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Agarwal R, Gamare JS, Nandi C, Phatak R, Sharma MK, Jayachandran K, Kaity S. A "Two-Step" Electrochemical Approach for Recovery of Plutonium and Uranium from Aqueous Acidic Waste Solutions. Inorg Chem 2024; 63:2090-2097. [PMID: 38235667 DOI: 10.1021/acs.inorgchem.3c03926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Chemical quality control of nuclear fuel, particularly the determination of Pu and U contents by chemical methods, results in analytical acidic aqueous waste solutions from which Pu and U must be recovered efficiently for the remediation of radioactive wastes. Reported methods involve several complicated steps requiring addition of chemical oxidants/reductants for valence adjustments and generation of secondary wastes, thereby making the recovery process cumbersome. Herein, we report a novel two-step electrochemical approach for Pu and U recovery from acidic aqueous waste solutions containing different metallic impurities (Fe, Cr, Mn, Cd, Al, Ni, Co, Zn, and Mg) by bulk electrolysis using a Pt gauze electrode. Pu and U are recovered from these waste solutions in a two-step process: (i) bulk electrolysis of the mixed solution at a constant potential of 0.1 V vs Ag/AgCl/3 M KCl that results in the reduction of PuO22+ to Pu3+ followed by the precipitation of Pu3+ as K2(K0.5Pu0.5)(SO4)2, which is then filtered and separated and (ii) the filtrate solution is again subjected to bulk electrolysis at a constant potential of -0.35 V vs Ag/AgCl/3 M KCl resulting in the reduction of UO22+ to U4+. The U4+ is then precipitated as K2(K0.67U0.33)(SO4)2, which is filtered and separated, leading to a Pu- and U-free aqueous acidic waste solutions. Biamperometry shows that 97.8% and 99.1% recovery of Pu and U, respectively, is possible, and emission spectrometry confirms the purity of K2(K0.5Pu0.5)(SO4)2 and K2(K0.67U0.33)(SO4)2. Because of its operational simplicity, potential for remote handling, and excellent extraction efficiency, the present methodology can easily replace traditional methods for the recovery of Pu and U from acidic aqueous waste solutions.
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Affiliation(s)
- Rahul Agarwal
- Homi Bhabha National Institute, Mumbai 400 094, India
- Fuel Chemistry Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
| | - Jayashree S Gamare
- Fuel Chemistry Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
| | - Chiranjit Nandi
- Radiometallurgy Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400085, India
| | - Rohan Phatak
- Fuel Chemistry Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
| | - Manoj K Sharma
- Homi Bhabha National Institute, Mumbai 400 094, India
- Fuel Chemistry Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
| | - Kavitha Jayachandran
- Fuel Chemistry Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
| | - Santu Kaity
- Radiometallurgy Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400085, India
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Kumar SS, Srivastava A, Rao A. Biodegradable Methane Sulfonic Acid-Based Nonaqueous Dissolution, Estimation, and Recovery: Toward Development of a Simplified Scheme for Plutonium-Bearing Fuel Matrices. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c03473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Shiny S. Kumar
- Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai400 085, India
- Homi Bhabha National Institute, Mumbai400094, India
| | - Ashutosh Srivastava
- Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai400 085, India
- Homi Bhabha National Institute, Mumbai400094, India
| | - Ankita Rao
- Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai400 085, India
- Homi Bhabha National Institute, Mumbai400094, India
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Plutonium assay by spectrophotometry and estimation of uncertainties on routine glove box samples. J Radioanal Nucl Chem 2020. [DOI: 10.1007/s10967-020-07369-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Plutonium (IV) Quantification in Technologically Relevant Media Using Potentiometric Sensor Array. SENSORS 2020; 20:s20061604. [PMID: 32183104 PMCID: PMC7147468 DOI: 10.3390/s20061604] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/03/2020] [Accepted: 03/10/2020] [Indexed: 01/03/2023]
Abstract
The quantification of plutonium in technological streams during spent nuclear fuel (SNF) reprocessing is an important practical task that has to be solved to ensure the safety of the process. Currently applied methods are tedious, time-consuming and can hardly be implemented in on-line mode. A fast and simple quantitative plutonium (IV) analysis using a potentiometric sensor array based on extracting agents is suggested in this study. The response of the set of specially designed PVC-plasticized membrane sensors can be related to plutonium content in solutions simulating real SNF-reprocessing media through multivariate regression modeling, providing 30% higher precision of plutonium quantification than optical spectroscopy.
