• Title/Summary/Keyword: 원전해체폐기물

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Comparison of Compton Image Reconstruction Algorithms for Estimation of Internal Radioactivity Distribution in Concrete Waste During Decommissioning of Nuclear Power Plant (원전 해체 시 방사성 콘크리트 폐기물 내부 방사능 분포 예측을 위한 컴프턴 영상 재구성 방법의 비교)

  • Lee, Tae-Woong;Jo, Seong-Min;Yoon, Chang-Yeon;Kim, Nak-Jeom
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.2
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    • pp.217-225
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    • 2020

  • Concrete waste accounts for approximately 70~80% of the total waste generated during the decommissioning of nuclear power plants (NPPs). Based upon the concentration of each radionuclide, the concrete waste from the decommissioning can be used in the determination of the clearance threshold used to classify waste as radioactive. To reduce the cost of radioactive concrete waste disposal, it is important to perform decontamination before self-disposal or limited recycling. Therefore, it is necessary to estimate the internal radioactivity distribution of radioactive concrete waste to ensure effective decontamination. In this study, the performance metrics of various Compton reconstruction algorithms were compared in order to identify the best strategy to estimate the internal radioactivity distribution in concrete waste during the decommissioning of NPPs. Four reconstruction algorithms, namely, simple back-projection, filtered back-projection, maximum likelihood expectation maximization (MLEM), and energy-deconvolution MLEM (E-MLEM) were used as Compton reconstruction algorithms. Subsequently, the results obtained by using these various reconstruction algorithms were compared with one another and evaluated, using quantitative evaluation methods. The MLEM and E-MLEM reconstruction algorithms exhibited the best performance in maintaining a high image resolution and signal-to-noise ratio (SNR), respectively. The results of this study demonstrate the feasibility of using Compton images in the estimation of the internal radioactive distribution of concrete during the decommissioning of NPPs.

  • https://doi.org/10.7733/jnfcwt.2020.18.2.217 인용 PDF KSCI

Development of an Acceptance Criteria Implementation Flow Chart for verifying the Disposal Suitability of Radioactive Waste from Decommissioning of Nuclear Power Plants (원자력발전소 해체 방사성폐기물 처분 적합성 검증을 위한 인수기준 이행 흐름도 개발)

  • Kim, Chang Lak;Lee, Sun Kee;Kim, Heon;Sung, Suk Hyun;Park, Hae Soo;Kong, Chang Sig
    • Journal of the Korean Society of Systems Engineering
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    • v.17 no.1
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    • pp.65-75
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    • 2021

  • When the decommissioning of South Korea nuclear power plants is promoted in earnest with the permanent shutdown of Kori Unit 1 in 2017, a large amount of various types of radioactive waste will be generated. For minimal generation and safe management of decommissioning waste, the waste should be made by appropriate classification of the dismantling waste characteristics in accordance with physical, chemical and radiological characteristics to meet the acceptance criteria of disposal facilities. Replacing the preliminary inspection at the site for the compliance of the waste acceptance criteria (WAC) of medium and low-level radioactive waste with the generator's own radioactive waste certification program (WCP), from the perspective of disposal, the optimization of waste management at the national level contributes to the efficient availability of disposal, such as the processing of non-conforming radioactive wastes at the site. To this end, it is important to evaluate radioactivity in each system and area such as nuclear reactors before decommissioning is carried out in earnest, and the prior removal of harmful wastes is important. From waste collection to waste disposal, decommissioning waste should be managed at each stage in consideration of the acceptance criteria of disposal facilities to minimize the generation of non-conforming waste.

  • https://doi.org/10.14248/JKOSSE.2021.17.1.065 인용 PDF KSCI

Preparation of Radiological Environmental Impact Assessment for the Decommissioning of Nuclear Power Plant in Korea (국내 원전 해체시 방사선환경영향평가 방안)

  • Lee, Sang-Ho;Seo, Hyung-Woo;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.1
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    • pp.107-122
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    • 2018

  • Kori unit 1, the oldest commercial nuclear power plant in South Korea, was permanently shut down in June 2017. There are a lot of things to consider in decommissioning nuclear power plants, and one of them is the radiological environmental impact assessment. Performed to promote the health and safety of residents around the nuclear power plant, radiological environmental impact assessment aims to confirm that off-site radiological dose from radioactive material released from the facility does not exceed the regulatory criteria. There are three main parts of environmental impact assessment: pre-decommissioning environmental monitoring, environmental monitoring during decommissioning, and impact on nearby residents. At present, although the Korea Nuclear Safety Act stipulates that radiological environmental impact assessment resulting from decommissioning should be carried out, the details have not been specified. Therefore, this paper compares and analyzes guidelines for evaluation of radiological environmental impacts of nuclear power plants overseas, and presents a draft on the assessment of radiological dose resulting from decommissioning according to the Korean situation.

  • https://doi.org/10.7733/jnfcwt.2018.16.1.107 인용 PDF KSCI

Systems Engineering Approach for the Reuse of Metallic Waste From NPP Decommissioning and Dose Evaluation (금속해체 폐기물의 재활용을 위한 시스템엔지니어링 방법론 적용 및 피폭선량 평가)

  • Seo, Hyung-Woo;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.1
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    • pp.45-63
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    • 2017

  • The oldest commercial reactor in South Korea, Kori-1 Nuclear Power Plant (NPP), will be shut down in 2017. Proper treatment for decommissioning wastes is one of the key factors to decommission a plant successfully. Particularly important is the recycling of clearance level or very low level radioactively contaminated metallic wastes, which contributes to waste minimization and the reduction of disposal volume. The aim of this study is to introduce a conceptual design of a recycle system and to evaluate the doses incurred through defined work flows. The various architecture diagrams were organized to define operational procedures and tasks. Potential exposure scenarios were selected in accordance with the recycle system, and the doses were evaluated with the RESRAD-RECYCLE computer code. By using this tool, the important scenarios and radionuclides as well as impacts of radionuclide characteristics and partitioning factors are analyzed. Moreover, dose analysis can be used to provide information on the necessary decontamination, radiation protection process, and allowable concentration limits for exposure scenarios.

  • https://doi.org/10.7733/jnfcwt.2017.15.1.45 인용 PDF KSCI