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  • Author or Editor: G. Guliš x
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Abstract  

The intermediate level liquid radioactive wastes (RAW) isussed from nuclear power plants have high salt contents ca 200 g·dm–3, the pH of liquid RAW being 12.5–13.7. A convenient method for separation of cesium under these conditions is solvent extraction with substituted phenols. For this purpose weere tested antioxidants produced in Czechoslovakia: AO 2246 [2,2-methylene-bis-(4-methyl-6-tertbutyl)phenol]; AO 4 [2-tertbutyl-4-(2-phenylpropyl)phenol]; AO 4K [2,6-ditertbuty-4-methylphenol]; AO 301 [2,2-methylene-bis-(4-{2-phenylpropyl}-6-tert-butyl)phenol]; and one antioxidant imporoted from Japan—NOCRAC 2246. This antioxidant is equivalent to AO 2246. After the first experiment it was found that the extraction efficiency for antioxidants AO 4 and Ao 301 is very low and the following experiments were made with AO 2246 (NOCRAC 2246) and AO 4K. Some effects on extracton as, pH of water phase, influence of diluent, influence of concentration of antioxidants, extraction time, were studied. The best results gave antioxidant NOCRAC 2246 in nitrobenzene, the extraction efficiency was 92.3% with pH 13.23.

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Abstract  

The incineration is one of the widely used method for treatment of solid radioactive wastes. The high volume and weight reduction coefficient (100–150 respectively 10–15) are advantages of this method. The greater part of radionuclides from solid radioactive wastes is retained in ash. From point of view of workers external irradiation, the radionuclides accumulation in furnace lining is one of risk factors. The Kalinit O 1200 is furnace lining material on NPPRIs Experimental Incineration facility. In the first step the sorption properties of this material from137Cs,60Co,54Mn,65Zn solutions were studied. The best results had60Co, its distribution coefficient was 7036 kg · dm–3. Cesium-137 was not absorbed on this material. The cylinders (height 5 cm, diameter 2 cm) from lining materials were made latest and were applicated inside the furnace and technological tract to study sorption properties from combustion gases. The penetration of radionuclide into lining material was studied too. The results obtained with this experiments are described in this paper.

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Abstract  

The antioxidant Lowinox 22M46 (Naftonox 22M46) were used for the extraction of cesium from intermediate level liquid radioactive wastes.

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Abstract  

Information about the sorption of radionuclides on natural materials used for cementation of liquid radioactive wastes (RAW) is important for predictions of migration rates of radionuclides in the products of fixation. Cementation process for conditioning liquid RAW uses, besides cement, materials which improve quality of products. In Czechoslovakia technology among these materials are clinoptilolite tuffit, mordenite tuff, tobermorite and fly ash. Liquid RAW issued from nuclear power plants contains the principal radionuclides60Co,134Cs and137Cs, therefore, a sorption study of these radionuclides was carried out. pH of liquid RAW was 12.5–13.7 and salt content ca. 200 g·dm–3. Results of sorption are given by distribution coefficients. The best results for cesium in those pH region and salt content had mordenite tuff DCs=100 dm3·kg–1 and the worst results had fly ash DCs=4.1 dm3·kg–1. The best results for cobalt in those solutions had tobermorite DCo=38 dm3·kg–1 and the worst results had fly ash DCo=6.9 dm3·kg–1.

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