JP2019168321A - Radiation source reduction metho of pressurized water type nuclear power plant component - Google Patents
Radiation source reduction metho of pressurized water type nuclear power plant component Download PDFInfo
- Publication number
- JP2019168321A JP2019168321A JP2018056014A JP2018056014A JP2019168321A JP 2019168321 A JP2019168321 A JP 2019168321A JP 2018056014 A JP2018056014 A JP 2018056014A JP 2018056014 A JP2018056014 A JP 2018056014A JP 2019168321 A JP2019168321 A JP 2019168321A
- Authority
- JP
- Japan
- Prior art keywords
- power plant
- nuclear power
- pressurized water
- cooling system
- primary cooling
- 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
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
- Chemical Treatment Of Metals (AREA)
Abstract
【課題】加圧水型原子力発電プラントにおける被ばくを更に低減する。【解決手段】加圧水型原子力発電プラントの一次冷却系の冷却材にＦｅ２＋を注入し、このＦｅ２＋を含む冷却材を前記一次冷却系の構成部材の表面に接触させることにより、この構成部材の表面にＦｅＣｒ２Ｏ４を含む酸化皮膜を生成し、その後、前記Ｆｅ２＋の注入を停止した状態で、前記一次冷却系の冷却材にＺｎ２＋を注入し、このＺｎ２＋を含む冷却材を前記構成部材の表面に接触させることにより、前記構成部材の表面にＺｎＣｒ２Ｏ４を含む酸化皮膜を生成する【選択図】なしAn exposure of a pressurized water nuclear power plant is further reduced. SOLUTION: Fe2 + is injected into a coolant of a primary cooling system of a pressurized water nuclear power plant, and a coolant containing the Fe2 + is brought into contact with a surface of the component of the primary cooling system, so that a surface of the component is formed on the surface of the component. An oxide film containing FeCr2O4 is generated, and then, while the injection of Fe2 + is stopped, Zn2 + is injected into the coolant of the primary cooling system, and the coolant containing Zn2 + is brought into contact with the surface of the constituent member. Produces an oxide film containing ZnCr2O4 on the surface of the component [selection]
Description
本発明は、原子力発電プラント構成部材の線源低減方法に関し、特に加圧水型原子力発電プラントの一次冷却系構成部材の線源低減方法に関する。 The present invention relates to a method for reducing the radiation source of a nuclear power plant component, and more particularly to a method for reducing the radiation source of a primary cooling system component of a pressurized water nuclear power plant.
従来、加圧水型原子力発電プラントの一次冷却系には、構成部材の線源低減による被ばく低減を目的として亜鉛注入が適用されている（例えば特許文献１）。
この亜鉛注入により被ばくは低減されるものの、原子力発電プラントにおいて被ばくはできる限り低減されることが好ましく、更なる被ばく低減が求められている。
Conventionally, zinc injection has been applied to a primary cooling system of a pressurized water nuclear power plant for the purpose of reducing exposure by reducing radiation sources of constituent members (for example, Patent Document 1).
Although exposure is reduced by this zinc injection, it is preferable to reduce exposure as much as possible in a nuclear power plant, and further reduction of exposure is required.
本発明が解決しようとする課題は、加圧水型原子力発電プラントにおける被ばくを更に低減することにある。 The problem to be solved by the present invention is to further reduce exposure in a pressurized water nuclear power plant.
この課題を解決するために本発明者らは、加圧水型原子力発電プラントの一次冷却系における蒸気発生器の伝熱管材料であるＮｉ基合金からのＮｉの溶出を抑制することに注目した。Ｎｉは炉心で放射性の５８Ｃｏに核変換し、この５８Ｃｏが一次冷却系構成部材の表面に沈着することで線源となり、被ばくの原因となるためである。
そこで本発明者らは、Ｎｉ基合金からのＮｉの溶出を抑制する観点から、既存の加圧水型原子力発電プラントの運転実績を含めて検討及び試験を重ね、その結果、鉄（Ｆｅ２＋）を注入後、亜鉛（Ｚｎ２＋）を注入することで、構成部材の表面にＺｎクロマイト皮膜（ＺｎＣｒ２Ｏ４）を含む厚くて緻密な酸化皮膜が形成され、これによりＮｉの溶出が抑制されることを見いだした。
In order to solve this problem, the present inventors have focused on suppressing elution of Ni from a Ni-based alloy which is a heat transfer tube material of a steam generator in a primary cooling system of a pressurized water nuclear power plant. This is because Ni transmutates to radioactive 58 Co in the core, and this 58 Co is deposited on the surface of the primary cooling system constituent member to become a radiation source and cause exposure.
