台灣在2025年即將面臨非核家園的政策實現，然而，核電廠除役並非是一件簡單的任務，依法規台電公司規劃的時程最長於二十年內完成，包含(1)除役過渡階段、(2)除役拆廠階段、(3)廠址最終狀態偵測階段與(4)廠址復原階段。

對電廠的廢棄金屬進行除污作業，包含了電化學除污、化學除污、生物除污、機械除污等方法，其中，電化學除污的好處是其消耗的化學品較少，可以深入管材的轉彎處，且消耗較化學除污少的化學品，速度也較單純浸泡式的化學除污快，在實際應用上非常有潛力。故本文的重點在於，在實驗室的小規模測試下，測量電化學除污的速率，與問題的提前發現。

本文的測試材料為碳鋼，在反應器機組中是常見的材料，值得一提的是，在放大試片的4cm*4cm實驗中，我們沒有觀察到明顯的不均勻問題，得到與小規模測試的2cm*2cm試片相近的除污效果。

最後，從除污後表面的SEM（掃描電子顯微鏡）圖像可以分析出，60w%磷酸電拋光後的表面比40w%磷酸電拋光後的表面具有更多的信息熵，也就是，60w%表面粗糙度更高，並且利用多元線性回歸和機器學習給出預測函數、CNN分類器。

In 2025, Taiwan is about to face the realization of the policy of non-nuclear homeland. However, the decommissioning of nuclear power plants is not an easy task. The timetable of Taiwan power company’s planning is as long as 20 years, including four stages: decommissioning transition stage, decommissioning demolition stage, field final state detection stage, and field recovery stage.

The decontamination of waste metals in power plants includes 4 methods: mechanical decontamination, biological decontamination, chemical decontamination, and electrochemical decontamination. Among them, electrochemical decontamination has the benefits of consume less chemicals, can penetrate deep into the turning of the pipe, and consume less chemicals than chemical decontamination, and the speed is faster than simple immersion chemical decontamination. It has great potential in practical application. Therefore, the focus of this article lies in the measurement of the rate of electrochemical decontamination and the early detection of problems under small-scale tests in the laboratory.

The test material in this paper is carbon steel, which is a common material in reactor units. It is worth mention that the uneven problem is not observed in the experiment of enlarging the test piece to 4cm*4cm and the decontamination rate measured is close to that of the 2cm*2cm small-scale test can be obtained.

Finally, from the SEM (Scanning Electron Microscope) image of the surface after decontamination, it can be analyzed that surface after 60 weight percent phosphoric acid electropolishing contains more information entropy than surface after 40 weight percent phosphoric acid electropolishing. Namely, 60 is rougher than 40. MLR and CNN is also used.

摘要 I
ABSTRACT II
誌謝 III
目錄 IV
表目錄 VII
圖目錄 VIII
第一章 前言 1
1.1 研究背景 1
1.2 研究動機 2
第二章 文獻回顧 3
2.1 核電廠待除污組件的材料簡介 3
2.1.1 放射性物質來源 5
2.1.2 金屬組件之氧化層結構 5
2.2 各類除污技術 7
2.2.1 化學除污 8
2.2.2 電化學除污 9
2.2.3 超音波除污 11
2.2.4 噴砂除污 11
2.2.5 乾冰噴射 11
2.2.6 電化學除污搭配超音波除污 12
2.3 孔蝕 13
2.4 沿晶腐蝕 14
第三章 實驗方法 16
3.1 試片製備 16
3.2 高溫氧化層 16
3.3 電鍍氧化層 17
3.4 表面分析 18
3.4.1 掃描式電子顯微鏡(Scanning Electron Microscope, SEM) 18
3.4.2 拉曼散射光譜(Laser Raman Spectroscopy, LRS) 20
3.5 電化學阻抗頻譜(ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY, EIS)與莫特-蕭特基分析(MOTT-SCHOTTKY ANALYSIS) 21
3.6 電化學除污 22
3.7 重量與厚度分析 25
第四章 結果與討論 27
4.1 碳鋼試片的氧化層橫截面SEM影像與拉曼分析 27
4.2 試片大小對碳鋼基材除污效率之影響 31
4.3 試片大小對碳鋼高溫氧化層除污效率之影響 32
4.4 試片大小對碳鋼電鍍氧化層除污效率之影響 34
4.5 試片大小對碳鋼複合氧化層除污效率之影響 35
4.6 磷酸濃度對2CM*2CM不同氧化層除污效率的影響 37
4.7 碳鋼2CM*2CM試片重量厚度變化結果種整理 41
4.8 磷酸濃度對4CM*4CM不同氧化層除污效率的影響 42
4.9 碳鋼4CM*4CM試片重量厚度變化結果種整理 47
4.10 相同電流密度改變大小對除污速率的影響 47
4.11 不同成份高溫氧化層對除污速率的影響 48
4.12 電鍍氧化層孔洞化對除污速率的影響 51
4.13 碳鋼2CM*2CM試片電化學除污後的表面形貌觀察 52
4.14 碳鋼4CM*4CM試片電化學除污後的表面形貌觀察 56
第五章 結論 62
第六章 未來建議方向 63
參考資料 64
附錄 68

