• Title/Summary/Keyword: high-level radioactive waste

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On the Research and Development for High Level Radioactive Waste Disposal in Korea (고준위 방사성폐기물 처분 기술개발 현황)

  • Lee, Young-Up
    • Economic and Environmental Geology
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    • v.28 no.3
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    • pp.279-286
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    • 1995
  • The amount of the high level radioactive wastes in Korea will be increased up to 14,297 MTU about 2010 year. Most of countries adopt the concept of deep burial repository in high level radioactive waste disposal. Because the high level radioactive wastes are very toxic in biosphere and to human, the data verifing its never return to the biosphere are requisite for the disposal. Presently, the evaluating techniques for the high level radioactive waste disposal are not fully developed. Therefore, in order to dispose the high level radioactive wastes in proper time the R & D of it is urged in our country. The R & D and/or the international joint research programme for the disposal of high level wastes have already been proceeded. In our country no plan for its disposal has been prepared. It is the time that the direction of the R & D is to be discused seriously. The R & D for the disposal of high level radioactive wastes in Korea is believed to be focused on developing the pecular techniques such as in situ characteristics of groundwater flowage, and change of properties of in situ rock mass at thermal effects.

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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.

Preliminary Assessment of Radiological Impact on the Domestic Railroad Transport of High Level Radioactive Waste (고준위 방사성폐기물의 국내철도운반에 관한 방사선영향 예비평가)

  • Seo, Myunghwan;Dho, Ho-Seog;Hong, Sung-Wook;Park, Jin Beak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.4
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    • pp.381-390
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    • 2017
  • In Korea, commercial nuclear power plants and research reactors have on-site storage systems for the spent nuclear fuel, but it is difficult to expand the facilities used for the storage systems. If decommissioning of nuclear power plants starts, an amount of high level radioactive waste will be generated. In this study, a radiological impact assessment of the railroad transport of high level radioactive waste was carried out considering radiation workers and the public, using the developed transport container as the transport package. The dose rates for workers and the public during the transport period were estimated, considering anticipated transport scenarios, and the results compared with the regulatory limit. A sensitivity analysis was also carried out by considering the different release ratios of the radioactive materials in the high level radioactive waste, and different distances between the transport container and workers during loading and unloading phases and while attaching another freight car. For all the anticipated transport scenarios, the radiological impacts for workers and the public met the regulatory limits.

Mathematical Modelling on THM Coupling in High-Level Radioactive Waste Repository (고준위 방사성폐기물 처분장에서의 THM 상호반응의 수학적 모델 개발)

  • 황용수;김진웅;강철형
    • Tunnel and Underground Space
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    • v.8 no.1
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    • pp.26-36
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    • 1998
  • To assess the groundwater flow near high-level radioactive waste repositories, it is important to understand the effect of coupling among thermal, hydraulic, and mechanical effects. In this paper, detailed mathematical approach to model the groundwater flow near the waste form surrounded by buffer, influenced by decay heat of radioactive waste along with stress change is developed. Two cases(1) before the full expansion of buffer and (2) after the full expansion of buffer are modelled. Based on the mathematical models in this paper, detailed numerical study shall be pursued later.

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DEPTH AND LAYOUT OPTIMIZATIONS OF A RADIOACTIVE WASTE REPOSITORY IN A DISCONTINUOUS ROCK MASS BASED ON A THERMOMECHANICAL MODEL

  • Kim, Jhin-Wung;Koh, Yong-Kwon;Bae, Dae-Seok;Choi, Jong-Won
    • Nuclear Engineering and Technology
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    • v.40 no.5
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    • pp.429-438
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    • 2008
  • The objective of the present study is the depth and layout optimizations of a single layer, high level radioactive waste repository in a discontinuous rock mass with special joint set arrangements. A single layer repository model, considering variations in the repository depths, pitches, and tunnel spacings, is used to analyze the thermomechanical interaction behavior. It is assumed that the repository is constructed in saturated granite with joints; the PWR spent fuel in a disposal canister is installed in a deposition drift which is then sealed with compacted bentonite; and the backfill material is filled in the repository tunnel. The decay heat generated by the high level radioactive wastes governs the thermomechanical behavior of the near field rock mass of the repository. The temperature and displacement behavior of the repository is influenced more by the pitch variations than the tunnel spacing and repository depth. However, the stress behavior is influenced more by the repository depth variations than the pitch and tunnel spacing. For the final selection of the tunnel spacing, pitch, and repository depth, other aspects such as the nuclide migration through a groundwater flow path, construction costs, operation costs, and so on should be considered.

Analysis on the concept design of the nuclear waste disposal site in foreign country (해외 방사성 폐기물 처분장 개념 설계 분석)

  • Seo, Kyoung-Won;Kim, Woong-Ku;Baek, Ki-Hyun;Jun, Seong-Keun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.791-800
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    • 2010
  • This paper presents the construction status and the conceptual designs of midium and high level radioactive waste disposal facilities from all around world. For the midium radioactive waste, a shallow disposal using trench or a deep depth disposal are adopted. However, these are rather focusing on the social and cultural point of view than the technical. Meanwhile, the high level radioactive waste is basically disposed in the deep underground. The corresponding ground conditions are usually dense and composed of sedimentary and crystalline rocks mainly with low permeability. A barrier system is made of canister which consists of copper, titanium, and tin. The inner and outer side of the canister are composed of different materials respectively.

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