• 제목/요약/키워드: decontamination (HyBRID)

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원전 일차계통 HyBRID 제염공정 발생 폐액 내 불순물 제거 및 분해 (Removal and Decomposition of Impurities in Wastewater From the HyBRID Decontamination Process of the Primary System in a Nuclear Power Plant)

  • 은희철;정준영;박상윤;박정순;장나온;원휘준;심지형;김선병;서범경
    • 방사성폐기물학회지
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    • 제17권4호
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    • pp.429-435
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    • 2019

  • 원전 일차계통 HyBRID 제염공정에서 발생되는 제염폐액에는 황산이온과 방사성 핵종을 포함한 금속이온 및 발암성 물질의 하이드라진을 포함하고 있어 이를 안전한 수준으로 처리할 수 있는 기술개발이 필요하다. 본 연구에서는 모의 제염폐액내 황산 및 금속이온의 제거와 하이드라진의 분해시험을 실시하여 황산이온, 금속이온 및 하이드라진을 효과적으로 제거할 수 있는 HyBRID 제염폐액 처리공정을 도출하였으며, 1 L 규모에서의 반복실험과 Pilot 규모(300 L/batch)에서의 평가시험을 통해 도출한 HyBRID 제염폐액 처리공정의 성능 재현성과 적용성을 검증하였다.

  • https://doi.org/10.7733/jnfcwt.2019.17.4.429 인용 PDF KSCI

Electrochemical corrosion study on base metals used in nuclear power plants in the HyBRID process for chemical decontamination

  • Kim, Sung-Wook;Park, Sang-Yoon;Roh, Chang-Hyun;Shim, Ji-Hyung;Kim, Sun-Byeong
    • Nuclear Engineering and Technology
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    • 제54권6호
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    • pp.2329-2333
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    • 2022

  • Base metal corrosion forms a significant issue during the chemical decontamination of the primary coolant loop in nuclear power plants as it is directly related to the economic and safety viability of decommissioning. In this technical note, potentiodynamic evaluations of several base metals (304 stainless steel, SA106 Grade B carbon steel, and alloy 600) were performed to determine their corrosion behavior during the hydrazine (N2H4)-based reductive ion decontamination (HyBRID) process. The results suggested that N2H4 protected the surface of the base metals in the HyBRID solution, which is primarily composed of H2SO4. The corrosion resistance of the carbon steel was further improved through the addition of CuSO4 to the solution. The corrosion rate of carbon steel in the H2SO4-N2H4-CuSO4 solution was lower than that exhibited in an oxalic acid solution, a commonly used reaction medium during commercial decontamination processes. These results indicate the superiority of the HyBRID process with respect to the base metal stability.

  • https://doi.org/10.1016/j.net.2021.12.008 인용 PDF KSCI

Evaluation of dissolution characteristics of magnetite in an inorganic acidic solution for the PHWR system decontamination

  • Ayantika Banerjee ;Wangkyu Choi ;Byung-Seon Choi ;Sangyoon Park;Seon-Byeong Kim
    • Nuclear Engineering and Technology
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    • 제55권5호
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    • pp.1892-1900
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    • 2023

  • A protective oxide layer forms on the material surfaces of a Nuclear Power Plant during operation due to high temperature. These oxides can host radionuclides, the activated corrosion products of fission products, resulting in decommissioning workers' exposure. These deposited oxides are iron oxides such as Fe3O4, Fe2O3 and mixed ferrites such as nickel ferrites, chromium ferrites, and cobalt ferrites. Developing a new chemical decontamination technology for domestic CANDU-type reactors is challenging due to variations in oxide compositions from different structural materials in a Pressurized Water Reactor (PWR) system. The Korea Atomic Energy Research Institute (KAERI) has already developed a chemical decontamination process for PWRs called 'HyBRID' (Hydrazine-Based Reductive metal Ion Decontamination) that does not use organic acids or organic chelating agents at all. As the first step to developing a new chemical decontamination technology for the Pressurized Heavy Water Reactor (PHWR) system, we investigated magnetite dissolution behaviors in various HyBRID inorganic acidic solutions to assess their applicability to the PHWR reactor system, which forms a thicker oxide film.

  • https://doi.org/10.1016/j.net.2023.01.024 인용 PDF

High-temperature electrochemical corrosion behavior of SA106 Grade B carbon steel with corrosion inhibitors in HyBRID solution

  • Sung-Wook Kim;Sang-Yoon Park;Chang-Hyun Roh;Sun-Byeong Kim
    • Nuclear Engineering and Technology
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    • 제55권6호
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    • pp.2256-2262
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    • 2023

  • The electrochemical corrosion behaviors of SA106 Grade B (SA106B) carbon steel in H2SO44-N2H4 and H2SO4-N2H4-CuSO4 solutions at 95 ℃ have been investigated with the addition of commercial corrosion inhibitors (CI#30 and No. 570S), to determine the stability of SA106B in the hydrazine-based reductive metal ion decontamination (HyBRID) process. The potentiodynamic polarization experiment revealed that the corrosion inhibitors were capable of lowering the corrosion rate of SA106B in H2SO4-N2H4 solution. It was found that the corrosion inhibitors induced formation of fixed surface layer on the carbon steel upon the corrosion. This corrosion inhibition performance was reduced in the presence of CuSO4 in the solution owing to the chemical reactions between organic compounds in the corrosion inhibitors and CuSO4. CI#30 showed a better corrosion inhibition effect in the H2SO4-N2H4-CuSO4 solution. Although the corrosion inhibitors can provide better stability to SA106B in the HyBRID solution, their application should be carefully considered because it may result in reduced decontamination performance and increased secondary waste generation.

  • https://doi.org/10.1016/j.net.2023.03.008 인용 PDF

Equilibrium calculations for HyBRID decontamination of magnetite: Effect of raw amount of CuSO4 on Cu2O formation

  • Lee, Byung-Chul;Kim, Seon-Byeong;Moon, Jei-Kwon
    • Nuclear Engineering and Technology
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    • 제52권11호
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    • pp.2543-2551
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    • 2020

  • Calculations of chemical equilibrium for multicomponent aqueous systems of the HyBRID dissolution of magnetite were performed by using the HSC Chemistry. They were done by using a Pitzer-based aqueous solution model with the recipe of raw materials in experiments conducted at KAERI. The change in the amounts of species and ions and the pH values of the solution at equilibrium was observed as functions of temperature and raw amount of CuSO4. Precipitation of Cu2O occurred at a large amount of CuSO4 added to the solution, while no precipitation of Cu(OH)2 was found at any amounts of CuSO4. The E-pH diagrams for Cu were constructed at various Cu concentrations to provide the effect of the Cu concentration on the pH values at boundaries where the coexistence of Cu+ ion and Cu2O solid occurred. To prevent Cu+ ions from being precipitated to Cu2O, the raw amount of CuSO4 should be adjusted so that the pH value of the solution from the equilibrium calculation is less than that from the E-pH diagram. We provided guidelines for the raw amount of CuSO4 and the pH value of the solution, which prevent the formation of Cu2O precipitates in the HyBRID dissolution experiments for magnetite.

  • https://doi.org/10.1016/j.net.2020.04.012 인용 PDF KSCI