1 Wagemans, C. The nuclear fission process. (1991).
2 游璦宇. 戰爭中的物理--希特勒破碎的原子彈夢與美國曼哈頓計畫. Chinese Physics 9, 1-16 (2008).
3 Ayres, G. The approach associated with the continued operation of the Calder Hall and Chapelcross nuclear power stations to 50 years. (1996).
4 志举 & 海容. 台湾十大工程掠影. 海洋世界, 45-45 (1999).
5 曾昱瑋 et al. 核能, 何能. (2015).
6 謝牧謙 et al. 福島事故後台日エネルギ: 政策の変換と原子力協力. Vol. 23 (國立臺灣大學出版中心, 2017).
7 余莓莓 & 黃琬珺. 核四公投的民主理想與現實困境. 臺灣國際研究季刊 9, 179-199 (2013).
8 林德福. 核能發電在台灣. 鑛冶: 中國鑛冶工程學會會刊 57, 7-10 (2013).
9 Chiao, L.-h. 符合世界經濟合作暨開發組織 (OECD)[國際核設施除役成本架構 (ISDC)] 之除役成本估算模式探討-以國內 CS 核電廠為例, National Central University, (2014).
10 胡毓青. 國內核能電廠除役方式評選之研究. (2008).
11 曾柏鈞. 核電廠除役時不銹鋼基材與異材銲件之電化學除污技術研究 碩士 thesis, 國立清華大學, (2020).
12 Roberts, J. A. Structural materials in nuclear power systems. (Springer Science & Business Media, 2013).
13 Gordon, B. M. Corrosion and Corrosion Control in Light Water Reactors. Jom 65, 1043-1056 (2013). https://doi.org:10.1007/s11837-013-0658-4
14 Dubey, V. & Kain, V. Oxidation Behavior of Carbon Steel: Effect of Formation Temperature and pH of the Environment. Journal of Materials Engineering and Performance 26, 5312-5322 (2017). https://doi.org:10.1007/s11665-017-3027-6
15 Xie, Y. & Zhang, J. Corrosion and deposition on the secondary circuit of steam generators. Journal of Nuclear Science and Technology 53, 1455-1466 (2016). https://doi.org:10.1080/00223131.2016.1152923
16 Lin, C.-C. & Hu, C.-C. Electropolishing of 304 stainless steel: Surface roughness control using experimental design strategies and a summarized electropolishing model. Electrochimica Acta 53, 3356-3363 (2008).
17 Han, W. & Fang, F. Fundamental aspects and recent developments in electropolishing. International Journal of Machine Tools and Manufacture 139, 1-23 (2019). https://doi.org:10.1016/j.ijmachtools.2019.01.001
18 Lu, C., Tang, Q., Chen, M., Zhou, X. & Zheng, Z. Study on ultrasonic electrochemical decontamination. Journal of Radioanalytical and Nuclear Chemistry 316, 1-7 (2018). https://doi.org:10.1007/s10967-018-5717-4
19 Szklarska-Smialowska, Z. Pitting corrosion of metals. National Association of Corrosion Engineers, 1440 South Creep Drive, Houston, Texas 77084, USA, 1986. 431 (1986).
20 Hoch, G., Staehle, R., Brown, B., Kruger, J. & Agrawal, A. (NACE International, Houston, 1974).
21 Pickering, H. W. The significance of the local electrode potential within pits, crevices and cracks. Corrosion Science 29, 325-341 (1989).
22 SUZUKI, T. & KITAMURA, Y. Critical potential for growth of localized corrosion of stainless steel in chloride media. Corrosion 28, 1-6 (1972).
23 Frankel, G. S. & Newman, R. C. in G. S. Frankel, and R. C. Newman, symposium held October, 1991 in Phoenix, Arizona,$ 45 member,$ 54 nonmember. Avail. from Electrochemical Society, PV-CFLC. Book.
24 Mayet, H. & Baroux, B. Critical Factors in Localized Corrosion II in PM Natishan, RG Kelly, GS Frankel, and R. Newman, Editors, PV, 95-15 (1995).
25 Revesz, A. & Kruger, J. Passivity of metals. RP Frankenthal and Jerome Kruger, Editors, 137 (1978).
26 Ambrose, J., Frankenthal, R. & Kruger, J. Passivity of metals. The electrochemical society. Princeton (NJ): Corrosion Monograph Series, 740 (1978).