Therefore, the present inventors have repeatedly studied and tested including the operation results of the existing pressurized water nuclear power plant from the viewpoint of suppressing the elution of Ni from the Ni-based alloy, and as a result, injected iron (Fe 2+ ). Thereafter, by injecting zinc (Zn 2+ ), a thick and dense oxide film containing a Zn chromite film (ZnCr 2 O 4 ) is formed on the surface of the constituent member, thereby suppressing the elution of Ni. I found it.
すなわち本発明によれば、次の線源低減方法が提供される。
加圧水型原子力発電プラントの一次冷却系の冷却材にＦｅ２＋を注入し、このＦｅ２＋を含む冷却材を前記一次冷却系の構成部材の表面に接触させることにより、この構成部材の表面にＦｅＣｒ２Ｏ４を含む酸化皮膜を生成する第一の工程と、
前記Ｆｅ２＋の注入を停止した状態で、前記一次冷却系の冷却材にＺｎ２＋を注入し、このＺｎ２＋を含む冷却材を前記構成部材の表面に接触させることにより、前記構成部材の表面にＺｎＣｒ２Ｏ４を含む酸化皮膜を生成する第二の工程とを含む、加圧水型原子力発電プラント構成部材の線源低減方法。
That is, according to the present invention, the following radiation source reduction method is provided.
Injecting Fe 2+ to the coolant in the primary cooling system of a pressurized water nuclear power plant, FeCr 2 coolant containing the Fe 2+ by contacting the surface of the primary cooling system components, the surface of the structural member A first step of producing an oxide film comprising O 4 ;
In a state where the injection of Fe 2+ is stopped, Zn 2+ is injected into the coolant of the primary cooling system, and the coolant containing this Zn 2+ is brought into contact with the surface of the component member, so that the surface of the component member is contacted. And a second step of producing an oxide film containing ZnCr 2 O 4 .
本発明によれば、加圧水型原子力発電プラント構成部材からのＮｉの溶出が抑制され、その結果、同構成部材の線源を更に低減でき、被ばくを更に低減できる。 According to this invention, the elution of Ni from a pressurized water nuclear power plant structural member is suppressed, As a result, the radiation source of the structural member can be further reduced, and the exposure can be further reduced.
本発明の線源低減方法は、加圧水型原子力発電プラント（以下「ＰＷＲ」という。）の一次冷却系（以下「ＰＷＲ一次冷却系」という。）の冷却材にＦｅ２＋を注入する第一の工程と、その後、このＰＷＲ一次冷却系の冷却材にＺｎ２＋を注入する第二の工程とを含む。このように、Ｆｅ２＋を注入後、Ｚｎ２＋を注入することで、詳細は後述するが、このＰＷＲ一次冷却系の構成部材（以下「ＰＷＲ構成部材」という。）の表面にＺｎクロマイト皮膜（ＺｎＣｒ２Ｏ４）を含む厚くて緻密な酸化皮膜が形成される。これにより、ＰＷＲ構成部材からのＮｉの溶出が抑制され、同構成部材の線源を更に低減でき、被ばくを更に低減できる。
なお、本発明においてＺｎ２＋の注入はＦｅ２＋の注入を停止した状態で実施する。Ｆｅ２＋とＺｎ２＋を同時に注入すると、ＰＷＲ構成部材の表面に形成される酸化皮膜の緻密性が損なわれるからである。
The radiation source reduction method of the present invention is a first step of injecting Fe 2+ into a coolant of a primary cooling system (hereinafter referred to as “PWR primary cooling system”) of a pressurized water nuclear power plant (hereinafter referred to as “PWR”). And then a second step of injecting Zn 2+ into the coolant of the PWR primary cooling system. In this way, by injecting Zn 2+ after injecting Fe 2+, as will be described in detail later, a Zn chromite film (ZnCr) is formed on the surface of the constituent member of this PWR primary cooling system (hereinafter referred to as “PWR constituent member”). A thick and dense oxide film containing 2 O 4 ) is formed. Thereby, the elution of Ni from the PWR constituent member is suppressed, the radiation source of the constituent member can be further reduced, and the exposure can be further reduced.
