Radiochemistry Annex

EMSL’s Radiochemistry Annex is designed to accelerate scientific discovery and deepen the understanding of the chemical fate and transport of radionuclides in terrestrial and subsurface ecosystems.

The annex offers experimental and computational tools uniquely suited for actinide chemistry studies. The spectroscopic and imaging instruments at this facility are ideally designed for the study of contaminated environmental materials, examination of radionuclide speciation and detection of chemical signatures. The annex houses nuclear magnetic resonance instruments and surface science capabilities, such as X-ray photoelectron spectroscopy, electron microscopy, electron microprobe, transmission electron microscopy and scanning electron microscopy. Annex users also have access to expert computational, modeling and simulation resources and support.

The annex is an environment where multiple experimental approaches are encouraged. Investigating problems at an integrated, cross-disciplinary level encourages holistic understanding, which ultimately provides policy makers the information they need to make sound remediation choices.

Like all of EMSL's capabilities, those housed in the annex are available to the scientific community at typically no cost for openly published research. Scientists gain access to instruments and collaborate with onsite microscopy experts through a peer-reviewed proposal process. Research conducted in the annex requires special information and handling. Prior to submitting a proposal, potential users should familiarize themselves with the guidance for using and shipping radioactive material to the annex.

Radiochemistry Annex videos on EMSL's YouTube channel - Learn about the individual instruments in the Radiochemistry Annex and specifically how they advance subsurface and terrestrial ecosystem science.

And don't miss the virtual tour of our Radiochemistry Annex.

Additional Information:

Instruments

Housed in EMSL's Radiochemistry Annex, the field emission electron microprobe (EMP) enables chemical analysis and imaging of radionuclides with high...
Custodian(s): Bruce Arey
EMSL's Digital Instruments Radiological BioScope™ Atomic Force Microscope (AFM) allows radiological samples to be examined in fluids or air with...
Custodian(s): Kevin M. Rosso
Research applications Samples containing paramagnetics Soils (SOM and NOM) Metal oxide materials for catalysis applications Researchers may operate...
Custodian(s): Nancy Washton, Sarah D Burton
EMSL's Bruker wide-bore 750 MHz solids/liquids/imaging spectrometer is dedicated to radiological and environmental samples. Housed in the EMSL...
Custodian(s): Nancy Washton
The Bruker EMX electron paramagnetic resonance (EPR) spectrometer performs continuous-wave magnetic resonance using electron spins to selectively...
Custodian(s): Eric Walter

Science Highlights

Posted: July 06, 2011
Scientists from Pacific Northwest National Laboratory and Rai Enviro-Chem, LLC, recently published first-ever results that illustrate the importance...

EMSL’s Radiochemistry Annex is designed to accelerate scientific discovery and deepen the understanding of the chemical fate and transport of radionuclides in terrestrial and subsurface ecosystems.

The annex offers experimental and computational tools uniquely suited for actinide chemistry studies. The spectroscopic and imaging instruments at this facility are ideally designed for the study of contaminated environmental materials, examination of radionuclide speciation and detection of chemical signatures. The annex houses nuclear magnetic resonance instruments and surface science capabilities, such as X-ray photoelectron spectroscopy, electron microscopy, electron microprobe, transmission electron microscopy and scanning electron microscopy. Annex users also have access to expert computational, modeling and simulation resources and support.

The annex is an environment where multiple experimental approaches are encouraged. Investigating problems at an integrated, cross-disciplinary level encourages holistic understanding, which ultimately provides policy makers the information they need to make sound remediation choices.

Like all of EMSL's capabilities, those housed in the annex are available to the scientific community at typically no cost for openly published research. Scientists gain access to instruments and collaborate with onsite microscopy experts through a peer-reviewed proposal process. Research conducted in the annex requires special information and handling. Prior to submitting a proposal, potential users should familiarize themselves with the guidance for using and shipping radioactive material to the annex.

Radiochemistry Annex videos on EMSL's YouTube channel - Learn about the individual instruments in the Radiochemistry Annex and specifically how they advance subsurface and terrestrial ecosystem science.

And don't miss the virtual tour of our Radiochemistry Annex.

Additional Information:

Diffusional Motion of Redox Centers in Carbonate Electrolytes .

