Universal Journal of Chemistry(CEASE PUBLICATION) Vol. 4(1), pp. 1 - 9
DOI: 10.13189/ujc.2016.040101
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Study of Chemical Additives in the Cementation of Radioactive Waste of PWR Reactors

Vanessa Mota Vieira ^*, Clédola Cássia Oliveira de Tello
Nuclear Technology Development Center, National Nuclear Energy Commission, Brazil

ABSTRACT

Cementation is a very useful process to solidify radioactive wastes. Depending on the waste it can be necessary to use of chemical additives (admixtures) to improve the cementation process and its product. Admixtures are materials, other than cement, aggregate and water, that are added either before or during the mixing to alter some properties, such as workability, curing temperature range, and setting time. However there are a large variety of these materials that are frequently changed or taken out of the market. In this changeable scenario, it is essential to know the commercially available materials and their characteristics for use in the cementing of radioactive waste. In this research the effects of chemical admixtures in the solidification process has been studied. For the tests, it was prepared a solution simulating the evaporator concentrate waste, cemented by two different formulations, and three chemical admixtures from two manufacturers. The tested admixtures were accelerators, set retarders and superplasticizers. The experiments were organized by a planning factorial 2³ to quantify the effects of formulations, of the admixtures, its quantity and manufacturer in properties of the paste and products. The measured parameters included the density, the viscosity and the setting time of the paste, and the product compressive strength. As future work the leaching test will be performed. The parameter evaluated in this study was the compressive strength for a curing time of 28 days, is considered essential security issues relating to the handling, transport and storage of cemented waste product. The results showed that the addition of accelerators improved the compressive strength of the cemented products.

KEYWORDS
Radioactive Waste, Cementation, Chemical Admixtures, Compressive Strength and Density

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Vanessa Mota Vieira , Clédola Cássia Oliveira de Tello , "Study of Chemical Additives in the Cementation of Radioactive Waste of PWR Reactors," Universal Journal of Chemistry(CEASE PUBLICATION), Vol. 4, No. 1, pp. 1 - 9, 2016. DOI: 10.13189/ujc.2016.040101.

(b). APA Format:
Vanessa Mota Vieira , Clédola Cássia Oliveira de Tello (2016). Study of Chemical Additives in the Cementation of Radioactive Waste of PWR Reactors. Universal Journal of Chemistry(CEASE PUBLICATION), 4(1), 1 - 9. DOI: 10.13189/ujc.2016.040101.