In the present invention, the Zn 2+ implantation is performed in a state where the Fe 2+ implantation is stopped. This is because if Fe 2+ and Zn 2+ are implanted at the same time, the denseness of the oxide film formed on the surface of the PWR component is impaired.
本発明において第一及び第二の工程は、ＰＷＲ起動時の高温停止状態到達時以降、すなわち原子炉起動前にＰＷＲ一次冷却系が運転中と同じ高温・高圧の状態に到達した時点以降に実施することが好ましい。このように、ＰＷＲ一次冷却系が運転中と同じ高温・高圧の状態で第一及び第二の工程を実施することで、ＰＷＲ構成部材の表面にＦｅＣｒ２Ｏ４を含む酸化皮膜（以下「Ｆｅクロマイト皮膜」という。）及びＺｎＣｒ２Ｏ４を含む酸化皮膜（以下「Ｚｎクロマイト皮膜」という。）を効果的に形成することができる。 In the present invention, the first and second steps are performed after reaching the high temperature shutdown state at the time of PWR start-up, that is, after the time when the PWR primary cooling system reaches the same high-temperature and high-pressure state as in operation before the reactor start-up. It is preferable to do. As described above, the PWR primary cooling system is subjected to the first and second steps at the same high temperature and high pressure as in operation, so that the surface of the PWR component member includes an oxide film (hereinafter referred to as “FeCr 2 O 4 ”). And an oxide film containing ZnCr 2 O 4 (hereinafter referred to as “Zn chromite film”) can be effectively formed.
ＰＷＲ構成部材とは、典型的にはＰＷＲ一次冷却系における蒸気発生器の伝熱管であり、このＰＷＲ構成部材は典型的にはＮｉ、Ｃｒ及びＦｅを含有するＮｉ基合金、より具体的にはインコネル（登録商標）よりなる。このようにＮｉ、Ｃｒ及びＦｅを含有するＮｉ基合金よりなるＰＷＲ構成部材に本発明を適用することで、Ｎｉの溶出抑制という本発明の効果が顕著になる。また、ＰＷＲ一次冷却系における蒸気発生器の伝熱管はＰＷＲ一次冷却系において最大の表面積を有しており、定期点検時等に作業者が接近する部位であるので、この伝熱管に本発明を適用することで本発明による被ばく低減効果が顕著になる。 A PWR component is typically a heat transfer tube of a steam generator in a PWR primary cooling system, and this PWR component is typically a Ni-based alloy containing Ni, Cr and Fe, more specifically Inconel (registered trademark). Thus, by applying the present invention to a PWR component made of a Ni-based alloy containing Ni, Cr and Fe, the effect of the present invention of suppressing the elution of Ni becomes remarkable. In addition, the heat transfer tube of the steam generator in the PWR primary cooling system has the largest surface area in the PWR primary cooling system, and is the part that the worker approaches during periodic inspections. Therefore, the present invention is applied to this heat transfer tube. By applying, the exposure reduction effect by this invention becomes remarkable.
本発明の効果を検証するために、以下の試験を実施した。
図１に試験の概要フローを示している。この試験では、ＰＷＲ一次冷却系における蒸気発生器の伝熱管材料として典型的なＴＴ６９０合金 (Thermal Treated690：60Ni-30Cr-10Fe）よりなる試験片を用い、本発明例ではＦｅ供給試験後、Ｚｎ供給試験を実施し、比較例ではブランク試験後、Ｚｎ供給試験を実施し、それぞれＺｎ供給試験終了後に試験片を取り出して試験片表面の酸化皮膜の形態分析を行った。また、それぞれＺｎ供給試験期間中にＮｉの溶出量を測定した。
なお、この試験の説明においては、Ｆｅ２＋、Ｚｎ２＋といったイオンをＦｅ、Ｚｎといった元素記号で表記する。
In order to verify the effect of the present invention, the following tests were conducted.
FIG. 1 shows an outline flow of the test. In this test, a test piece made of a typical TT690 alloy (Thermal Treated 690: 60Ni-30Cr-10Fe) is used as a heat transfer tube material of a steam generator in a PWR primary cooling system. In the comparative example, after the blank test in the comparative example, a Zn supply test was performed, and after completion of the Zn supply test, the specimen was taken out and the morphology of the oxide film on the surface of the specimen was analyzed. Further, the elution amount of Ni was measured during each Zn supply test period.
In the description of this test, ions such as Fe 2+ and Zn 2+ are represented by element symbols such as Fe and Zn.
