2010 2nd International Conference on Reliability, Safety and Hazard - Risk-Based Technologies and Physics-of-Failure Methods (ICRESH), 2010
Abstract An Ion Exchange (IEX) process is being adopted for treatment of intermediate level radio... more Abstract An Ion Exchange (IEX) process is being adopted for treatment of intermediate level radioactive liquid waste (ILW) streams generated during reprocessing of spent nuclear fuel. In this process separation of Cesium and Strontium from waste is achieved using highly ...
Radioactive waste streams are generated at various stages of uranium and thorium fuel cycles. Tre... more Radioactive waste streams are generated at various stages of uranium and thorium fuel cycles. Treatment and storage/disposal of low and intermediate level wastes (LILW) from U fuel cycle are being practiced in various countries, which have adopted either open or closed fuel cycles for nuclear power generation. The spent nuclear fuel (SNF) from open fuel cycle is being stored. In the case of processing of SNF for closed fuel cycle, the resultant high-level liquid waste (HLW) is solidified by immobilization in an inert matrix like glass, and stored in engineered facilities. The research and development work is being pursued in various countries on disposal of SNF and solidified HLW in deep geological formations. In the case of thorium fuel cycle, since the mining is generally in shallow sea coastal areas, the waste generation is comparatively less. Process and technology for treatment and disposal of the wastes generated during mining and milling of monazite for recovery of thorium and associated rare earth (RE) elements is well established. Waste management practices with respect to the waste generated in fabrication of Th-based fuel and in operation of Th-fuelled reactors will not be much different from similar uranium fuel-based facilities. However, in the immobilization of HLW from the reprocessing of Th-based SNF, some challenges are likely on account of difficulty in dissolution of thorium oxide in concentrated nitric acid which necessitates the use of fluorides and aluminum. The results of R&D on the aspects of reduction of concentration of fluorides and aluminum in the waste, incorporation of thorium oxide in boro-silicate glass matrix, and its impact on the characteristics of vitrified waste product (VWP) as well as future areas of research are discussed in this chapter.
Use of NiS coprecipitation was found to be very effective at a concentration level of 2500 ppm of... more Use of NiS coprecipitation was found to be very effective at a concentration level of 2500 ppm of Ni and 1300 ppm of S for the effective removal of Ru from the effluent stream. However, the NiS precipitate increases the sludge volume. Efforts were made to form the composite material of NiS in combination with Poly methyl metha acrylate (PMMA) polymer beads. The NiS–PMMA composite beads were loaded in a column and its ruthenium uptake behavior was studied. The NiS–PMMA beads were found to be functioning satisfactorily in alkaline conditions. It has shown a Kd value of about 8000–9000. The NiS–PMMA composite material has also shown the potential for the uptake of Sb. The effect of salt concentration on the Kd value is negligible. The equilibrium conditions are achieved in around 25–30 min in batch mode of operation. The composite material can be suitably used in the column mode of operation.
The present manuscript describes preparation, characterization and study of electrical behavior o... more The present manuscript describes preparation, characterization and study of electrical behavior of barium borosilicate glasses with varying concentrations of ThO2, maintaining constant molar ratios of SiO2:B2O3:Na2O:BaO for all samples. The effect of ThO2 incorporation on the ionic conductivity of glasses was studied by ac impedance analyzer, below the glass transition temperature. The diffusion coefficient (D) of the mobile Na+ is
Potential of Chromolaena odorata plants for remediation of (137)Cs from solutions and low level n... more Potential of Chromolaena odorata plants for remediation of (137)Cs from solutions and low level nuclear waste was evaluated. When plants were exposed to solutions spiked with three different levels of (137)Cs, namely 1 x 10(3) kBqL(-1), 5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1), 89%, 81% and 51% of (137)Cs was found to be remediated in 15 d, respectively. At the lowest Cs activity (1 x 10(3) kBqL(-1)), accumulation of Cs was found to be higher in roots compared to shoots, while at higher Cs activities (5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1)), Cs accumulation was more in shoots than roots. When plants were incubated in low level nuclear waste, 79% of the activity was removed by plants at the end of 15 d. The present study suggests that C. odorata could be used as a potential candidate plant for phytoremediation of (137)Cs.
The present manuscript describes the preparation, characterization and electrical behavior of sod... more The present manuscript describes the preparation, characterization and electrical behavior of sodium borosilicate glasses with varying concentrations of BaO, while maintaining the SiO(2):B(2)O(3):Na(2)O ratios constant for all the samples. The effect of BaO substitution on the ionic conductivity of glasses was studied by ac impedance analyzer, below the glass transition temperature. The diffusion coefficient (D) of each sample has been determined from the values of electrical conductivity and density. The activation energy for sodium ion transport has been calculated from the values of diffusion coefficients at different temperatures. The electrical properties of the modified glass have been explained on the basis of the structural factor.
