Rapid Radiochemical Separations of Americium from Actinides, Mixed Fission Products and Matrix

167 Pages·2015·3.09 MB·English

Rapid Radiochemical Separations of
Americium from Actinides, Mixed
Fission Products and Matrix Elements

A thesis submitted to The University of Manchester for the
degree of Doctor of Philosophy in the Faculty of
Engineering and Physical Sciences

Matthew Alan Higginson

2015

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Table of Contents
1.0 Table of Contents ................................................................................................................. 2
1.1 Table of Figures ................................................................................................................... 6
1.2 Table of Tables .................................................................................................................... 8
1.3 Abbreviations ....................................................................................................................... 9
2.0 Abstract .............................................................................................................................. 12
3.0 Declaration ......................................................................................................................... 13
4.0 Copyright Statement .......................................................................................................... 14
5.0 Acknowledgments.............................................................................................................. 15
6.0 OUTLINE AND AIMS OF PROJECT.............................................................................. 16
6.1 Research Outline ............................................................................................................ 16
6.2 Aims of Project............................................................................................................... 19
6.3 Thesis Structure .............................................................................................................. 20
7.0 LITERATURE SURVEY .................................................................................................. 20
7.1 Scope of Review............................................................................................................. 20
7.2 General Actinide/Lanthanide Chemistry ........................................................................ 21
7.2.1 Lanthanide Chemistry ................................................................................................. 21
7.2.2 Actinide Chemistry ..................................................................................................... 23
7.3 Alpha, Beta and Gamma Decay ..................................................................................... 24
7.4 Nuclear Forensics ........................................................................................................... 25
7.5 Current Actinide Separation Technology ....................................................................... 27
7.5.1 General Principles of Actinide Separation .............................................................. 27
7.5.2 Current Actinide Separation Processes ................................................................... 28
7.5.2.1 Rapid Radiochemical Separations ........................................................................ 31
7.5.3 Methods of Actinide/ Lanthanide Separation .......................................................... 32
7.5.4 Separation of Americium......................................................................................... 35
7.5.5 Soft Anionic Donor Ligands .................................................................................... 38
8.0 References ...................................................................................................................... 43
9.0 Chapter 1 – Rapid Am/Cm separation from nuclear forensic matricies using four triazine
ligands ...................................................................................................................................... 48
9.1 Abstract .......................................................................................................................... 50
9.2 Key Words: .................................................................................................................... 50
9.3 Introduction .................................................................................................................... 51
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9.4 Experimental .................................................................................................................. 53
9.41 Ligand Synthesis....................................................................................................... 54
9.42 Am/Cm Separation from Normal Nuclear Forensics Matrix ................................... 54
9.5 Results and Discussion ................................................................................................... 56
9.51 Ligand Selection ....................................................................................................... 56
9.52 Application of Ligands to Am/Cm Extraction from Simulated Nuclear Forensic
Matrices ............................................................................................................................ 57
9.53 Am/Cm Extraction from Simulated Nuclear Forensic Matrices in the Presence of
Fe, Ca and Al .................................................................................................................... 60
9.54 Am/Cm Extraction from Simulated Nuclear Forensic Matrices by CyMe BTPhen
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without Prior Chromatography ......................................................................................... 63
9.6 Conclusions .................................................................................................................... 65
9.7 Acknowledgements ........................................................................................................ 65
9.8 Notes and References ..................................................................................................... 66
10.0 Appendix to Paper One .................................................................................................... 68
10.1 Method implementation with UTEVA, TEVA and TEVA-TRU and comparison with
DGA resin method for Am (III)/Ln (III) .............................................................................. 68
10.2 Resin investigation results ............................................................................................ 71
10.3 Investigating the effect on the addition of relevant fission and activation products on
the BTPhen separation from a typical nuclear forensic matrix ............................................ 73
10.4 BTPhen separations with Co, Pb and Tc ...................................................................... 75
10.5 Appendix 1 References ................................................................................................ 77
11.0 Chapter 2 - Separation of Am from complex mixtures using a BTPhen extraction
chromatography resin............................................................................................................... 79
11.1 Abstract ........................................................................................................................ 81
11.2 Introduction .................................................................................................................. 82
11.3 Experimental ................................................................................................................ 84
11.31 General Experimental Detail .................................................................................. 84
11.32 Synthesis of PVB-Me4BTPhen .............................................................................. 85