この試験に使用した循環型オートクレーブ装置の概要構成を図２に示している。
この循環型オートクレーブ装置においてオートクレーブは一定温度（２９０℃）に設定し、このオートクレーブ内に試験片を治具に取り付けた状態で装荷した。試験水はＰＷＲを模擬した水質に調整後、試験系統に充填し、循環を行った。Ｚｎ、Ｃｏ、Ｆｅなどの添加元素については循環水タンクに連続注入し、循環水タンク及び器内水が一定濃度となるように管理した。試験片の腐食等に伴い器内水中に溶出する金属元素については、オートクレーブ出口側の、イオンペーパー及びメンブレンフィルタにて捕集した。
A schematic configuration of the circulation type autoclave used in this test is shown in FIG.
In this circulation type autoclave apparatus, the autoclave was set at a constant temperature (290 ° C.), and the test piece was loaded in a state where the test piece was attached to a jig. The test water was adjusted to water quality simulating PWR, filled in the test system, and circulated. Additive elements such as Zn, Co, and Fe were continuously injected into the circulating water tank and managed so that the circulating water tank and the in-vessel water had a constant concentration. The metal elements eluted in the water in the vessel due to corrosion of the test piece were collected by ion paper and membrane filter on the autoclave outlet side.
図１に示したＦｅ供給試験、ブランク試験及びＺｎ供給試験は、いずれも図２の循環型オートクレーブ装置により実施した。その具体的な試験条件を表１に示している。この表に示しているように、Ｆｅ供給試験、ブランク試験及びＺｎ供給試験はいずれも、ＰＷＲ一次冷却系における水質及び温度条件（ＰＷＲ条件）を模擬した試験条件にて実施した。 The Fe supply test, blank test, and Zn supply test shown in FIG. 1 were all carried out using the circulating autoclave apparatus shown in FIG. The specific test conditions are shown in Table 1. As shown in this table, the Fe supply test, blank test, and Zn supply test were all conducted under test conditions that simulated water quality and temperature conditions (PWR conditions) in the PWR primary cooling system.
すなわち、図２の循環型オートクレーブ装置においてオートクレーブ器内水は、ＰＷＲ条件を模擬した溶液とし、Ｂ源としてほう酸、Ｌｉ源として水酸化リチウムを添加した。また、溶存水素濃度（ＤＨ）を調整した。
そして、Ｆｅ供給試験では、Ｆｅ源として硫酸鉄（II）七水和物を添加し、Ｚｎ供給試験ではＺｎ源及びＣｏ源として酢酸亜鉛及び硝酸コバルトを添加した。
器内水調整後、循環水タンクから器内水を採取し、濃度を分析した。各元素の濃度についてはＩＣＰ−ＡＥＳ又はＩＣＰ−ＭＳにより分析し、所定濃度であることを確認した。
なお、Ｆｅ供給試験においては、Ｆｅ供給前に１００ｈｒのブランク試験を実施して、現実のＰＷＲ構成部材を模擬した予皮膜を形成した。
That is, in the circulating autoclave apparatus of FIG. 2, the water in the autoclave was a solution that simulated the PWR condition, and boric acid was added as the B source and lithium hydroxide was added as the Li source. The dissolved hydrogen concentration (DH) was adjusted.
In the Fe supply test, iron (II) sulfate heptahydrate was added as the Fe source, and in the Zn supply test, zinc acetate and cobalt nitrate were added as the Zn source and Co source.
After adjusting the internal water, the internal water was collected from the circulating water tank and the concentration was analyzed. The concentration of each element was analyzed by ICP-AES or ICP-MS and confirmed to be a predetermined concentration.
In the Fe supply test, a blank test of 100 hr was performed before supplying Fe to form a pre-coating film that simulated an actual PWR component.
Ｚｎ供給試験期間中にＮｉの溶出量を測定した。具体的には、試験時間１００ｈｒ、１０００ｈｒ、１５００ｈｒ、２０００ｈｒのタイミングでイオンペーパー及びメンブレンフィルタを交換、回収した。回収したイオンペーパー及びメンブレンフィルタの捕集成分は、ＩＣＰ−ＡＥＳ又はＩＣＰ−ＭＳにより分析し、Ｎｉ成分を定量した。 During the Zn supply test, the elution amount of Ni was measured. Specifically, the ion paper and the membrane filter were replaced and collected at the test times of 100 hr, 1000 hr, 1500 hr, and 2000 hr. The collected components of the collected ion paper and membrane filter were analyzed by ICP-AES or ICP-MS, and the Ni component was quantified.
