• 제목/요약/키워드: Radioactive Waste Vitrification

검색결과 51건 처리시간 0.02초

Fabrication and Characterization of Zr and Hf Containing Vitrified Forms of Radioactive Waste

  • Young Hwan Hwang;Seong-Sik Shin;Sunghoon Hong;Jung-Kwon Son;Cheon-Woo Kim
    • 방사성폐기물학회지
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    • 제22권2호
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    • pp.173-183
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    • 2024

  • Vitrification, one of the most promising solidification processes for various materials, has been applied to radioactive waste to improve its disposal stability and reduce its volume. Because the thermal decomposition of dry active waste (DAW) significantly reduces its volume, the volume reduction factor of DAW vitrification is high. The KHNP developed the optimal glass composition for the vitrification of DAW. Since vitrification offers a high-volume reduction ratio, it is expected that disposal costs could be greatly reduced by the use of such technology. The DG-2 glass composition was developed to vitrify DAW. During the maintenance of nuclear power plants, metals containing paper, clothes, and wood are generated. ZrO2 and HfO2 are generally considered to be network-formers in borosilicate-based glasses. In this study, a feasibility study of vitrification for DAW that contains metal particulates is conducted to understand the applicability of this process under various conditions. The physicochemical properties are characterized to assess the applicability of candidate glass compositions.

  • https://doi.org/10.7733/jnfcwt.2024.022 인용 PDF

Determination of reaction kinetics during vitrification of radioactive liquid waste for different types of base glass

  • Suneel, G.;Rajasekaran, S.;Selvakumar, J.;Kaushik, Chetan P.;Gayen, J.K.;Ravi, K.V.
    • Nuclear Engineering and Technology
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    • 제51권3호
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    • pp.746-754
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    • 2019

  • Vitrification of radioactive liquid waste (RLW) provides a feasible solution for isolating radionuclides from the biosphere for an extended period. In vitrification, base glass and radioactive waste are added simultaneously into the melter. Determination of heat and mass transfer rates is necessary for rational design and sizing of melter. For obtaining an assured product quality, knowledge of reaction kinetics associated with the thermal decomposition of waste constituents is essential. In this study Thermogravimetry (TG) - Differential Thermogravimetry (DTG) of eight kinds of nitrates and two oxides, which are major components of RLW, is investigated in the temperature range of 298-1273 K in the presence of base glasses of five component (5C) and seven component (7C). Studies on thermal behavior of constituents in RLW were carried out at heating rates ranging from 10 to $40\;K\;min^{-1}$ using TG - DTG. Thermal behavior and related kinetic parameters of waste constituents, in the presence of 5C and 7C base glass compositions were also investigated. The activation energy, pre-exponential factor and order of the reaction for the thermal decomposition of 24% waste oxide loaded glasses were estimated using Kissinger method.

  • https://doi.org/10.1016/j.net.2018.12.002 인용 PDF KSCI

Glass Property Models, Constraints, and Formulation Approaches for Vitrification of High-Level Nuclear Wastes at the US Hanford Site

  • Kim, Dongsang
    • 한국세라믹학회지
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    • 제52권2호
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    • pp.92-102
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    • 2015

  • Current plans for legacy nuclear wastes stored in underground tanks at the U.S. Department of Energy's Hanford Site in Washington are that they will be separated into high-level waste and low-activity waste fractions that will be vitrified separately. Formulating optimized glass compositions that maximize the waste loading in glass is critical for successful and economical treatment and immobilization of these nuclear wastes. Glass property-composition models have been developed and applied to formulate glass compositions for various objectives for the past several decades. Property models with associated uncertainties combined with composition and property constraints have been used to develop preliminary glass formulation algorithms designed for vitrification process control and waste-form qualification at the planned waste vitrification plant. This paper provides an overview of the current status of glass property-composition models, constraints applicable to Hanford waste vitrification, and glass formulation approaches that have been developed for vitrification of hazardous and highly radioactive wastes stored at the Hanford Site.

  • https://doi.org/10.4191/kcers.2015.52.2.92 인용 PDF KSCI

중$\cdot$저준위 방사성폐기물 유리화 시설의 차폐해석에 관한 연구 (A Study on the Shielding Analysis in Vitrification Facility of Low-and Intermediate Level Radioactive Wastes)

  • 이창민;이건재;지평국;박종길;하종현;송명재
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.524-531
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    • 2003

  • 중$\cdot$저준위 방사성폐기물의 유리화 기술은 체적감소비, 유리고화체의 기계적 및 화학적 안전성 등으로 그 유용성이 입증되어 현재 울진 5,6호기에 상용시설의 건설이 추진되고 있다. 유리화시설은 대상폐기물의 높은 방사능 준위로 인해 방사선 안전 설계를 위해서는 차폐해석이 수반되어야 한다. 그러나 국내에서는 유리화 시설의 건설 및 운영 경험이 없으므로, 본 연구에서는 유리화 시설의 향후 상세 설계와 운영계획에 도움을 줄 수 있는 자료를 얻고자 유리화 실증시설의 구조를 따라 기존의 방사선원항을 이용하여 기기별 선량계산을 통해 방사선 차폐 해석을 수행하였다. 차폐체로서는 경제성과 열저항성이 뛰어난 콘크리트를 고려하였다.

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