11.33 Conjugation of Me BTPhen derivative 9 to PVBC ................................................ 86
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11.34 Am/Eu separation method ...................................................................................... 87
11.35 Generation of Complex Nuclear Forensic Matrix .................................................. 87
11.4 Results and Discussion ................................................................................................. 88
11.41 Synthesis of PVB- Me BTPhen .............................................................................. 88
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11.42 Initial development of americium extraction using PVB-Me BTPhen .................. 91
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11.43 Americium extraction from nuclear forensic matrix using PVB-Me BTPhen....... 93
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11.44 Variation of acidity and contact time in americium extraction from nuclear
forensic matrix .................................................................................................................. 95
11.5 Conclusions .................................................................................................................. 97
11.6 Acknowledgements ...................................................................................................... 98
11.7 Notes and References ................................................................................................... 98
12.0 Appendix to Paper 2....................................................................................................... 100
12.1 SEM-EDX of polymer 2. ........................................................................................... 100
12.2 SSNMR ..................................................................................................................... 102
12.3 Polymer Disc Work .................................................................................................... 103
12.4 Polymer disk method development ........................................................................... 103
12.5 Adsorption versus covalently bound EC resins………………………………… 103
13.0 Chapter 3 – Am separation using extraction chromatography resins based on adsorped
triazine ligands ....................................................................................................................... 108
13.1 Abstract ...................................................................................................................... 110
13.2 Key Words.................................................................................................................. 110
13.3 Introduction ................................................................................................................ 111
13.4 Experimental .............................................................................................................. 113
13.41 Ligand Synthesis................................................................................................... 114
13.42 Polymer adsorption method .................................................................................. 114
13.43 Initial Am/Eu separation method for triazine EC Resins ..................................... 114
13.44 General Am/Eu separation method for triazine EC Resins .................................. 115
13.45 Generation of Nuclear Forensic/Complex Nuclear Matrix .................................. 115
13.46 General column Am/Eu separation method for triazine EC Resins ..................... 116
13.5 Results and Discussion ............................................................................................... 117
13.51 Resin Preparation .................................................................................................. 118
13.52 Resin loading investigation for AMB-BTPhen/BTBP ......................................... 120
13.53 Matrix elements separations using AMB-BTPhen/BTBP .................................... 121
13.54 K Data for Poly-AMB-BTPhen .......................................................................... 122
D
13.55 K Data for Poly-AMB-BTBP ............................................................................. 124
D
13.6 Conclusions ................................................................................................................ 126
13.7 Acknowledgements .................................................................................................... 127
13.8 Notes and References ................................................................................................. 127
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14.0 Chapter 4 – Synthesis of BTPhen derivatives; effects on solubiliity and Am extraction
................................................................................................................................................ 130
14.1 Abstract ...................................................................................................................... 132
14.2 Introduction ................................................................................................................ 132
14.3 Experimental ............................................................................................................ 132
14.31 Ligand Synthesis................................................................................................... 136
14.32 Solubility screening of BTPhen Ligands .............................................................. 136
14.33 Am/Eu Separations with BTPhen Ligands ........................................................... 136
14.34 Complex matrix separations with benzil-BTPhen ligands ................................... 137
14.35 Generation of Complex Nuclear Matrix ............................................................... 137
14.4 Results and Discussion ............................................................................................... 137
14.41 Ligand Synthesis................................................................................................... 137
14.42 Solubility Testing in Common Reprocessing Solvents ........................................ 138
14.43 Acid Stability of Functionalised BTPhens ........................................................... 141
14.44 Am/Eu Separations by Functionalised BTPhens .................................................. 142
14.45 Complex Nuclear Matrix Separations with Benzil-BTPhens ............................... 145
14.5 Modelling of [AmL]3+ complexes of benzil-BTPhen ligands .................................... 147
14.6 Conclusions ................................................................................................................ 148
14.7 Acknowledgements .................................................................................................... 148
14.8 Notes and references .................................................................................................. 149
15.0 Appendix to section 4 .................................................................................................... 151
15.1 Complex Matrix SF calculated results (by gamma spectroscopy) ..................... 152
Am/Eu
15.2 Triazine ligand experimental data .............................................................................. 152
16.0 Conclusions and recommendations for future work ...................................................... 158
17.0 Methodology Section ..................................................................................................... 162
17.1 Analysis Techniques Applicable to Americium Separation ................................... 162
17.17 References ................................................................................................................ 166

