• Title/Summary/Keyword: Nuclear waste storage

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Concepts of heat dissipation of a disposal canister and its computational analysis

  • Minseop Kim;Minsoo Lee;Jinseop Kim;Seok Yoon
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.4173-4180
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    • 2023

  • The stability of engineered barriers in high-level radioactive waste disposal systems can be influenced by the decay heat generated by the waste. This study focuses on the thermal analysis of various canister designs to effectively lower the maximum temperature of the engineered barrier. A numerical model was developed and employed to investigate the heat dissipation potential of copper rings placed across the buffer. Various canister designs incorporating copper rings were presented, and numerical analysis was performed to identify the design with the most significant temperature reduction effect. The results confirmed that the temperature of the buffer material was effectively lowered with an increase in the number of copper rings penetrating the buffer. Parametric studies were also conducted to analyze the impact of technical gaps, copper thickness, and collar height on the temperature reduction. The numerical model revealed that the presence of gaps between the components of the engineered barrier significantly increased the buffer temperature. Furthermore, the reduction in buffer temperature varied depending on the location of the gap and collar. The methods proposed in this study for reducing the buffer temperature hold promise for contributing to cost reduction in radioactive waste disposal.

  • https://doi.org/10.1016/j.net.2023.07.039 인용 PDF

Consideration on supplementary matters when preparing radioactive waste self-disposal (방사성폐기물 자체처분 작성시 보완사항에 관한 고찰)

  • Lee, Kyung-Jae;Park, Sung-woo;Park, Young-Jae;Park, In-Sik
    • The Korean Journal of Nuclear Medicine Technology
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    • v.26 no.1
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    • pp.15-26
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    • 2022

  • Purpose Recently, in the process of examining the self-disposal of radioactive waste by the Korea Institute of Nuclear Safety, it is difficult to reach the final approval process for self-disposal. In connection with this, we intend to increase the processing efficiency of self-disposal and strengthen safety by analyzing cases of recent supplementary matters. Materials and Methods From 2018 to 2021, we compare and review a supplementary requests that preparing the procedures and plans for the self-disposal of radioactive waste by 20 institutions. In this regard, based on the provisions of the Atomic Energy Safety Act, we derive a detailed proposals for the self-disposal of radioactive waste by arranging the review processing period calculation and supplementary requests that occurred during the review process. Results The representative supplementary requests of the Korea Institute of Nuclear Safety are the calculation of the storage period by type and nuclide of radioactive waste, the contents of the packaging container, the RASIS reporting method, the planned storage method for self-disposal, confirmation of the final disposal company, and the storage period of the waste filter Calculation, radioactive labeling, etc. And it is emphasized as important. Conclusion The expected effects of the guidelines reflecting the latest supplements include reduction of the time required for document preparation and increase of work processing efficiency, improvement of storage efficiency in the radioactive waste storage room, and economic cost reduction. If the radioactive waste self-disposal guideline presented in this study is applied to the field, it is thought that it will be helpful in improving the work efficiency of those who are experiencing difficulties.

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Design and Structural Safety Evaluation of Canister for Dry Storage System of PWR Spent Nuclear Fuels

  • Taehyung Na;Youngoh Lee;Taehyeon Kim;Donghee Lee
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.21 no.4
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    • pp.559-570
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    • 2023

  • The aim of this study is to ensure the structural integrity of a canister to be used in a dry storage system currently being developed in Korea. Based on burnup and cooling periods, the canister is designed with 24 bundles of spent nuclear fuel stored inside it. It is a cylindrical structure with a height of 4,890 mm, an internal diameter of 1,708 mm, and an inner length of 4,590 mm. The canister lid is fixed with multiple seals and welds to maintain its confinement boundary to prevent the leakage of radioactive waste. The canister is evaluated under different loads that may be generated under normal, off-normal, and accident conditions, and combinations of these loads are compared against the allowable stress thresholds to assess its structural integrity in accordance with NUREG-2215. The evaluation result shows that the stress intensities applied on the canister under normal, off-normal, and accident conditions are below the allowable stress thresholds, thus confirming its structural integrity.

  • https://doi.org/10.7733/jnfcwt.2023.034 인용 PDF

Repurposing a Spent Nuclear Fuel Cask for Disposal of Solid Intermediate Level Radioactive Waste From Decommissioning of a Nuclear Power Plant in Korea

  • Mah, Wonjune;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.3
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    • pp.365-369
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    • 2022

  • Operating and decommissioning nuclear power plants generates radioactive waste. This radioactive waste can be categorized into several different levels, for example, low, intermediate, and high, according to the regulations. Currently, low and intermediate-level waste are stored in conventional 200-liter drums to be disposed. However, in Korea, the disposal of intermediate-level radioactive waste is virtually impossible as there are no available facilities. Furthermore, large-sized intermediate-level radioactive waste, such as reactor internals from decommissioning, need to be segmented into smaller sizes so they can be adequately stored in the conventional drums. This segmentation process requires additional costs and also produces secondary waste. Therefore, this paper suggests repurposing the no-longer-used spent nuclear fuel casks. The casks are larger in size than the conventional drums, thus requiring less segmentation of waste. Furthermore, the safety requirements of the spent nuclear fuel casks are severer than those of the drums. Hence, repurposed spent nuclear fuel casks could better address potential risks such as dropping, submerging, or a fire. In addition, the spent nuclear fuel casks need to be disposed in compliance with the regulations for low level radioactive waste. This cost may be avoided by repurposing the casks.

  • https://doi.org/10.7733/jnfcwt.2022.024 인용 PDF KSCI