27 王佳 & 曹楚南. 孔蚀发展期的电极阻抗频谱特征. 中国腐蚀与防护学报 9, 271-279 (1989).
28 曹楚南, 常晓元 & 林海潮. 孔蚀过程中的电化学噪声特征. 中国腐蚀与防护学报 9, 21-28 (1989).
29 Frankel, G. Pitting corrosion of metals: a review of the critical factors. Journal of the Electrochemical society 145, 2186 (1998).
30 Zhou, Y. & Yan, F. The relation between intergranular corrosion and electrochemical characteristic of carbon steel in carbonic. International Journal of Electrochemical Science 11, 3976-3986 (2016).
31 Tedmon, C., Vermilyea, D. & Rosolowski, J. Intergranular corrosion of austenitic stainless steel. Journal of the Electrochemical Society 118, 192 (1971).
32 Armijo, J. Intergranular corrosion of nonsensitized austenitic stainless steels. Corrosion 24, 24-30 (1968).
33 Wilson, F. Mechanism of intergranular corrosion of austenitic stainless steels—literature review. British Corrosion Journal 6, 100-108 (1971).
34 Matula, M. et al. Intergranular corrosion of AISI 316L steel. Materials characterization 46, 203-210 (2001).
35 Gao, Y., Zhang, C., Xiong, X., Zheng, Z. & Zhu, M. Intergranular corrosion susceptibility of a novel Super304H stainless steel. Engineering Failure Analysis 24, 26-32 (2012).
36 Pradhan, S., Bhuyan, P. & Mandal, S. Individual and synergistic influences of microstructural features on intergranular corrosion behavior in extra-low carbon type 304L austenitic stainless steel. Corrosion Science 139, 319-332 (2018).
37 Pardo, A. et al. Influence of Ti, C and N concentration on the intergranular corrosion behaviour of AISI 316Ti and 321 stainless steels. Acta Materialia 55, 2239-2251 (2007).
38 罗宏 & 龚敏. 奥氏体不锈钢的晶间腐蚀. 腐蚀科学与防护技术 18, 357-360 (2006).
39 廖啟民. 不銹鋼的沿晶腐蝕和應力腐蝕破裂. 防蝕工程 3, 4-19 (1989).
40 Küpper, J., Erhart, H. & Grabke, H.-J. Intergranular corrosion of iron-phosphorus alloys in nitrate solutions. Corrosion Science 21, 227-238 (1981).
41 Krautschick, H., Grabke, H. & Diekmann, W. The effect of phosphorus on the mechanism of intergranular stress corrosion cracking of mild steels in nitrate solutions. Corrosion science 28, 251-258 (1988).
42 Jeon, S.-H., Son, Y.-H., Choi, W.-I., Song, G. D. & Hur, D. H. Simulating Porous Magnetite Layer Deposited on Alloy 690TT Steam Generator Tubes. Materials 11 (2018).
43 Zhou, W., Apkarian, R., Wang, Z. L. & Joy, D. Fundamentals of scanning electron microscopy (SEM). Scanning Microscopy for Nanotechnology: Techniques and Applications, 1-40 (2007).
44 Inkson, B. J. in Materials characterization using nondestructive evaluation (NDE) methods 17-43 (Elsevier, 2016).
45 Nanakoudis, A. 什麼是SEM?淺談掃描式電子顯微鏡技術, 2019).
46 羅勝全. in 科學研習月刊 (2013).
47 Vehmaanperä, P., Sihvonen, T., Salmimies, R. & Häkkinen, A. Dissolution of Magnetite and Hematite in Mixtures of Oxalic and Nitric Acid: Mechanisms and Kinetics. Minerals 12 (2022).
48 Almeida, E., Pereira, D., Figueiredo, M. O., Lobo, V. M. M. & Morcillo, M. The influence of the interfacial conditions on rust conversion by phosphoric acid. Corrosion Science 39, 1561-1570 (1997). https://doi.org:https://doi.org/10.1016/S0010-938X(97)00058-9
49 Kothari, H. M. et al. Electrochemical deposition and characterization of Fe3O4 films produced by the reduction of Fe(III)-triethanolamine. Journal of Materials Research 21, 293-301 (2006). https://doi.org:10.1557/jmr.2006.0030