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1.1 Table of Figures and Schemes from all chapters
Chapter 1
Figure 1. AWE americium separation process (Red = Point at which BTPhen separation of
Am may be applied). ................................................................................................................ 18
Figure 2. An example AWE americium separation process using BTPhen. ........................... 19
Figure 3. The f orbitals. ............................................................................................................ 21
Figure 4. Ligands used for actinide separations....................................................................... 29
Figure 5. Types of extraction. .................................................................................................. 34
Figure 6. Calculation of separation factor. ............................................................................... 34
Figure 7. Synthesis of americium. ........................................................................................... 35
Figure 8. Ligands used for americium extraction. ................................................................... 42

Chapter 2
Figure 1. Example of Am separation for a nuclear debris sample. .......................................... 52
Figure 2. Structures of the ligands used in this comparison study........................................... 53
Figure 3. Method for extraction of Am/Cm from complex nuclear forensic sample using
CyMe BTPhen (this work). ..................................................................................................... 59
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Chapter 3
Figure 1 TEVA-TRU-BTPhen separation scheme .................................................................. 69
Figure 2 TEVA-TRU-DGA Separation Scheme ..................................................................... 70
Figure 3 UTEVA-BTPhen separation scheme ......................................................................... 70
Figure 4 TEVA-BTPhen separation scheme............................................................................ 71
Figure 5. Recovery of Ln matrix elements using EC resin separations schemes involving
CyMe BTPhen. ........................................................................................................................ 73
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Figure 6. Potential β/γ and activation products that may require analysis in a nuclear forensic
investigation. ............................................................................................................................ 74
Figure 7. Recovery of relevant fission/neutron activation products from BTPhen matrix
separation from a typical nuclear forensic matrix .................................................................... 75
Figure 8. Matrix element recovery from our devised BTPhen separation method represented
(with errors) in a Periodic Table (without noble gases). All isotopes apart from U, Pu and Np
were 1 mg mL-1 and analysed by ICP-MS. U, Pu and Np were determined after AG1-X8
separation and alpha spectrometry analysis. ............................................................................ 78
Figure 8. Matrix element recovery from our devised BTPhen separation method represented
(with errors) in a Periodic Table (without noble gases). All isotopes apart from U, Pu and Np
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were 1 mg mL-1 and analysed by ICP-MS. U, Pu and Np were determined after AG1-X8
separation and alpha spectrometry analysis. ............................................................................ 78
Figure 1. Structures of CyMe BTPhen 1 and PVB-Me BTPhen 2. ........................................ 84
4 4
Figure 2. Recovery of matrix elements after PVB-Me BTPhen extraction (by ICP-MS). ...... 93
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Figure 3. Variation of Am (III) and Eu (III) extraction by PVB-Me BTPhen with aqueous
4
phase (HCl) acidity .................................................................................................................. 95
Figure 4. Variation of Am (III) and Eu (III) extraction by PVB-Me BTPhen with contact time
4
(N.B. experiments run in triplicate, error calculated from instrument and method error plus
one sigma.) ............................................................................................................................... 96
Figure 1. Representative image of PVB-Me BTPhen 2 ........................................................ 100
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Figure 2. EDX image of polymer 2 with the BSE detector. .................................................. 101
Figure 1. Alpha spectrum from 10 Bq Am/Eu separation by Poly-Aniline-Me -BTPhen
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bonded to an alpha planchette. ............................................................................................... 105
Figure 1. Structures of the ligand 1, 2 and 3 used to synthesise the EC resins used in this
study ....................................................................................................................................... 113
Figure 1: Acid dependencies (K ) of the uptake of Am (III), Ln (III) and FP/Matrix elements
D
on AMB-BTPhen at 0.1-5 M HNO , values determined by ICP-MS and gamma spectroscopy
3
(no errors >2.0% from raw data)............................................................................................ 122
Figure 2: Acid dependencies (K ) of the uptake of Ln (III) and FP/Matrix elements on AMB-
D
BTPhen at 0.1-5 M HNO , values determined by ICP-MS and gamma spectroscopy (no
3
errors >2.0% from raw data). ................................................................................................. 123
Figure 3: Acid dependencies (K ) of the uptake of Am (III), Ln (III) and FP/Matrix elements
D
on AMB-BTBP at 0.1-5 M HNO , values determined by ICP-MS and gamma spectroscopy
3
(no errors >2.0% from raw data)............................................................................................ 124
Figure 4: Acid dependencies (K ) of the uptake of Ln (III) and FP/Matrix elements on AMB-
D
BTBP at 0.1-5 M HNO , values determined by ICP-MS and gamma spectroscopy (no
3
errors >2.0% from raw data). ................................................................................................. 125
Scheme 1. Synthesis of istain-BTPhens. Reagents: (i) diketone, Et N, THF, Δ, <72 h. ....... 137
3
Scheme 2. Synthesis of benzil-BTPhens. Reagents: (i) diketone, Et3N, THF, Δ, <72 h. ..... 138
Scheme 3: Synthesis of aliphatic (and indan) BTPhens. Reagents: (i) diketone, Et N, THF, Δ,
3
<72 h. ..................................................................................................................................... 138