Barium borosilicate glass was found to have high uptake capacity for many cations. To improve its... more Barium borosilicate glass was found to have high uptake capacity for many cations. To improve its selectivity, surface modification was carried out. In order to make the glass selective towards uranyl ion, organic ligands like tri-n-octylphosphine oxide (TOPO) and 8-hydroxy quinoline (Oxine) were used. It was observed that the surface modification resulted in the change in uptake property of the glass. The uptake process was faster and within 5 h, 90% of the uranyl ion could be taken up from a 0.01 mM solution. With use of the modified barium borosilicate glass and EDTA as masking agent, uranyl ion could be selectively removed from mixtures of cations.
Barium borosilicate (BBS) and sodium borosilicate (SBS) glass samples, prepared by the convention... more Barium borosilicate (BBS) and sodium borosilicate (SBS) glass samples, prepared by the conventional melt-quench method, were used for the uptake of Rhodamine 6G dye from aqueous solution. The experimental conditions were optimized to get maximum uptake and was found to be 0.4 mg of dye per gram of BBS glass sample. For the same network former to modifier ratio, barium borosilicate glasses are found to have improved extent of uptake for the dye molecules from aqueous solutions compared to sodium borosilicate glasses. Based on 29Si MAS NMR studies on these glasses, it is inferred that significantly higher number of non-bridging oxygen atoms present in barium borosilicate glasses compared to sodium borosilicate glasses is responsible for its improved uptake of Rhodamine 6G dye. 11B MAS NMR studies have confirmed the simultaneous existence of boron in BO3 and BO4 configurations in both barium borosilicate and sodium borosilicate glasses. The luminescence studies have established that the dye molecule is incorporated into the glass matrix through ion exchange mechanism by replacing the exchangeable ions like Na+/Ba2+ attached with the non-bridging oxygen atoms present in the glass.
... [5] Anil Kakodkar, Proceedings of the International Seminar on the Role of Nuclear Energy for... more ... [5] Anil Kakodkar, Proceedings of the International Seminar on the Role of Nuclear Energy for Sustainable Development New Delhi, India (1997), p. 62. [6] B. Bhattacharjee, Proceedings of the Conference on Nuclear Fuel Cycle INSAC-2003 Kalpakkam, India (2003). ...
2010 2nd International Conference on Reliability, Safety and Hazard - Risk-Based Technologies and Physics-of-Failure Methods (ICRESH), 2010
Abstract An Ion Exchange (IEX) process is being adopted for treatment of intermediate level radio... more Abstract An Ion Exchange (IEX) process is being adopted for treatment of intermediate level radioactive liquid waste (ILW) streams generated during reprocessing of spent nuclear fuel. In this process separation of Cesium and Strontium from waste is achieved using highly ...
Radioactive waste streams are generated at various stages of uranium and thorium fuel cycles. Tre... more Radioactive waste streams are generated at various stages of uranium and thorium fuel cycles. Treatment and storage/disposal of low and intermediate level wastes (LILW) from U fuel cycle are being practiced in various countries, which have adopted either open or closed fuel cycles for nuclear power generation. The spent nuclear fuel (SNF) from open fuel cycle is being stored. In the case of processing of SNF for closed fuel cycle, the resultant high-level liquid waste (HLW) is solidified by immobilization in an inert matrix like glass, and stored in engineered facilities. The research and development work is being pursued in various countries on disposal of SNF and solidified HLW in deep geological formations. In the case of thorium fuel cycle, since the mining is generally in shallow sea coastal areas, the waste generation is comparatively less. Process and technology for treatment and disposal of the wastes generated during mining and milling of monazite for recovery of thorium and associated rare earth (RE) elements is well established. Waste management practices with respect to the waste generated in fabrication of Th-based fuel and in operation of Th-fuelled reactors will not be much different from similar uranium fuel-based facilities. However, in the immobilization of HLW from the reprocessing of Th-based SNF, some challenges are likely on account of difficulty in dissolution of thorium oxide in concentrated nitric acid which necessitates the use of fluorides and aluminum. The results of R&D on the aspects of reduction of concentration of fluorides and aluminum in the waste, incorporation of thorium oxide in boro-silicate glass matrix, and its impact on the characteristics of vitrified waste product (VWP) as well as future areas of research are discussed in this chapter.
