Adsorption Behavior of Cs for Calcium-Aluminosilicate-Hydrate

大輔, 湊; 禎之, 渡邊; 修一, 原澤; 一夫, 山田

doi:10.14250/cement.69.53

Cited by 3 publications

(1 citation statement)

References 14 publications

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“…Some of these studies modeled the adsorption behavior of Na and K on C-A-S-H and reported that the amount of adsorption of monovalent cations increases with the entry of Al into C-S-H . In addition, Minato et al (2015) evaluated the adsorption behavior of Cs and reported that the amount of Cs adsorbed on C-A-S-H is higher than that adsorbed on C-S-H. In view of the latest findings, it is thus reasonable to model the adsorption behavior of Cs and Sr on C-A-S-H rather than on C-S-H.…”

Section: Thermodynamic Equilibrium Model Of C-s-hmentioning

confidence: 99%

Cement and Concrete for Nuclear Waste Management

Nakarai¹,

Kosakowski²

2022

ACT

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The safe management and disposal of radioactive wastes are of critical importance for maintaining a sustainable society. In nuclear waste management, cement and concrete are commonly used to immobilize radioactive waste. Cementation is a common technique used for conditioning low-level and intermediate-level radioactive wastes, which should ensure safe interim storage of waste packages, and act as a first long-term barrier during waste disposal. In addition, cement-based materials are utilized for construction and barrier materials in surface disposals for very low-level to low-level waste and deep geological disposals for low-level, intermediate-level, and high-level wastes.Furthermore, recovery from the nuclear disaster at the Fukushima Daiichi Nuclear Power Station (F1NPS) is an important and urgent issue in Japan. To solve the difficult problems associated with radioactive contaminated materials in the plant and in the environment, contributions of cement and concrete technologies are highly expected.The understanding end prediction of the long-term evolution of cement materials interacting with wastes and other barrier materials during interim and final storage is indispensable and needs to be studied by experts from different scientific and engineering disciplines. The very long times associated with the safe disposal of radioactive waste, which are well beyond the lifetime of ordinal engineered structures and therefore not experimentally accessible, make this task even more demanding.In the first part of this special issue, three technical contributions summarize research and development projects for nuclear waste management with cement and concrete technologies in Japan. and Ichikawa and Hamamoto (19-1275) give general overviews on the use of cement-based materials for low-level radioactive waste (LLW) and for high-level radioactive waste (HLW), respectively. Furthermore, Abe and Iida (20-236) present a comparative discussion of approaches used for LLW in Japan and Belgium.In the second part, the contributions concentrate on processes and applications related to the performance assessment of cement and concrete for nuclear waste management. The scientific papers describe sorption experiments with Cl, I, HTO, and C by Nedyalkova et al. (19-811), diffusion experiments with NaCl of leached cement paste by Kurmisawa et al. (19-426), leaching experiments of cement paste with quick setting admixture by Yokozeki et al. (19-1173), immersion experiments of cement-bentonite samples by Nakarai et al. (19-433, 19-447), and chemo-mechanical modelling of degraded concrete by Oda et al. (19-1075).Finally, the third part contains contributions that investigate, in a broad sense, how cement and concrete technologies can be used to deal with the aftermath of the F1NPS nuclear disaster. At first, a technical paper by summarizes the outcome of a research initiative that aimed at identifying the cause and extent of radioactive contamination of concrete at the F1NPS.A set of scientific contributions is related to water abso...

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Section: Thermodynamic Equilibrium Model Of C-s-hmentioning

confidence: 99%

Cement and Concrete for Nuclear Waste Management

Nakarai¹,

Kosakowski²

2022

ACT

View full text Add to dashboard Cite

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Sorption behavior of cesium ions to Mg-containing calcium silicate hydrate in a co-precipitation process

Seki,

Oasa,

Chida

et al. 2024

MRS Advances

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The sorption behavior of Cs to Mg-containing calcium silicate hydrate (C–S–H) was examined to consider C–S–H formation under the water-saturated conditions around a radioactive waste repository. The amount of Cs sorption was slightly lower for Mg-containing C–S–H than for C–S–H, because Mg leads to a decrease in sorption sites by facilitating the polymerization of silicate chains. However, the apparent sorption distribution coefficient Kd of Cs on C–S–H with a Ca/Si molar ratio of 0.8 and Mg contents up to 20% was estimated to be 3.4–6.1 mL/g. Furthermore, the amount of Cs sorption was not decreased by the presence of Ba. The apparent Kd obtained in this study was about 10 times higher than that conventionally estimated for host rocks in the plutonic repository, indicating that C–S–H retains the effect of Cs immobilization even when it contains Mg. Graphical abstract

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