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1.2 Table of Tables
Chapter 1
Table 1: Recoveries of eluted matrix elements from AG1-X8 column chromatography from
analysis by alpha spectrometry and ICP-MS. .......................................................................... 58
Table 2: Recoveries of eluted matrix elements for AG1-X8 column chromatography/triazine
ligand separation from analysis by alpha spectrometry, gamma spectroscopy and ICP-MS.. 60
Table 3a and 3b: Recoveries of eluted matrix elements for high Al and high Ca from AG1-X8
column chromatography from analysis by alpha spectrometry, gamma spectroscopy and ICP-
MS.. .......................................................................................................................................... 62
Table 4: Recoveries of eluted matrix elements for high Al/Ca/Fe initial CyMe BTPhen (10
4
mM, 90 min) separation of nuclear forensic matrix, analysis by alpha spectrometry, gamma
spectroscopy and ICP-MS........................................................................................................ 64
Table 1. Am/Eu recoveries (by gamma spectroscopy) for the Am and Ln fractions from each
separation method, N/D is given as a value if the recovery was determined to be less than 1%
and the error being larger than or equal to the net area of the peak. ........................................ 72
Table 2. Pu, Np and U recoveries calculated by alpha spectrometry for the four separation
methods with associated errors ................................................................................................ 72
Table 3: Pb and Co recoveries from a BTPhen Am separation determined by ICP-MS), Tc
recovery determined by liquid scintillation counting of aqueous phase before and after
separation with 10 mM CyMe BTPhen. .................................................................................. 76
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Chapter 2
Table 1. Recoveries of Am (III)/Eu (III) from PVB-Me BTPhen 2 extraction of Am (III)/Eu
4
(III) matrix (N.B. experiments run in triplicate, error calculated from instrument and method
error plus one sigma.) .............................................................................................................. 92
Table 2. Recoveries of Am (III)/Eu (III) from PVB-Me BTPhen 2 extraction of nuclear
4
forensic matrix (N.B. experiments run in triplicate, error calculated from instrument and
method error plus one sigma.) ................................................................................................. 94
Table 3. Recoveries of U, Np, Pu after PVB-Me BTPhen 2 extraction and AG1-X8
4
chromatography of nuclear forensic matrix , determined by alpha spectrometry (N.B. error
calculated from instrument and method error plus one sigma.)............................................... 94
Chapter 3
Table 1: Preliminary amberlite polymer Am/Eu separation data, determined by gamma
spectroscopy against a known activity standard in the same geometry ................................. 119
Table 2: Am/Eu recoveries from w/w loading AMB-BTPhen/BTBP 15 min polymer
separations (after back stripping) determined by gamma spectroscopy ................................ 120

