• Title/Summary/Keyword: Low level waste

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Review of the Acceptance Criteria of Very Low Level Radioactive Waste for the Disposal of Decommissioning Waste (극저준위 해체폐기물 처분을 위한 방사성폐기물 인수기준 분석)

  • Kim, Beomin;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.2
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    • pp.165-169
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    • 2014
  • In order to use the nuclear energy as the sustainable energy source, the safe and efficient management of radioactive wastes generated from the nuclear fuel cycle including NPP decommissioning is one of the most important factors. The establishment of acceptance criteria for very low level radioactive wastes generated from decommissioning of nuclear power plant in a large quantity is seemed to play a key role for developing a radioactive wastes disposal strategy as well as NPP decommissioning strategy. In this thesis, we want to review the acceptance criteria of low-and-intermediate-level radioactive wastes in this country through the analysis of other country's acceptance criteria.

A study on the effect of material impurity concentration on radioactive waste levels for plans for decommissioning of nuclear power plant

  • Gilyong Cha;Minhye Lee;Soonyoung Kim;Minchul Kim;Hyunmin Kim
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2489-2497
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    • 2023
  • Co and Eu impurities in the SSCs are nuclides that dominantly influence the neutron-induced radioactive inventory in metal and concrete radwastes (radioactive wastes) during NPP decommission. The impurity concentrations provided by NUREG/CR-3474 were used for the practical range of Co and Eu impurity concentrations to be applied to the code calculations. Metal structures near the core were evaluated to be ILW (intermediate-level waste) for the whole range of Co impurity concentration, so the boundary line between ILW and LLW (low-level waste) has no change for the whole concentration range provided by NUREG/CR-3474. Also, the boundary line between VLLW (very low-level waste) and CW (clearance waste) in the concrete shield could alter a little depending on the Eu impurity concentration within the range provided by NUREG/CR-3474. From this work, it is found that the concentration of material impurities of SSCs gives no critical impact on determining radwaste levels.

Safety Assessment for the Landfill Disposal of Decommissioning Waste Solidified by Magnesium Potassium Phosphate Cement

  • Jeong, Jongtae;Baik, Min-Hoon;Lee, Jae-Kwang;Pyo, Jae-Young;Um, Wooyong;Heo, Jong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.1
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    • pp.13-22
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    • 2022
  • The decommissioning of a nuclear power plant generates large amounts of radioactive waste, which is of several types. Radioactive concrete powder is classified as low-level waste, which can be disposed of in a landfill. However, its safe disposal in a landfill requires that it be immobilized by solidification using cement. Herein, a safety assessment on the disposal of solidified radioactive concrete powder waste in a conceptual landfill site is performed using RESRAD. Furthermore, sensitivity analyses of certain selected input parameters are conducted to investigate their impact on exposure doses. The exposure doses are estimated, and the relative impact of each pathway on them during the disposal of this waste is assessed. The results of this study can be used to obtain information for designing a landfill site for the safe disposal of low-level radioactive waste generated from the decommissioning of a nuclear power plant.

The Study on the Way of Radioactive Waste Disposal in China

  • Keyan Teng;Hao Peng;Caixia Lv;Han Wu
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.4
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    • pp.533-540
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    • 2022
  • Because of the massive development of nuclear power plants in China in recent years, China is facing the challenge of radioactive waste disposal. China has established complete regulatory requirements for radioactive waste disposal, but it also has encountered problems and challenges in low-level radioactive waste disposal in terms of management, selection of disposal facility sites, and implementation of a site selection plan. Three low-level radioactive waste disposal facilities that have been operated in China are described, and their activity limits, locations, and capacities are also outlined. The connotations of "regional" and "centralized" disposal policies are discussed in light of the characteristics of the radioactive waste. The characteristics and advantages of the regional and centralized disposal policies are compared. It is concluded that the regional disposal policy adopted in 1992 can no longer meet the current disposal needs, and China should adopt a combination of the two disposal policies to solve the problem of radioactive waste disposal.

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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Mechanical Properties of Plastic Waste/Cellulose Waste Composites (폐플라스틱/폐섬유소 복합체의 기계적 물성)

  • Hong, Young-Keun
    • Elastomers and Composites
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    • v.38 no.1
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    • pp.19-26
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    • 2003
  • Mechanical properties of the commingled waste plastics filled with waste newspaper were studied. To improve adhesion at the interface, abietic acid was used. Tensile strength increased with fiber concentration. However the abietic acid did not have any influence on the strength. Tensile strain and impact strength as well decreased with increasing fiber level in the composite, but the abietic acid at low level of concentration with low level of fiber dramatically improved both properties. The reason seemed to be attributed to double-chemical nature of abietic acid.

Very Low Level Radioactive Solid Waste Management in CHINA (중국에서의 극저준위 방사성 고체 폐기물 관리)

  • Li, Tingjun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.9 no.2
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    • pp.87-92
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    • 2011
  • This paper introduces the policy and regulations on very low level waste (VLLW) management in China. Given the important decommissioning and site restoration program of the old facility, it is considered necessary to create a new disposal facility dedicated to VLLW. Many general design principles are in common with to the disposal facility for low and intermediate level waste (LILW), namely the isolation of the waste by means of a multibarrier system, but using bentonite and/or high density polyethylene membranes instead of the generalized use of concrete barriers. The design of the facility is consistent with the design of disposal facilities for hazardous waste. The engineering design of two VLLW disposal facilities is introduced.

Long-Term Experiments for Demonstrating Durability of a Concrete Barrier and Gas Generation in a Low-and Intermediate-Level Waste Disposal Facility

  • Kang, Myunggoo;Seo, Myunghwan;Kim, Soo-Gin;Kwon, Ki-Jung;Jung, Haeryong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.19 no.2
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    • pp.267-270
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    • 2021
  • Long-term experiments have been conducted on two important safety issues: long-term durability of a concrete barrier with the steel reinforcements and gas generation from low-and intermediate-level wastes in an underground research tunnel of a radioactive waste disposal facility. The gas generation and microbial communities were monitored from waste packages (200 L and 320 L) containing simulated dry active wastes. In the concrete experiment, corrosion sensors were installed on the steel reinforcements which were embedded 10 cm below the surface of concrete in a concrete mock-up, and groundwater was fed into the mock-up at a pressure of 2.1 bars to accelerate groundwater infiltration. No clear evidence was observed with respect to corrosion initiation of the steel reinforcement for 4 years of operation. This is attributed to the high integrity and low hydraulic conductivity of the concrete. In the gas generation experiment, significant levels of gas generation were not measured for 4 years. These experiments are expected to be conducted for a period of more than 10 years.