図３に本発明例と比較例のＮｉ溶出量の測定結果を示している。Ｆｅ供給試験後にＺｎ供給試験を実施した本発明例では、Ｆｅ供給試験を実施しなかった比較例に比べ、Ｎｉ溶出量が継時的に少なくなった。すなわち、本発明の線源低減方法により、ＰＷＲ構成部材からのＮｉ溶出を抑制でき、その結果、同構成部材の線源を更に低減でき、被ばくを更に低減できることが確認された。 FIG. 3 shows the measurement results of the Ni elution amounts of the inventive example and the comparative example. In the present invention example in which the Zn supply test was performed after the Fe supply test, the amount of Ni elution was reduced over time as compared with the comparative example in which the Fe supply test was not performed. That is, it was confirmed that the elution of Ni from the PWR constituent member can be suppressed by the radiation source reducing method of the present invention, and as a result, the radiation source of the constituent member can be further reduced and the exposure can be further reduced.
次に、本発明例及び比較例についてそれぞれＺｎ供給試験終了後の試験片表面の酸化皮膜の形態分析を行った結果を説明する。 Next, the results of the morphological analysis of the oxide film on the surface of the test piece after completion of the Zn supply test for each of the inventive example and the comparative example will be described.
＜ＴＥＭによる断面観察＞
図４にＴＥＭによる断面観察像を示している。
本発明例では０．２μｍ程度の酸化皮膜が観察された。その酸化皮膜は、３０〜５０ｎｍ程度の層状の酸化皮膜の表面に７０〜１５０ｎｍ程度の酸化皮膜が析出している状況が観察された。
比較例でも０．２μｍ程度の酸化皮膜が観察された。その酸化皮膜は、１５〜３０ｎｍ程度の層状の酸化皮膜の表面に７０〜１５０ｎｍ程度の酸化皮膜が析出している状況が観察された。
すなわち、本発明例では、金属母材側に比較例に比べて厚い「層状の酸化皮膜」が観察された。
<Cross-section observation with TEM>
FIG. 4 shows a cross-sectional observation image by TEM.
In the present invention example, an oxide film of about 0.2 μm was observed. The oxide film was observed to have a thickness of about 70 to 150 nm deposited on the surface of a layered oxide film of about 30 to 50 nm.
Also in the comparative example, an oxide film of about 0.2 μm was observed. The oxide film was observed to have a thickness of about 70 to 150 nm deposited on the surface of a layered oxide film of about 15 to 30 nm.
That is, in the example of the present invention, a “layered oxide film” thicker than that of the comparative example was observed on the metal base material side.
＜ＴＥＭ／ＥＤＳ断面元素分布分析＞
図５にＴＥＭ／ＥＤＳによる断面マッピング像を示している。
本発明例では、金属母材層の表面にＣｒが層状に偏在している様子（Ｃｒ濃縮層）が明瞭に観察された。このＣｒ濃縮層にはＺｎが層状に偏在している様子が観察された。酸化皮膜の表層側にはＺｎが粒子状に偏在している様子が観察された。
比較例でも金属母材層の表面にＣｒが層状に偏在している様子（Ｃｒ濃縮層）が観察されたが、本発明例と比較して、Ｃｒ濃縮層は薄くやや不明瞭であった。また、比較例のＣｒ濃縮層には、Ｚｎが層状に偏在している様子は明瞭には観察されなかった。なお、比較例の酸化皮膜の表層側には本発明例と同様に、Ｚｎが粒子状に偏在している様子が観察された。
<TEM / EDS cross-section element distribution analysis>
FIG. 5 shows a cross-sectional mapping image by TEM / EDS.
In the example of the present invention, it was clearly observed that Cr was unevenly distributed on the surface of the metal base material layer (Cr concentrated layer). It was observed that Zn was unevenly distributed in the Cr concentrated layer. It was observed that Zn was unevenly distributed in the form of particles on the surface layer side of the oxide film.
In the comparative example, it was observed that Cr was unevenly distributed on the surface of the metal base material layer (Cr enriched layer), but the Cr enriched layer was thin and somewhat unclear compared to the inventive example. Further, it was not clearly observed that Zn was unevenly distributed in the Cr enriched layer of the comparative example. In addition, like the example of the present invention, it was observed that Zn was unevenly distributed in the form of particles on the surface layer side of the oxide film of the comparative example.
