロム及びコバルトの溶出が防止されること
及び添加濃度が10ppb付近に達しないとこの皮膜
の形成が不十分で溶出防止効果を発揮できないこ
とがわかる。
以上述べたとおり、本発明によれば、沸騰水型
原子力発電プラントの腐食防止に、過酸化水素と
共に所定濃度の第一鉄イオンを給水系中に添加す
ることにより、該プラントの給水系構成材の１種
であるステンレス鋼（給水加熱器等）からのニツ
ケル、クロム及びコバルトの溶出を防止すること
ができる。したがつて本発明は、放射線被曝によ
る公害防止その他の面で有用性の高いものであ
る。[Table] As is clear from the table, when the concentration of added ferrous ions is 5 ppb, the elution of metals such as nickel cannot be prevented, but it becomes possible when the concentration is 10 ppb or more. Note that even when the concentration of the ferrous ion was set at 5 ppb and the addition time was extended to 100 hours, no effect on preventing metal elution was observed. Further, after addition of 10 ppb, the addition was stopped and operation was continued while adding only hydrogen peroxide, but the above-mentioned metal elution prevention effect was maintained. It was also confirmed that when the operation was stopped and restarted, the elution effect was lost, but the effect was brought out by adding ferrous ions to a predetermined concentration again. From the above results, it is concluded that by adding ferrous ions at a specified concentration, a dense iron oxide film is formed on the stainless steel surface, thereby preventing the elution of nickel, chromium, and cobalt from the stainless steel. It can be seen that if the added concentration does not reach around 10 ppb, the formation of this film is insufficient and the elution prevention effect cannot be exhibited. As described above, according to the present invention, in order to prevent corrosion of a boiling water nuclear power plant, ferrous ions at a predetermined concentration are added to the water supply system together with hydrogen peroxide. It is possible to prevent the elution of nickel, chromium, and cobalt from stainless steel (feed water heaters, etc.), which is a type of stainless steel. Therefore, the present invention is highly useful in preventing pollution caused by radiation exposure and in other aspects.
図面は本発明の実施例において使用した沸騰水
型原子力発電プラントの系統概略図である。
１……原子炉ボイラ、２……主蒸気管、３……
タービン、４……発電機、５……復水器、６……
復水ポンプ、７……復水フイルタ、８……復水フ
イルタ下流配管、９……復水脱塩器、１０……第
一鉄イオン注入点、１１……酸化剤注入点、１２
……熱交換器、１３……給水出口。
The drawing is a schematic system diagram of a boiling water nuclear power plant used in an embodiment of the present invention. 1... Nuclear reactor boiler, 2... Main steam pipe, 3...
Turbine, 4... Generator, 5... Condenser, 6...
Condensate pump, 7... Condensate filter, 8... Condensate filter downstream piping, 9... Condensate demineralizer, 10... Ferrous ion injection point, 11... Oxidizer injection point, 12
...Heat exchanger, 13...Water supply outlet.
Claims (1)
化水素を添加して給水系構成材の腐食を防止する
に当り、少なくとも運転の初期において給水系の
第一鉄イオン濃度が約10ppb以上となる量の第一
鉄イオンを給水系中に添加することを特徴とする
沸騰水型原子力発電プラントの腐食防止方法。 ２ 第一鉄イオン源が水酸化第一鉄である特許請
求の範囲第１項記載の沸騰水型原子力発電プラン
トの腐食防止方法。[Claims] 1. When hydrogen peroxide is added to the water supply system of a boiling water nuclear power plant to prevent corrosion of the water supply system components, the ferrous ion concentration in the water supply system is reduced at least at the initial stage of operation. A method for preventing corrosion in a boiling water nuclear power plant, characterized by adding ferrous ions in an amount of approximately 10 ppb or more to the water supply system. 2. The method for preventing corrosion in a boiling water nuclear power plant according to claim 1, wherein the ferrous ion source is ferrous hydroxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13669478A JPS5563798A (en) | 1978-11-08 | 1978-11-08 | Corrosion protection method of bwr type power atomic plant |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13669478A JPS5563798A (en) | 1978-11-08 | 1978-11-08 | Corrosion protection method of bwr type power atomic plant |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5563798A JPS5563798A (en) | 1980-05-14 |
| JPS6151758B2 true JPS6151758B2 (en) | 1986-11-10 |
Family
ID=15181279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13669478A Granted JPS5563798A (en) | 1978-11-08 | 1978-11-08 | Corrosion protection method of bwr type power atomic plant |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5563798A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6078390A (en) * | 1983-10-05 | 1985-05-04 | 株式会社日立製作所 | Low radioactivity boiling-water type nuclear power plant |
| JPS6179194A (en) * | 1984-09-27 | 1986-04-22 | 株式会社東芝 | Reactor water feeder |
| JPH0666000B2 (en) * | 1984-12-21 | 1994-08-24 | 株式会社日立製作所 | Condensate purification system control method for boiling water nuclear power plant |
| JPS61240196A (en) * | 1985-04-18 | 1986-10-25 | 株式会社日立製作所 | Method and device for controlling water quality of boiling water reactor plant |
| JPH0631815B2 (en) * | 1985-04-23 | 1994-04-27 | 株式会社日立製作所 | Nuclear power plant water supply system |
| JPS62233796A (en) * | 1986-04-04 | 1987-10-14 | 株式会社日立製作所 | Method of reducing radioactivity of nuclear power plant |
| JP2523514B2 (en) * | 1986-07-16 | 1996-08-14 | 株式会社東芝 | Fuel assembly |
-
1978
- 1978-11-08 JP JP13669478A patent/JPS5563798A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5563798A (en) | 1980-05-14 |
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