Abstract: 

Ferrocene (Fc) and N-(ferrocenylmethyl)-N,N-dimethyl-N-ethylammonium bistrifluoromethyl-sulfonimide (Fc1N112-TFSI) were dissolved in carbonate solvents and self diffusion coefficents (D) of solutes and solvents were measured by 1H and 19F pulsed field gradient (PFG) nuclear magnetic resonance (NMR) spectroscopy. The organic solvents were propylene carbonate (PC), ethyl methyl carbonate (EMC) and a ternary mixture that also includes ethylene carbonate (EC). Results from NMR studies over the temperature range of 0-50 °C and for various concentrations (0.25 - 1.7 M) of Fc1N112-TFSI are compared to values of D simulated with classical molecular dynamics (MD). The measured self-diffusion coefficients gradually decreased as the Fc1N112-TFSI concentration increased in all solvents. Since the peaks for the two ions (Fc1N212 and TFSI) are separated in one-dimensional NMR spectra, separate diffusion coefficients could be measured and DTFSI is larger than DFc1N112 in all samples measured. The EC, PC and EMC have the same D in the neat solvent mixture and when Fc is dissolved in EC/PC/EMC at a concentration of 0.2 M, probably due to the interactions between common carbonyl structures within EC, PC and EMC. A difference in D (DPC < DEC < DEMC), and both a higher Ea for translational motion and higher effective viscosity for PC in the mixture containing Fc1N112-TFSI reflect the interaction between PC and Fc1N112+, which is a relatively stronger interaction than that between Fc1N112+ and other solvent species. In the EC/PC/EMC solution that is saturated with Fc1N112-TFSI, we find that DPC = DEC = DEMC and Fc1N112+ and all components of the EC/PC/EMC solution have the same Ea for translational motion, while the ratio DEC/PC/EMC/DFc1N112+ is approximately 3. These results reflect the lack of available free volume for independent diffusion in the saturated solution. The Fc1N112+ transference numbers lie around 0.4 and increases slightly as the temperature is increased in the PC and EMC solvents. The trends observed for D from simulations are in good agreement with experimental results and provide molecular level understanding of the solvation structure of Fc1N112-TFSI dissolved in EC/PC/EMC.

Citation: 
Han KS, NN Rajput, X Wei, W Wang, JZ Hu, KA Persson, and KT Mueller.2014."Diffusional Motion of Redox Centers in Carbonate Electrolytes ."Journal of Chemical Physics 141(10):104509. doi:10.1063/1.4894481
Authors: 
KS Han
NN Rajput
X Wei
W Wang
JZ Hu
KA Persson
KT Mueller
Instruments: 
Volume: 
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Publication year: 
2014

Composition and Interface Analysis of InGaN/GaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography.

Abstract: 

In0.20Ga0.80N/GaN multi-quantum wells grown on [0001]-oriented GaN substrates with and without an InGaN buffer layer were characterized using three-dimensional atom probe tomography. In all samples, the upper interfaces of the QWs were slightly more diffuse than the lower interfaces. The buffer layers did not affect the roughness of the interfaces within the quantum well structure, a result attributed to planarization of the surface of the 1st GaN barrier layer which had an average root-mean-square roughness of 0.177 nm. The In and Ga distributions within the MQWs followed the expected distributions for a random alloy with no indications of In clustering.

Citation: 
Liu F, L Huang, RF Davis, LM Porter, DK Schreiber, SVNT Kuchibhatla, V Shutthanandan, S Thevuthasan, E Preble, T Paskova, and KR Evans.2014."Composition and Interface Analysis of InGaN/GaN Multiquantum-Wells on GaN Substrates Using Atom Probe Tomography."Journal of Vacuum Science and Technology B--Microelectronics and Nanometer Structures 32(5):Article No. 051209. doi:10.1116/1.4893976
Authors: 
F Liu
L Huang
RF Davis
LM Porter
DK Schreiber
SVNT Kuchibhatla
V Shutthanan
S Thevuthasan
E Preble
T Paskova
KR Evans
Volume: 
Issue: 
Pages: 
Publication year: 
2014