＜ＴＥＭ／ＥＤＳ深さ方向濃度プロファイル＞
図６にＴＥＭ／ＥＤＳによる深さ方向濃度プロファイルの結果を示している。
本発明例では、母材側から５０ｎｍ〜１００ｎｍ程度の酸化皮膜は、Ｃｒ組成が高い領域（Ｃｒ濃縮層）が観察され、Ｃｒ組成が６０〜７５％であった。同位置のＺｎ組成は１４〜１６％程度と高くなっており、Ｃｏ組成は１％程度であった。このＣｒ濃縮層と母材金属層の境界には、Ｎｉ組成が高い領域（Ｎｉ偏在層）が観察された。同位置のＮｉ組成は最大で６５％程度であり、金属母材であるＴＴ６９０の組成６０％より高い値であった。
比較例では、母材側から５０ｎｍ〜８０ｎｍ程度の酸化皮膜は、Ｃｒ組成が高い領域（Ｃｒ濃縮層）が観察され、Ｃｒ組成は６０〜８０％程度であった。同位置のＺｎ組成は２〜５％程度であり、Ｚｎ組成が低い傾向が観察された。また、同位置のＣｏ組成は１〜２％程度であった。このＣｒ濃縮層と母材金属層の境界には、Ｎｉ組成が高い領域（Ｎｉ偏在層）が観察された。同位置のＮｉ組成は最大で７５％程度であり、金属母材であるＴＴ６９０の組成６０％より高い値であった。
このように、本発明例では厚いＣｒ濃縮層が形成され、Ｃｒ濃縮層のＺｎ組成が高い傾向が観察された。
<TEM / EDS depth direction concentration profile>
FIG. 6 shows the result of the concentration profile in the depth direction by TEM / EDS.
In the example of the present invention, in the oxide film of about 50 nm to 100 nm from the base material side, a region having a high Cr composition (Cr enriched layer) was observed, and the Cr composition was 60 to 75%. The Zn composition at the same position was as high as about 14 to 16%, and the Co composition was about 1%. A region having a high Ni composition (Ni unevenly distributed layer) was observed at the boundary between the Cr enriched layer and the base metal layer. The Ni composition at the same position was about 65% at maximum, which was higher than the composition 60% of TT690, which is a metal base material.
In the comparative example, in the oxide film of about 50 nm to 80 nm from the base material side, a region having a high Cr composition (Cr enriched layer) was observed, and the Cr composition was about 60 to 80%. The Zn composition at the same position was about 2 to 5%, and a tendency for the Zn composition to be low was observed. The Co composition at the same position was about 1 to 2%. A region having a high Ni composition (Ni unevenly distributed layer) was observed at the boundary between the Cr enriched layer and the base metal layer. The Ni composition at the same position was about 75% at maximum, which was higher than the composition 60% of TT690, which is a metal base material.
Thus, in the example of this invention, the thick Cr concentrated layer was formed and the tendency for the Zn composition of a Cr concentrated layer to be high was observed.
＜ＴＥＭ電子線回折＞
図７に本発明例の酸化皮膜のＴＥＭ／ＥＤＳによる電子線回折の結果を示している。
同図（ａ）は図６等で示したＣｒ濃縮層の電子線回折結果であり、（Ｆｅ，Ｎｉ，Ｚｎ）Ｃｒ２Ｏ４（スピネル型酸化物）が同定された。
同図（ｂ）はこのＣｒ濃縮層より表層側の酸化皮膜の電子線回折結果であり、明瞭な電子線回折像は得られなかった。酸化物は、Ｃｒ、Ｆｅ、Ｎｉ、Ｚｎ、Ｃｏを含む非晶質であることが考えられた。
<TEM electron diffraction>
FIG. 7 shows the result of electron beam diffraction by TEM / EDS of the oxide film of the present invention.
FIG. 6A shows the electron diffraction results of the Cr enriched layer shown in FIG. 6 and the like, and (Fe, Ni, Zn) Cr 2 O 4 (spinel type oxide) was identified.
FIG. 4B shows the result of electron diffraction of the oxide film on the surface layer side from the Cr enriched layer, and a clear electron beam diffraction image was not obtained. It was considered that the oxide was amorphous including Cr, Fe, Ni, Zn, and Co.
