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Corrosion Damage Characteristics of STS 304 for the Nuclear Power Plant with Chemical Decontamination Conditions in Permanganic and Oxalic Acid

과망간산과 옥살산 화학제염 공정 시 원전기기용 STS 304 의 부식 손상 특성

  • Han, Min-Su (Division of Marine Engineering, Mokpo National Maritime University) ;
  • Jung, Kwang-Hu (Division of Marine Engineering, Mokpo National Maritime University) ;
  • Yang, Ye-Jin (Division of Marine Engineering, Mokpo National Maritime University) ;
  • Park, Il-Cho (Division of Marine Engineering, Mokpo National Maritime University) ;
  • Kim, Ki-Chul (KEPCO Plant Service&Engineering Co., LTD) ;
  • Seo, Bum-Chul (KEPCO Plant Service&Engineering Co., LTD) ;
  • Park, Ju-Hyun (KEPCO Plant Service&Engineering Co., LTD) ;
  • Kim, Seong-Jong (Division of Marine Engineering, Mokpo National Maritime University)
  • Received : 2017.06.20
  • Accepted : 2017.08.17
  • Published : 2017.08.31

Abstract

This study was carried out with solution temperature variables of $75^{\circ}C$ and $90^{\circ}C$ for STS 304, which is a nuclear equipment material, in order to determine the corrosion damage behavior in chemical decontamination process using permanganic acid and oxalic acid. Then electrochemical polarization experiment, weight loss measurement, surface morphology observation and surface damage depth were measured every cycle of the decontamination process to analyze the degree of corrosion damage. As a result, the corrosion current density, weight loss, and surface damage increased as the decontamination process cycle increased, and the corrosion damage of STS 304 tended to increase. Few ${\mu}m$ pitting damage was observed on the surface observation. In 5 cycle, the elongated wormhole-type pitting damage appeared, leading to relatively large surface damage. However, there was no significant difference in the degree of surface damage resulting from the increase in the temperature of the chemical decontamination solution.

Keywords

References

  1. W.K. Kratzer, Decontamination and Decommissioning of Nuclear Facilities, Ed. M.M. Osterhout, Springer, New York (1980) 107-115.
  2. G.R. Choppin, et al., Literature Review of Dilute Chemical Decontamination Processes for Watercooled Nuclear Reactors, Report EPRI-NP-1033, Battelle Pacific Northwest Labs., Richland, (1979).
  3. H. Wille, H.O. Bertholdt, Water Chemistry of Nuclear Reactor Systems 5, ICE publishing, London (1989) 136-167.
  4. C.H. Jung, S.Y. Park, B.G. Ahn, B.J. Lee, W.Z. Oh, Decontamination of radioactive corrosion products by KAERI decontamination process, J. Korean Inst. Resour. Recycl., 8 (1999) 20-29.
  5. S.J. Kim, S.K. Jang, K.J. Kim, Evaluation of safety characteristic in chemical decontamination at extremely severe condition of stainless steels for coolant pump, Korean Soc. Mar. Environ. Saf., 12 (2006) 253-259.
  6. S.J. Kim, M.S. Han, J.I. Kim, K.J. Kim, Development of chemical decontamination process of stainless steel for reactor coolant pump, J. Kor. Inst. Surf. Eng., 40 (2007) 234-240. https://doi.org/10.5695/JKISE.2007.40.5.234
  7. S.J. Kim, J.I. Kim, K.J. Kim, Development of chemical decontamination process of stainless steel for reactor coolant pump (II), J. Kor. Inst. Surf. Eng., 40 (2007) 271-278. https://doi.org/10.5695/JKISE.2007.40.6.271
  8. S.J. Kim, M.S. Han, K.J. Kim, S.K. Jang, Evaluation on safety of stainless steels in chemical decontamination process with immersion type of reactor coolant pump for nuclear reactor, Corros. Sci. Technol., 10 (2011) 167-174.
  9. S.J. Kim, J.I. Kim, K.J. Kim, Evaluation of application possibility in chemical decontamination of materials for reactor coolant pump, J. Korean Soc. Mar. Eng., 31 (2007) 84-94. https://doi.org/10.5916/jkosme.2007.31.1.84
  10. E. Baumgartner, M.A. Blesa, H. Marinovich, A.J.G. Maroto, Heterogeneous electron transfer as a pathway in the dissolution of magnetite in oxalic acid solutions. Inorg. Chem., 22 (1983) 2224-2226. https://doi.org/10.1021/ic00158a002
  11. A. Cruickshank, Developing techniques for decontamination, Nucl. Eng. Int., 28 (1983) 41-44.