Extraction and stripping behaviour of U(VI) from TBP/n-dodecane phase containing the degradation product HDBP
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Mukundan Poornima
Abstract
The separation of uranium and plutonium from the spent nuclear fuel solution is performed by the liquid-liquid extraction of actinides from the fuel solution in to the organic phase consisting of tri-n-butylphosphate (TBP) in n-dodecane (n-DD). In this process, the TBP undergoes chemical and radiolytic degradation to yield dibutylphosphoric acid (HDBP), which is the major degradation product of organic phase. The presence of HDBP in organic phase alters the extraction of actinides to some extent, but severely affects the back extraction of actinides from the loaded organic phase during recovery. In view of this, the present investigation deals with the extraction and stripping behaviour of U(VI) (1 g/L = 0.0042 M) in both the batch and continuous counter-current mode using 1.1 M TBP + 0.015 M HDBP/n-DD. The results were compared with those obtain in the absence of HDBP. The effect of HDBP on the distribution ratio of U(VI) in 1.1 M TBP/n-DD was studied, and the number of contacts required for extraction and stripping of uranium was determined in the cross-current mode. A continuous counter-current extraction experiment was performed in a 16-stage annular centrifugal extractor (ACE) bank and the stage profiling of uranium and nitric acid, and the duration needed for the attainment of steady state was determined. Similarly, the stripping of uranium from the loaded organic phase was performed using 0.01 M nitric acid, as well as with dual acid (4 M and 0.01 M) at different locations of the ACE bank. About three stages were adequate for complete extraction of U(VI) from 4 M nitric acid in to both organic phases. While the recovery of U(VI) from 1.1 M TBP/n-DD was quantitative in six stages, the entire amount of U(VI) was retained in the organic phase containing HDBP during stripping with 0.01 M nitric acid. In contrast to this observation, the stripping of U(VI) from 1.1 M TBP/n-DD with dual acid displayed the unusual accumulation of U(VI) in the ACE bank due to the introduction of 4 M HNO3, which was facilitating the re-extraction of U(VI) in the bank, and the steady state, in this case, was achievable beyond 630 min of the counter-current run. The recovery of U(VI) from the HDBP containing organic phase was negligible during stripping with dual acid, and the poor recovery was essentially attributed to the formation of strong HDBP complexes of uranium retained in the organic phase.
Acknowledgements
The author would like to thank Shri. Chayan Patra for HDBP analysis by Ion Chromatography, Shri. R Rajeev and Dr. N Desigan for technical inputs.
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: Experimental and analytical work: MP, SRR and MBM; Data analysis interpretation and validation: MP, MBM and KAV; Guidance: KAV; Writing - Original draft preparation: MP, SRR, Writing-Review and editing: KAV.
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Use of Large Language Models, AI and Machine Learning Tools: None declared.
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Competing interests: The authors state no conflict of interest.
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Research funding: None declared.
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Data availability: Not applicable.
References
1. Lanham, W. B.; Runion, T. C. Purex Process for Plutonium and Uranium Recovery. ORLN-497; Department of Energy: Washington, DC: DOE Report, 1949.10.2172/4165457Suche in Google Scholar
2. Herbst, R. S.; Baron, P.; Nilsson, M. Standard and Advanced Separation. In PUREX Processes for Nuclear Fuel Reprocessing: Advanced Separation Techniques for Nuclear Fuel Reprocessing and Radioactive Waste Treatment; Woodhead Publishing series in energy: Cambridge, UK, 2011; pp 141–175.10.1533/9780857092274.2.141Suche in Google Scholar
3. Sood, D. D.; Patil, S. K. Chemistry of Nuclear Fuel Reprocessing: Current Status. J. Radioanal. Nucl. Chem. 1996, 203 (2), 547–573; https://doi.org/10.1007/bf02041529.Suche in Google Scholar
4. Dey, P. K.; Bansal, N. K. Spent Fuel Reprocessing: A Vital Link in Indian Nuclear Power Program. Nucl. Eng. Des. 2006, 236, 723–729; https://doi.org/10.1016/j.nucengdes.2005.09.029.Suche in Google Scholar
5. Natarajan, R.; Raj, B. Fast Reactor Fuel Reprocessing Technology: Successes and Challenges. Energy Proc. 2011, 7, 414–420; https://doi.org/10.1016/j.egypro.2011.06.054.Suche in Google Scholar
6. Natarajan, R. Reprocessing of Spent Fast Reactor Nuclear Fuels; Woodhead Publishing series in energy: Cambridge, UK, 2015; pp 213–243.10.1016/B978-1-78242-212-9.00009-5Suche in Google Scholar