以上の試験結果を整理すると以下のとおりである。
（１）本発明例ではＦｅ供給試験により、母材表面に厚いＣｒ濃縮層が形成された（図４〜６）。
（２）このＣｒ濃縮層はスピネル型酸化物が主であり、ＺｎはＺｎＣｒ２Ｏ４として取り込まれた（図５，７）。すなわち、Ｆｅ供給試験により形成されたＦｅＣｒ２Ｏ４に、Ｚｎ供給試験により供給されたＺｎが置換する形で取り込まれ、ＺｎＣｒ２Ｏ４を含む酸化皮膜（Ｃｒ濃縮層）が形成された。
（３）このＣｒ濃縮層が母材の表面を覆うに従い、継時的に母材からのＮｉ溶出抑制が機能した（図３）。
以上の評価から、Ｆｅを注入後、Ｚｎを注入することで、ＰＷＲ構成部材からのＮｉの溶出を抑制することが確認された。よって、本発明の有効性が証明された。
The above test results are summarized as follows.
(1) In the present invention example, a thick Cr concentrated layer was formed on the surface of the base material by the Fe supply test (FIGS. 4 to 6).
(2) This Cr enriched layer is mainly spinel oxide, and Zn was taken in as ZnCr 2 O 4 (FIGS. 5 and 7). That is, the Zn film supplied by the Zn supply test was incorporated into the FeCr 2 O 4 formed by the Fe supply test, and an oxide film (Cr enriched layer) containing ZnCr 2 O 4 was formed.
(3) As this Cr-enriched layer covered the surface of the base material, Ni elution suppression from the base material functioned over time (FIG. 3).
From the above evaluation, it was confirmed that by injecting Zn after injecting Fe, elution of Ni from the PWR component was suppressed. Therefore, the effectiveness of the present invention was proved.
Claims (4)
前記Ｆｅ２＋の注入を停止した状態で、前記一次冷却系の冷却材にＺｎ２＋を注入し、このＺｎ２＋を含む冷却材を前記構成部材の表面に接触させることにより、前記構成部材の表面にＺｎＣｒ２Ｏ４を含む酸化皮膜を生成する第二の工程とを含む、加圧水型原子力発電プラント構成部材の線源低減方法。 Injecting Fe 2+ to the coolant in the primary cooling system of a pressurized water nuclear power plant, FeCr 2 coolant containing the Fe 2+ by contacting the surface of the primary cooling system components, the surface of the structural member A first step of producing an oxide film comprising O 4 ;
In a state where the injection of Fe 2+ is stopped, Zn 2+ is injected into the coolant of the primary cooling system, and the coolant containing this Zn 2+ is brought into contact with the surface of the component member, so that the surface of the component member is contacted. And a second step of generating an oxide film containing ZnCr 2 O 4 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018056014A JP2019168321A (en) | 2018-03-23 | 2018-03-23 | Radiation source reduction metho of pressurized water type nuclear power plant component |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018056014A JP2019168321A (en) | 2018-03-23 | 2018-03-23 | Radiation source reduction metho of pressurized water type nuclear power plant component |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2019168321A true JP2019168321A (en) | 2019-10-03 |
Family
ID=68107239
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2018056014A Pending JP2019168321A (en) | 2018-03-23 | 2018-03-23 | Radiation source reduction metho of pressurized water type nuclear power plant component |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2019168321A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115874067A (en) * | 2023-01-04 | 2023-03-31 | 北京科技大学 | A method for separating vanadium and chromium from high chromium type vanadium slag |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4476047A (en) * | 1982-03-22 | 1984-10-09 | London Nuclear Limited | Process for treatment of oxide films prior to chemical cleaning |
| JP2008304381A (en) * | 2007-06-08 | 2008-12-18 | Hitachi-Ge Nuclear Energy Ltd | Method for suppressing radionuclide adhesion to nuclear plant components and ferrite film forming apparatus |
| JP2010043956A (en) * | 2008-08-12 | 2010-02-25 | Mitsubishi Heavy Ind Ltd | Method of operating nuclear plant |
| JP2015025688A (en) * | 2013-07-25 | 2015-02-05 | 日立Ｇｅニュークリア・エナジー株式会社 | Metal pouring method of nuclear power plant |
| JP2016164494A (en) * | 2015-03-06 | 2016-09-08 | 三菱重工業株式会社 | Surface processing method |
| JP2017122593A (en) * | 2016-01-05 | 2017-07-13 | 日立Ｇｅニュークリア・エナジー株式会社 | Method for suppressing adhesion of radionuclide and device for forming film on carbon steel pipe |
-
2018
- 2018-03-23 JP JP2018056014A patent/JP2019168321A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4476047A (en) * | 1982-03-22 | 1984-10-09 | London Nuclear Limited | Process for treatment of oxide films prior to chemical cleaning |
| JP2008304381A (en) * | 2007-06-08 | 2008-12-18 | Hitachi-Ge Nuclear Energy Ltd | Method for suppressing radionuclide adhesion to nuclear plant components and ferrite film forming apparatus |