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Chapter 4
Table 1. Solubilities of isatin- (and indan) BTPhens in industrially relevant solvents .......... 139
Table 2: Solubilities of benzil-BTPhens in industrially relevant solvents. ............................ 140
Table 3: Solubilities of aliphatic BTPhens in industrially relevant solvents. ........................ 141
Table 4: SF for isatin-BTPhens, determined by gamma spectroscopy. ......................... 142
Am/Eu
Table 5: SF for aliphatic BTPhens, determined by gamma spectroscopy. .................... 143
Am/Eu
Table 6: SF for benzil-BTPhens, determined by gamma spectroscopy. ........................ 144
Am/Eu
Table 7: Percentage recovery for matrix elements from separation of complex matrix using
benzil-BTPhen, determined by ICP-MS (samples run in triplicate, error calculated from
instrument error plus one sigma). .......................................................................................... 146
Table 8: Calculated additional electron population on triazine nitrogens calculated by DFT
(Gaussian 09, B3LYP) ........................................................................................................... 148
Table 1. SF from separation of complex matrix using benzil-BTPhen ligands ............. 152
Am/Eu
1.3 LIST OF ABBREVIATIONS
α-HIBA α-Hydroxyisobutyric acid
AWE Atomic Weapons Establishment
BTBP Bis-triazinylbipyridines
BTP Bis-triazinylpyridines
BTPhen 2,9-Bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-
1,10-phenanthroline (CyMe BTPhen)
4
CA-BTP Bis-2,6-(5,6,7,8-tetrahydro-5,9,9-trimethyl-5,8-methano-
1,2,4-benzotriazin-3-yl)pyridine
CA-BTPhen 2,9-Bis(5,9,9-trimethyl-5,6,7,8-tetrahydro-5,8-
methanobenzo[e][1,2,4]triazin-3-yl)-1,10-phenanthroline
CHON Carbon, hydrogen, oxygen, nitrogen
CMPO Carbamoyl methyl phosphine oxide
DEHSO Di-(2-ethylhexyl)sulfoxide
DIAMEX Diamine extraction
DOSY Diffusion ordered NMR spectroscopy
DOWEX Dow® Extraction
DTPA Diethylenetriamine-N,N,N',N'',N''-pentaacetic acid
EDTA Ethylenediaminetetraacetic acid
EXAFS Extended X-ray absorption fine structure
GANEX Group actinide extraction
HDEHP Di-(2-ethylhexyl)phosphoric acid
HLLW High level liquid (radioactive) waste
HPLC High pressure/high performance liquid chromatography
ICP-MS/OES Inductively coupled plasma mass spectrometry/optical emission
spectroscopy
MALDI Matrix assisted laser desorption ionisation
NMR Nuclear magnetic resonance
n-PrBTP 2,6-Di(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine
PUREX Plutonium uranium extraction
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PVBC Polyvinylbenzyl chloride
PVC Polyvinyl chloride
RTIL Room temperature ionic liquids
SANEX Selective actinide extraction
SIMS Secondary ion mass spectrometry
TALSPEAK Trivalent actinide-lanthanide separation by phosphorus reagent
extraction from aqueous complexes
TBDMS Tert-butyldimethylsilyl
TBP Tri-n-butyl phosphate
TERPY Terpyridine
TODGA Tetraoctyl diglycolamide
TPTZ 2,4,6-Tripyridyl-s-triazine
TRLFS Time-resolved laser fluorescence spectroscopy
TRPO Tertiary R group phosphine oxide
TRUEX Trans-uranium elements extraction
UTEVA Uranium tetravalent extraction
UV-VIS-NIR Ultra-violet-visible-near infra red spectroscopy
XRD X-ray diffraction
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