Search | Korea Science

Young Hwan Hwang;Seong-Sik Shin;Sunghoon Hong;Jung-Kwon Son;Cheon-Woo Kim
- Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
- /
- v.22 no.2
- /
- pp.173-183
- /
- 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

Suneel, G.;Rajasekaran, S.;Selvakumar, J.;Kaushik, Chetan P.;Gayen, J.K.;Ravi, K.V.
- Nuclear Engineering and Technology
- /
- v.51 no.3
- /
- pp.746-754
- /
- 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

Kim, Dongsang
- Journal of the Korean Ceramic Society
- /
- v.52 no.2
- /
- pp.92-102
- /
- 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

이창민;이건재;지평국;박종길;하종현;송명재
- Proceedings of the Korean Radioactive Waste Society Conference
- /
- 2003.11a
- /
- pp.524-531
- /
- 2003
The usefulness of vitrification technology for low- and intermediate- level radioactive wastes was demonstrated because of high volume reduction, mechanical and chemical stability of final waste forms. Thus, a construction of the commercial vitrification plant Is currently promoted. Due to the high radiation level of the waste, shielding analysis has to be carried out for safe design in a vitrification facility. Because there has been no experience in the construction and operation of the vitrification facility in Korea, in this study, in order to get some information for help the detailed design and plan for operation in vitrification facility, shielding analysis for each facility in pilot plant is carried out by using source term from established study. For the selection of the shielding material, concrete was chosen compared to the lead because of economic advantage, weight consideration, and thermal resistance.
PDF