| US20090316852A1 (en) * | 2007-06-08 | 2009-12-24 | Hideyuki Hosokawa | Method for suppressing deposit of radionuclide onto structure member composing nuclear power plant and ferrite film formation apparatus |
| JP2010043956A (en) * | 2008-08-12 | 2010-02-25 | Mitsubishi Heavy Ind Ltd | Method of operating nuclear plant |
| US20110075785A1 (en) * | 2008-08-12 | 2011-03-31 | Mitsubishi Heavy Industries, Ltd. | Method of operating nuclear plant |
| JP2015025688A (en) * | 2013-07-25 | 2015-02-05 | 日立Ｇｅニュークリア・エナジー株式会社 | Metal pouring method of nuclear power plant |
| JP2016164494A (en) * | 2015-03-06 | 2016-09-08 | 三菱重工業株式会社 | Surface processing method |
| JP2017122593A (en) * | 2016-01-05 | 2017-07-13 | 日立Ｇｅニュークリア・エナジー株式会社 | Method for suppressing adhesion of radionuclide and device for forming film on carbon steel pipe |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115874067A (en) * | 2023-01-04 | 2023-03-31 | 北京科技大学 | A method for separating vanadium and chromium from high chromium type vanadium slag |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Deng et al. | Effect of irradiation on corrosion of 304 nuclear grade stainless steel in simulated PWR primary water | |
| EP0736878B2 (en) | Crack growth mitigation method | |
| EP0181192A1 (en) | Method of reducing radioactivity in nuclear plant | |
| JP2016161466A (en) | Method for suppressing radionuclide adhesion to structural members of nuclear power plants | |
| JP2012247322A (en) | Method for forming platinum film on plant component | |
| JP2019168321A (en) | Radiation source reduction metho of pressurized water type nuclear power plant component | |
| JP2016102727A (en) | Method for preventing adhesion of radioactive nuclide to carbon steel member of nuclear power plant, and film formation device | |
| JP2018054538A (en) | Method for adhering noble metals to carbon steel members of nuclear power plant and method for suppressing radionuclide adhesion to carbon steel members of nuclear power plant | |
| JP5377147B2 (en) | Method of forming nickel ferrite film on carbon steel member | |
| US20100136215A1 (en) | Method for forming ferrite film onto surface of structural member composing plant, ferrite film formation apparatus and quartz crystal electrode apparatus | |
| Hanbury | The role of displacement damage in irradiation affected corrosion of 316L stainless steel | |
| JP4982465B2 (en) | Radioactivity decontamination method and radioactivity decontamination apparatus | |
| JP6751044B2 (en) | Method for depositing precious metal on carbon steel member of nuclear power plant, and method for suppressing deposition of radionuclide on carbon steel member of nuclear power plant | |
| CN117165932A (en) | Pre-oxidation method for primary loop system of boron-free nuclear reactor | |
| JP6322493B2 (en) | Method for suppressing radionuclide adhesion to carbon steel components in nuclear power plants | |
| JP3266485B2 (en) | Boiling water nuclear power plant, method of operating the same, and method of forming oxide film on wetted surface of its component | |
| JPS6295498A (en) | Nuclear power plant manufacturing method | |
| JP2017122593A (en) | Method for suppressing adhesion of radionuclide and device for forming film on carbon steel pipe | |
| JPH1048371A (en) | Nuclear power plant | |
| Sundell | Atomic scale degradation of zirconium alloys for nuclear applications | |
| Zhang et al. | Application Practice of Zinc Injection Technology in the Primary Circuit | |
| EP2833366B1 (en) | Radiation source reducing system and method for atomic power plant | |
| KR101584692B1 (en) | Method for manufacturing of Ni-base alloy tube and Ni-base alloy tube thereby | |
| Jeona et al. | Influences of Zn Concentration on the General Corrosion Behavior of Alloy 690TT in Simulated Primary Water of PWRs | |
| Perrin et al. | Influence of irradiation on stainless steel corrosion in PWR primary conditions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20210119 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20211111 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20220104 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20220628 |