Symmetries of migration related segments of all [001] coincidence site lattice tilt boundaries in (001) projections for all

Abstract: 

Utilizing bicrystallography in two dimensions (2D), the symmetries of migration related segments of Coincidence Site Lattice (CSL) boundaries are derived for projections along their [001] tilt axis in grain boundaries of crystalline materials that possess the holohedral point symmetry of the cubic system (i.e. m3m). These kinds of “edge-on” projections are typical for atomic resolution imaging of such tilt boundaries with Transmission Electron Microscopes (TEM). This fact facilitates the visual confirmation of our predictions by recently published Zcontrast scanning TEM investigations [H. Yang et al., Phil. Mag. 93 (2013) 1219] and many other TEM studies.

Citation: 
Moeck P, BW York, and ND Browning.2014."Symmetries of migration related segments of all [001] coincidence site lattice tilt boundaries in (001) projections for all holohedral cubic materials."Crystal Research & Technology 49(9):708-720. doi:10.1002/crat.201400071
Authors: 
P Moeck
BW York
ND Browning
Instruments: 
Volume: 
49
Issue: 
9
Pages: 
708-720
Publication year: 
2014

Behavior of nanoceria in biologically-relevant environments.

Abstract: 

Cerium oxide nanoparticles (CNPs) have gained a considerable attention in biological research due to their anti-oxidant like behaviour and regenerative nature. The current literature on CNPs reports many successful attempts on harnessing the beneficial therapeutic properties in biology. However studies have also shown toxicity effect with some types of CNPs. This review discusses issues associated with the behaviours of CNPs in biological systems and identifies key knowledge gaps. We explore how salient physicochemical properties (size, surface chemistry, surface stabilizers) contribute to the potential positive and negative aspects of nanoceria in biological systems. Based on variations of results reported in the literature, important issues need to be addressed. Are we really studying the same particles with slight variations in size and physicochemical properties or do the particles being examined have fundamentally different behaviours? Are the variations observed in the result of differences in the initial properties of the particles or the results of downstream effects that emerge as the particles are prepared for specific studies and they interact with biological or other environmental moieties? How should particles be appropriately prepared for relevant environmental/toxicology/safety studies? It is useful to recognize that nanoparticles encompass some of the same complexities and variability associated with biological components

Citation: 
Kumar A, S Das, P Munusamy, W Self, DR Baer, DC Sayle, and S Seal.2014."Behavior of nanoceria in biologically-relevant environments."Environmental Science: Nano 1(6):516-532. doi:10.1039/C4EN00052H
Authors: 
A Kumar
S Das
P Munusamy
W Self
DR Baer
DC Sayle
S Seal
Instruments: 
Volume: 
1
Issue: 
6
Pages: 
516-532
Publication year: 
2014

Experimental and Theoretical Studies on the Fragmentation of Gas-Phase Uranyl-, Neptunyl- and Plutonyl-Diglycolamide Complexes.

Abstract: 

Fragmentation of actinyl(VI) complexes UVIO2(L)22+, NpVIO2(L)22+ and PuVIO2(L)22+ (L = tetramethyl-3-oxa-glutaramide, TMOGA) produced by electrospray ionization was examined in the gas phase by collision induced dissociation (CID) in a quadrupole ion trap mass spectrometer. Cleavage of the C-Oether bond was observed for all three complexes, with dominant products being UVIO2(L)(L-86)+ with charge reduction, and NpVIO2(L)(L-101)2+ and PuVIO2(L)(L-101)2+ with charge conservation. The neptunyl and plutonyl complexes also exhibited substantial L+ loss to give pentavalent complexes NpVO2(L)+ and PuVO2(L)+, whereas the uranyl complex did not, consistent with the comparative An 5f-orbital energies and the AnVIO22+/AnVO2+ (An = U, Np, Pu) reduction potentials. CID of NpVO2(L)2+ and PuVO2(L)2+ was dominated by neutral ligand loss to form NpVO2(L)+ and PuVO2(L)+, which hydrated by addition of residual water in the ion trap; UVO2(L)2+ was not observed. Theoretical calculations of the structures and bonding of the AnVIO2(L)22+ complexes using density functional theory reveal that the metal centers are coordinated by six oxygen atoms from the two TMOGA ligands. The results are compared with radiolytic decomposition of TMOGA in solution.