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Agarwal R, Sharma MK, Noronha DM, Gamare JS, Jayachandran K. Influence of sulfuric acid concentration in the simultaneous voltammetric determination of uranium and plutonium in nuclear fuels. Dalton Trans 2019; 48:7875-7883. [PMID: 31074756 DOI: 10.1039/c9dt00875f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interfacial coupled chemical reaction between U(iv) (formed at the electrode surface) and Pu(iv) (diffuses from the bulk towards the electrode) regenerates U(vi) at the electrode-solution interface and causes enhancement in the U(vi) reduction current, thus creating problems in the simultaneous voltammetric determination of U and Pu. Despite such interference between U(iv) and Pu(iv), the simultaneous voltammetric determination of U and Pu in FBTR Mark-1 fuel samples in sulfuric acid (1 M H2SO4) on a poly(3,4-ethylenedioxythiophene) (PEDOT)-poly(styrenesulfonate) (PSS)-modified glassy-carbon (GC) electrode (PEDOT-PSS/GC) has been reported. However, the reported method is applicable only for FBTR mark-1 fuel samples, in which the ratio [Pu]/[U] > 2 is always maintained. For nuclear samples having [Pu]/[U] < 2 (e.g., PFBR fuel), the simultaneous voltammetric determination of U and Pu is extremely challenging. Herein, we report a modified version of the earlier method for the simultaneous determination of U and Pu in nuclear samples ((U, Pu)C and (U, Pu)O2), irrespective of the [Pu]/[U] ratio. The effect of acidity (H2SO4 conc.) on the coupled chemical reaction between U(iv) and Pu(iv) was examined. It was observed that an increase in the acidity of H2SO4 minimized the coupled chemical reaction, and at 5 M H2SO4, change in the Pu(iv) concentration did not have any effect on the U(vi) reduction current. The coupled chemical reaction between U(iv) and Pu(iv) ceased at 5 M H2SO4 and hence, the simultaneous voltammetric determination of U and Pu was possible on PEDOT-PSS/GC, irrespective of the [Pu]/[U] ratio in 5 M H2SO4. The method was applied for both (U, Pu)O2 (PFBR) and (U, Pu)C (FBTR) samples and was compared with the well-established biamperometric method. The present method shows accuracy and precision comparable to biamperometry and did not show any interference from the commonly encountered impurities in nuclear samples. Thus, both FBTR and PFBR nuclear fuels having different [Pu]/[U] ratios can be analyzed by the present approach and it is a strong competitor to replace the well-established biamperometric method for routine sample analysis.
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Affiliation(s)
- Rahul Agarwal
- Homi Bhabha National Institute, Mumbai 400 094, India
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Agarwal R, Sharma MK, Jayachandran K, Gamare JS, Noronha DM, Lohithakshan KV. Poly(3,4-ethylenedioxythiophene)-Poly(styrenesulfonate)-Coated Glassy-Carbon Electrode for Simultaneous Voltammetric Determination of Uranium and Plutonium in Fast-Breeder-Test-Reactor Fuel. Anal Chem 2018; 90:10187-10195. [PMID: 30091590 DOI: 10.1021/acs.analchem.8b00769] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Uranium (U) and plutonium (Pu) contents in nuclear materials must be maintained to a definite level in order to get the desired performance of the fuel inside the reactor. Therefore, high accuracy and precision is an essential criterion for the determination of U and Pu. We already reported the voltammetric determination of Pu in the presence of U in fast-breeder-test-reactor (FBTR) fuel samples, but interfacial, coupled chemical reactions between U(IV) and Pu(IV) enhance the peak-current density of U(VI) reduction and thus make voltammetry unsuitable for the quantitative determination of U in the presence of Pu. Thus, developing a voltammetric method for the simultaneous determination of U and Pu is highly challenging. Herein, we report the simultaneous voltammetric determination of U and Pu in 1 M sulfuric acid (H2SO4) on a poly(3,4-ethylenedioxythiophene) (PEDOT)-poly(styrenesulfonate) (PSS)-modified glassy-carbon (GC) electrode (PEDOT-PSS/GC). The modified electrode shows enhanced performance compared with bare GC electrodes. The peak-current density for U(VI) reduction is enhanced in the presence of Pu(IV), but it attains saturation when [Pu]/[U] in solution is maintained ≥2. Hence, under these circumstances, the variation of Pu concentration no longer influences the U(VI)-reduction peak, and thus the quantitative determination of U in the presence of Pu is possible. No interference is observed from commonly encountered impurities present in FBTR fuel samples. This method shows accuracy and precision comparable to those of the biamperometry method. High robustness, fast analysis, simultaneous determination, reduced radiation exposure to the analyst, and ease of recovery of U and Pu from analytical waste makes it a suitable candidate to substitute the presently applied biamperometry method.
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Affiliation(s)
- Rahul Agarwal
- Homi Bhabha National Institute , Mumbai 400 094 , India.,Fuel Chemistry Division , Bhabha Atomic Research Centre (BARC) , Trombay, Mumbai 400 085 , India
| | - Manoj K Sharma
- Homi Bhabha National Institute , Mumbai 400 094 , India.,Fuel Chemistry Division , Bhabha Atomic Research Centre (BARC) , Trombay, Mumbai 400 085 , India
| | - Kavitha Jayachandran
- Homi Bhabha National Institute , Mumbai 400 094 , India.,Fuel Chemistry Division , Bhabha Atomic Research Centre (BARC) , Trombay, Mumbai 400 085 , India
| | - Jayashree S Gamare
- Fuel Chemistry Division , Bhabha Atomic Research Centre (BARC) , Trombay, Mumbai 400 085 , India
| | - Donald M Noronha
- Fuel Chemistry Division , Bhabha Atomic Research Centre (BARC) , Trombay, Mumbai 400 085 , India
| | - Kaiprath V Lohithakshan
- Fuel Chemistry Division , Bhabha Atomic Research Centre (BARC) , Trombay, Mumbai 400 085 , India
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Guin SK, Ambolikar AS, Kamat JV. Electrochemistry of actinides on reduced graphene oxide: craving for the simultaneous voltammetric determination of uranium and plutonium in nuclear fuel. RSC Adv 2015. [DOI: 10.1039/c5ra09892k] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Schematic representation of the interference of Pu(iv) in the voltammetric determination of U in a mixed U–Pu solution in 1 M H2SO4.
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Affiliation(s)
- Saurav K. Guin
- Fuel Chemistry Division
- Bhabha Atomic Research Centre
- Mumbai-400 085
- India
| | | | - J. V. Kamat
- Fuel Chemistry Division
- Bhabha Atomic Research Centre
- Mumbai-400 085
- India
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