7. Natarajan, R. Reprocessing of Spent Nuclear Fuel in India: Present Challenges and Future Programme. Prog. Nucl. Energy 2017, 101, 118–132; https://doi.org/10.1016/j.pnucene.2017.03.001.Suche in Google Scholar
8. Mincher, B. J.; Modolo, G.; Mezyk, S. P. Review Article: the Effects of Radiation Chemistry on Solvent Extraction: 1. Conditions in Acidic Solution and a Review of TBP Radiolysis. Solvent Extr. Ion Exch. 2009, 27 (1), 1–25. https://doi.org/10.1080/07366290802544767.Suche in Google Scholar
9. Wright, A.; Paviet-Hartmann, P. Review of Physical and Chemical Properties of Tributyl phosphate/Diluent/Nitric Acid Systems. Sep. Sci. Technol. 2010, 45 (12), 1753–1762; https://doi.org/10.1080/01496395.2010.494087.Suche in Google Scholar
10. Wang, Y.; Wan, Y.; Cai, Y.; Yuan, L.; Feng, W.; Liu, N. A Review of the Alpha Radiolysis of Extractants for Actinide Lanthanide Separation in Spent Nuclear Fuel Reprocessing. Radiochim. Acta 2021, 109 (8), 603–623. https://doi.org/10.1515/ract-2021-1009.Suche in Google Scholar
11. Tripathi, S. C.; Ramanujam, A. Effect of Radiation-Induced Physicochemical Transformations on Density and Viscosity of 30 % TBP - n-Dodecane - HNO3 System. Sep. Sci. Technol. 2003, 38 (10), 2307–2326; https://doi.org/10.1081/ss-120021626.Suche in Google Scholar
12. IAEA Status and Trends in Spent Fuel and Radioactive Waste Management. IAEA Nucl. Energy Ser. 2002, 14 (Rev. 1), 14. No. NW-T-1.Suche in Google Scholar
13. Govindan, P.; Sukumar, S.; Vijayan, K. S.; Kumar, G. S.; Ganesh, S.; Sharma, P. K.; Dhamodharan, K.; Rao, R. V. S.; Venkataraman, M.; Natarajan, R. Recovery of Plutonium from Carbonate Wash Solutions. J. Radioanal. Nucl. Chem. 2010, 284, 151–156; https://doi.org/10.1007/s10967-010-0456-1.Suche in Google Scholar
14. Fedorov, Y. S.; Zilberman, B. Y.; Kulikov, S. M.; Blazheva, I. V.; Mishin, E. N.; Wallwork, A. L.; Deniss, I. S.; May, I.; Hill, N. J. Uranium(Vi) Extraction by TBP in the Presence of HDBP. Solvent Extr. Ion Exch. 1999, 17 (2), 243–257; https://doi.org/10.1080/07366299908934611.Suche in Google Scholar
15. May, B. I.; Taylor, R. J.; Wallwork, A. L.; Hastings, J. J.; Fedorov, Y. S.; Ya Zilberman, B.; Mishin, E. N.; Arkhipov, S. A.; Blazheva, I. V.; Ya Poverkova, L.; Livens, F. R.; Charnock, J. M. The Influence of Dibutylphosphate on Actinide Extraction by 30 % Tributylphosphate. Radiochim. Acta 2000, 88, 283–290; https://doi.org/10.1524/ract.2000.88.5.283.Suche in Google Scholar
16. Mishra, S.; Rama Swami, K.; Rajesh, P.; Desigan, N.; Venkatesan, K. A. Effect of Di-Butyl Phosphate on the Distribution Behaviour of Uranyl Ions in PUREX Solvent. Sep. Sci. Technol. 2024, 59 (1), 112–121; https://doi.org/10.1080/01496395.2024.2315615.Suche in Google Scholar
17. Manavalan, B.; Joshi, J. B.; Pandey, N. K. Design Modification in the Stationary Bowl of Annular Centrifugal Extractors to Handle Adverse Conditions. Ind. Eng. Chem. Res. 2020, 59 (25), 11757–11756; https://doi.org/10.1021/acs.iecr.0c00181.Suche in Google Scholar
18. Baker, A.; Fells, A.; Shaw, T.; Maher, C. J.; Hanson, B. C. Effect of Scale-Up on Residence Time and Uranium Extraction on Annular Centrifugal Contactors (ACCs). Sep. 2023, 10 (6), 1–18; https://doi.org/10.3390/separations10060331.Suche in Google Scholar
19. Chitnis, R. T.; Kulkarni, R. T.; Rege, S. G.; Mukherjee, A. Volumetric Method for the Determination of Uranium in the Active Process Solution. J. Radioanal. Nucl. Chem. 1978, 45, 331–339; https://doi.org/10.1007/bf02519600.Suche in Google Scholar
20. Florence, T. M.; Yvonne, F. Spectrophotometric Determination of Uranium with 4-(2-Pyridylazo) Resorcinol. Anal. Chem. 1963, 35 (11), 1613–1616; https://doi.org/10.1021/ac60204a020.Suche in Google Scholar
21. Velavendan, P.; Ganesh, S.; Pandey, N. K.; Kamachi Mudali, U.; Natarajan, R. Comparative Studies on the Determination of Di-n-Butyl Phosphate in Degraded Solvent of PUREX Process by Ion Chromatography and Gas Chromatography Methods. Desalin. Water Treat. 2012, 49, 123–129; https://doi.org/10.1080/19443994.2012.708208.Suche in Google Scholar
22. Giridhar, P.; Venkatesan, K. A.; Srinivasan, T. G.; Vasudeva Rao, P. R. Extraction of Uranium(VI) from Nitric Acid Medium by 1.1M Tri-n-Butylphosphate in Ionic Liquid Diluent. J. Radioanal. Nucl. Chem. 2005, 265 (1), 31–38; https://doi.org/10.1007/s10967-005-0785-7.Suche in Google Scholar
23. McDonald, L. W.; Campbell, J. A.; Vercouter, T.; Clark, S. B. Characterization of Actinides Complexed to Nuclear Fuel Constituents Using ESI-MS. Anal. Chem. 2016, 88 (5), 2614–2621; https://doi.org/10.1021/acs.analchem.5b03352.Suche in Google Scholar PubMed
24. Hahn, H. T.; Vander Wall, E. M. Complex Formation in the Dilute Uranyl Nitrate-Nitric Acid-Dibutyl Phosphoric Acid-Tributyl Phosphate-Amsco System. J. Inorg. Nucl. Chem. 1964, 26 (1), 191–202; https://doi.org/10.1016/0022-1902-64-80245-1.Suche in Google Scholar
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