Citation: 
Gong Y, HS Hu, L Rao, J Li, and JK Gibson.2013."Experimental and Theoretical Studies on the Fragmentation of Gas-Phase Uranyl-, Neptunyl- and Plutonyl-Diglycolamide Complexes."Journal of Physical Chemistry A 117(40):10544-10550. doi:10.1021/jp4076977
Authors: 
Y Gong
HS Hu
L Rao
J Li
JK Gibson
Instruments: 
Volume: 
117
Issue: 
40
Pages: 
10544-10550
Publication year: 
2013

Fe/SSZ-13 as an NH3-SCR Catalyst: A Reaction Kinetics and FTIR/Mössbauer Spectroscopic Study.

Abstract: 

Using a traditional aqueous solution ion-exchange method under a protecting atmosphere of N2, an Fe/SSZ-13 catalyst active in NH3-SCR was synthesized. Mössbauer and FTIR spectroscopies were used to probe the nature of the Fe sites. In the fresh sample, the majority of Fe species are extra-framework cations. The likely monomeric and dimeric ferric ions in hydrated form are [Fe(OH)2]+ and [HO-Fe-O-Fe-OH]2+, based on Mössbauer measurements. During the severe hydrothermal aging (HTA) applied in this study, a majority of cationic Fe species convert to FeAlOx and clustered FeOx species, accompanied by severe dealumination of the SSZ-13 framework. The clustered FeOx species do not give a sextet Mössbauer spectrum, indicating that these are highly disordered. However, some Fe species in cationic positions remain after aging as determined from Mössbauer measurements and CO/NO FTIR titrations. NO/NH3 oxidation reaction tests reveal that dehydrated cationic Fe are substantially more active in catalyzing oxidation reactions than the hydrated ones. For NH3-SCR, enhancement of NO oxidation under ‘dry’ conditions promotes SCR rates below ~300 C. This is due mainly to contribution from the “fast” SCR channel. Above ~300 C, enhancement of NH3 oxidation under ‘dry’ conditions, however, becomes detrimental to NOx conversions. The HTA sample loses much of the SCR activity below ~300 C; however, above ~400 C much of the activity remains. This may suggest that the FeAlOx and FeOx species become active at such elevated temperatures. Alternatively, the high-temperature activity may be maintained by the remaining extra-framework cationic species. For potential practical applications, Fe/SSZ-13 may be used as a co-catalyst for Cu/CHA as integral aftertreatment SCR catalysts on the basis of the stable high temperature activity after hydrothermal aging. The authors gratefully acknowledge the US Department of Energy (DOE), Energy Efficiency and Renewable Energy, Vehicle Technologies Office for the support of this work. The research described in this paper was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle.

Citation: 
Gao F, M Kollar, RK Kukkadapu, NM Washton, Y Wang, J Szanyi, and CHF Peden.2015."Fe/SSZ-13 as an NH3-SCR Catalyst: A Reaction Kinetics and FTIR/Mössbauer Spectroscopic Study."Applied Catalysis. B, Environmental 164:407-419. doi:10.1016/j.apcatb.2014.09.031
Authors: 
F Gao
M Kollar
RK Kukkadapu
NM Washton
Y Wang
J Szanyi
CHF Peden
Volume: 
Issue: 
Pages: 
Publication year: 
2015

Ion-induced swelling of ODS ferritic alloy MA957 tubing to 500 dpa.

Abstract: 

In order to study the potential swelling behavior of the ODS ferritic alloy MA957 at very high dpa levels, specimens were prepared from pressurized tubes that were unirradiated archives of tubes previously irradiated in FFTF to doses as high at 110 dpa. These unirradiated specimens were irradiated with 1.8 MeV Cr+ ions to doses ranging from 100 to 500 dpa and examined by transmission electron microscopy. No coinjection of helium or hydrogen was employed. It was shown that compared to several ferritic/martensitic steels irradiated in the same facility, these tubes were rather resistant to void swelling, reaching a maximum value of only 4.5% at 500 dpa and 450°C. In this fine-grained material, the distribution of swelling was strongly influenced by the presence of void denuded zones along the grain boundaries.