Use of NiS coprecipitation was found to be very effective at a concentration level of 2500 ppm of... more Use of NiS coprecipitation was found to be very effective at a concentration level of 2500 ppm of Ni and 1300 ppm of S for the effective removal of Ru from the effluent stream. However, the NiS precipitate increases the sludge volume. Efforts were made to form the composite material of NiS in combination with Poly methyl metha acrylate (PMMA) polymer beads. The NiS–PMMA composite beads were loaded in a column and its ruthenium uptake behavior was studied. The NiS–PMMA beads were found to be functioning satisfactorily in alkaline conditions. It has shown a Kd value of about 8000–9000. The NiS–PMMA composite material has also shown the potential for the uptake of Sb. The effect of salt concentration on the Kd value is negligible. The equilibrium conditions are achieved in around 25–30 min in batch mode of operation. The composite material can be suitably used in the column mode of operation.
The present manuscript describes preparation, characterization and study of electrical behavior o... more The present manuscript describes preparation, characterization and study of electrical behavior of barium borosilicate glasses with varying concentrations of ThO2, maintaining constant molar ratios of SiO2:B2O3:Na2O:BaO for all samples. The effect of ThO2 incorporation on the ionic conductivity of glasses was studied by ac impedance analyzer, below the glass transition temperature. The diffusion coefficient (D) of the mobile Na+ is
Potential of Chromolaena odorata plants for remediation of (137)Cs from solutions and low level n... more Potential of Chromolaena odorata plants for remediation of (137)Cs from solutions and low level nuclear waste was evaluated. When plants were exposed to solutions spiked with three different levels of (137)Cs, namely 1 x 10(3) kBqL(-1), 5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1), 89%, 81% and 51% of (137)Cs was found to be remediated in 15 d, respectively. At the lowest Cs activity (1 x 10(3) kBqL(-1)), accumulation of Cs was found to be higher in roots compared to shoots, while at higher Cs activities (5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1)), Cs accumulation was more in shoots than roots. When plants were incubated in low level nuclear waste, 79% of the activity was removed by plants at the end of 15 d. The present study suggests that C. odorata could be used as a potential candidate plant for phytoremediation of (137)Cs.
The present manuscript describes the preparation, characterization and electrical behavior of sod... more The present manuscript describes the preparation, characterization and electrical behavior of sodium borosilicate glasses with varying concentrations of BaO, while maintaining the SiO(2):B(2)O(3):Na(2)O ratios constant for all the samples. The effect of BaO substitution on the ionic conductivity of glasses was studied by ac impedance analyzer, below the glass transition temperature. The diffusion coefficient (D) of each sample has been determined from the values of electrical conductivity and density. The activation energy for sodium ion transport has been calculated from the values of diffusion coefficients at different temperatures. The electrical properties of the modified glass have been explained on the basis of the structural factor.
Barium borosilicate glass was found to have high uptake capacity for many cations. To improve its... more Barium borosilicate glass was found to have high uptake capacity for many cations. To improve its selectivity, surface modification was carried out. In order to make the glass selective towards uranyl ion, organic ligands like tri-n-octylphosphine oxide (TOPO) and 8-hydroxy quinoline (Oxine) were used. It was observed that the surface modification resulted in the change in uptake property of the glass. The uptake process was faster and within 5 h, 90% of the uranyl ion could be taken up from a 0.01 mM solution. With use of the modified barium borosilicate glass and EDTA as masking agent, uranyl ion could be selectively removed from mixtures of cations.
Barium borosilicate (BBS) and sodium borosilicate (SBS) glass samples, prepared by the convention... more Barium borosilicate (BBS) and sodium borosilicate (SBS) glass samples, prepared by the conventional melt-quench method, were used for the uptake of Rhodamine 6G dye from aqueous solution. The experimental conditions were optimized to get maximum uptake and was found to be 0.4 mg of dye per gram of BBS glass sample. For the same network former to modifier ratio, barium borosilicate glasses are found to have improved extent of uptake for the dye molecules from aqueous solutions compared to sodium borosilicate glasses. Based on 29Si MAS NMR studies on these glasses, it is inferred that significantly higher number of non-bridging oxygen atoms present in barium borosilicate glasses compared to sodium borosilicate glasses is responsible for its improved uptake of Rhodamine 6G dye. 11B MAS NMR studies have confirmed the simultaneous existence of boron in BO3 and BO4 configurations in both barium borosilicate and sodium borosilicate glasses. The luminescence studies have established that the dye molecule is incorporated into the glass matrix through ion exchange mechanism by replacing the exchangeable ions like Na+/Ba2+ attached with the non-bridging oxygen atoms present in the glass.
... [5] Anil Kakodkar, Proceedings of the International Seminar on the Role of Nuclear Energy for... more ... [5] Anil Kakodkar, Proceedings of the International Seminar on the Role of Nuclear Energy for Sustainable Development New Delhi, India (1997), p. 62. [6] B. Bhattacharjee, Proceedings of the Conference on Nuclear Fuel Cycle INSAC-2003 Kalpakkam, India (2003). ...
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