• Title/Summary/Keyword: Nuclear waste

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Data-Driven Modelling of Damage Prediction of Granite Using Acoustic Emission Parameters in Nuclear Waste Repository

  • Lee, Hang-Lo;Kim, Jin-Seop;Hong, Chang-Ho;Jeong, Ho-Young;Cho, Dong-Keun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.19 no.1
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    • pp.75-85
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    • 2021

  • Evaluating the quantitative damage to rocks through acoustic emission (AE) has become a research focus. Most studies mainly used one or two AE parameters to evaluate the degree of damage, but several AE parameters have been rarely used. In this study, several data-driven models were employed to reflect the combined features of AE parameters. Through uniaxial compression tests, we obtained mechanical and AE-signal data for five granite specimens. The maximum amplitude, hits, counts, rise time, absolute energy, and initiation frequency expressed as the cumulative value were selected as input parameters. The result showed that gradient boosting (GB) was the best model among the support vector regression methods. When GB was applied to the testing data, the root-mean-square error and R between the predicted and actual values were 0.96 and 0.077, respectively. A parameter analysis was performed to capture the parameter significance. The result showed that cumulative absolute energy was the main parameter for damage prediction. Thus, AE has practical applicability in predicting rock damage without conducting mechanical tests. Based on the results, this study will be useful for monitoring the near-field rock mass of nuclear waste repository.

  • https://doi.org/10.7733/jnfcwt.2021.19.1.75 인용 PDF KSCI

Implementation of waste silicate glass into composition of ordinary cement for radiation shielding applications

  • Eid, Mohanad S.;Bondouk, I.I.;Saleh, Hosam M.;Omar, Khaled M.;Sayyed, M.I.;El-Khatib, Ahmed M.;Elsafi, Mohamed
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1456-1463
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    • 2022

  • The aim of this work is to study the radiation shielding properties of cement samples with waste glass incortated into its composition. The mass attenuation coefficient (MAC) of the samples were experimentally determined to evaluate their radiation shielding ability. The experimental coefficient was evaluated using NaI detector for gamma energies between 59.53 keV and 1408.01 keV using different radioactive point sources Am-241, Eu-152, Co-60, and Cs-137, and the gamma transmission parameters half-value layer, mean free path, and transmission factor were calculated. The theoretical coefficient of the composites was determined using Geant4 and XCOM software. The results were also compared against Geant4 and XCOM simulations by calculating the relative deviation between the values to determine the accuracy of the results. In addition the mechanical properties (including Compressive and porosity) as well as the thermogravimetric analysis were tested for the present samples. Overall, it was concluded that the cement sample with 50% waste glass has the greatest shielding potential for radiation shielding applications and is a useful way to reuse waste glass.

  • https://doi.org/10.1016/j.net.2021.10.007 인용 PDF KSCI

Recent Advances in the Removal of Radioactive Wastes Containing 58Co and 90Sr from Aqueous Solutions Using Adsorption Technology

  • Alagumalai, Krishnapandi;Ha, Jeong Hyub;Choi, Suk Soon
    • Applied Chemistry for Engineering
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    • v.33 no.4
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    • pp.352-366
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    • 2022

  • Nuclear power plant operations for electricity generation, rare-earth mining, nuclear medical research, and nuclear weapons reprocessing considerably increase radioactive waste, necessitating massive efforts to eradicate radioactive waste from aquatic environments. Cobalt (58Co) and strontium (90Sr) radioactive elements have been extensively employed in energy generation, nuclear weapon testing, and the manufacture of healthcare products. The erroneous discharge of these elements as pollutants into the aquatic system, radiation emissions, and long-term disposal is extremely detrimental to humans and aquatic biota. Numerous methods for treating radioactive waste-contaminated water have emerged, among which the adsorption process has been promoted for its efficacy in eliminating radioactive waste from aquatic habitats. The current review discusses the adsorptive removal of radioactive waste from aqueous solutions using low-cost adsorbents, such as graphene oxide, metal-organic frameworks, and inorganic metal oxides, as well as their composites. The chemical modification of adsorbents to increase their removal efficiency is also discussed. Finally, the current state of 58Co and 90Sr removal performances is summarized and the efficiencies of various adsorbents are compared.

  • https://doi.org/10.14478/ace.2022.1073 인용 PDF KSCI