Citation: 
Toloczko MB, FA Garner, V Voyevodin, VV Bryk, OV Borodin, VV Melnichenko, and AS Kalchenko.2014."Ion-induced swelling of ODS ferritic alloy MA957 tubing to 500 dpa."Journal of Nuclear Materials 453(1-3):323-333. doi:10.1016/j.jnucmat.2014.06.011
Authors: 
MB Toloczko
FA Garner
V Voyevodin
VV Bryk
OV Borodin
VV Melnichenko
AS Kalchenko
Volume: 
453
Issue: 
Pages: 
323-333
Publication year: 
2014

Fe(II)-catalyzed Recrystallization of Goethite Revisited.

Abstract: 

Results from enriched 57Fe isotope tracer experiments have shown that atom exchange can occur between structural Fe in Fe(III) oxides and aqueous Fe(II) with no formation of secondary minerals or change in particle size or shape. Here we derive a mass balance model to quantify the extent of Fe atom exchange between goethite and aqueous Fe(II) that accounts for different Fe pool sizes. We use this model to reinterpret our previous work and to quantify the influence of particle size and pH on extent of goethite exchange with aqueous Fe(II). Consistent with our previous interpretation, substantial exchange of goethite occurred at pH 7.5 (≈ 90%) and we observed little effect of particle size between nanogoethite (81 x 11 nm) and microgoethite (590 x 42 nm). Despite ≈ 90% of the bulk goethite exchanging at pH 7.5, we found no change in mineral phase, particle size, crystallinity, or reactivity after reaction with aqueous Fe(II). At a lower pH of 5.0, no net sorption of Fe(II) was observed and significantly less exchange occurred accounting for less than the estimated proportion of surface Fe atoms in the particles. Particle size appears to influence the amount of exchange at pH 5.0 and we suggest that aggregation and surface area may play a role. Results from sequential chemical extractions indicate that 57Fe accumulates in extracted Fe(III) goethite components. Isotopic compositions of the extracts indicate that a gradient of 57Fe develops within the goethite with more accumulation of 57Fe occurring in the more easily extracted Fe(III) that may be nearer to the surface. We interpret our particle size, pH, and sequential extraction findings as consistent with the mechanism of interfacial electron transfer and bulk conduction previously proposed to explain the substantial Fe atom exchange observed in goethite in contact with aqueous Fe(II).

Citation: 
Handler R, AJ Frierdich, C Johnson, KM Rosso, B Beard, CM Wang, D Latta, A Neumann, TS Pasakarnis, WAPJ Premaratne, and M Scherer.2014."Fe(II)-catalyzed Recrystallization of Goethite Revisited."Environmental Science & Technology 48(19):11302-11311. doi:10.1021/es503084u
Authors: 
R Hler
AJ Frierdich
C Johnson
KM Rosso
B Beard
CM Wang
D Latta
A Neumann
TS Pasakarnis
WAPJ Premaratne
M Scherer
Volume: 
48
Issue: 
19
Pages: 
11302-11311
Publication year: 
2014

Grain boundary depletion and migration during selective oxidation of Cr in a Ni-5Cr binary alloy exposed to high-temperature

Abstract: 

High-resolution microscopy of a high-purity Ni-5Cr alloy exposed to 360°C hydrogenated water reveals intergranular selective oxidation of Cr accompanied by local Cr depletion and diffusion-induced grain boundary migration (DIGM). The corrosion-product oxide consists of a porous, interconnected network of Cr2O3 platelets with no further O ingress into the metal ahead. Extensive grain boundary depletion of Cr (to <0.05at.%) is observed typically 20–100 nm wide as a result of DIGM and reaching depths of many micrometers beyond the oxidation front.

Citation: 
Schreiber DK, MJ Olszta, and SM Bruemmer.2014."Grain boundary depletion and migration during selective oxidation of Cr in a Ni-5Cr binary alloy exposed to high-temperature hydrogenated water."Scripta Materialia 89:41-44. doi:10.1016/j.scriptamat.2014.06.022
Authors: 
DK Schreiber
MJ Olszta
SM Bruemmer
Instruments: 
Volume: 
Issue: 
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Publication year: 
2014

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