ANALYTICAL SEPARATIONS GROUP

Transcription

1 ANALYTICAL SEPARATIONS GROUP Megan Bennett, Ashlee Crable, Sherry Faye, Narek Gharibyan, Julie Gostic, and Chris Klug Subgroup Leader: Ralf Sudowe

2 COMMON RESEARCH GOALS Develop better separation schemas for various radioisotopes (Sr, An, Transactinides) in aqueous systems Environmental Basic Science Applications Emergency Response Nuclear Forensics Sorption/Desorption Studies Characterizing various forms of chromatographic separation procedures

3 ENVIRONMENTAL (SHERRY FAYE) Sorption of 241 Am and 233 U to Volcanic Tuff in the Presence of Shewanella oneidensis (MR-1) Objectives: To obtain data on sorption kinetics, equilibrium and fundamental surface interactions of radionuclides to volcanic tuff, commonly found in the Southern Nevada areas of Yucca Mountain and the Nevada Test site. To obtain a better understanding of surface interactions of the Shewanella oneidensis (MR-1) culture with tuff and radionuclides.

4 RESULTS 233 U Sorption in the Presence of Shewanella Tuff Surface Morphology using SEM % sorbed vs time % sorbed Time (h) U tuff no tuff 10^4 cells/g 10^6 cells/g 10^8 cells/g 10^10 cells/g

5 ENVIRONMENTAL (ASHLEE CRABLE) Developing more efficient separation methods for Sr and Actinides in various environmental matrices Problem Statement The current analytical methods that exist for determining total strontium contamination in various matrices are greatly influenced by the presence of other matrix constituents such as calcium and phosphates. This presents a particular problem for determining total deposition in bone (hydroxyapatite). Preliminary Objective To determine the separation efficiency of 90 Sr using vacuum-assisted extraction chromatography (Sr Spec resin cartridges) in the presence of Ca 2+

6 RESULTS Separation of Sr 2+ in the presence of Ca 2+ % Recovery LOAD RINSE STRIP Fraction "Sr" "Sr + Bone"

7 BASIC SCIENCE APPLICATIONS (MEGAN BENNETT AND JULIE GOSTIC) Chemical characterization of transactinides elements 104 and 105 Studying the nuclear and chemical properties of the heavy elements or transactinides provides validation of predicted periodic trends and illustrates the importance of relativistic effects as a causality for deviations in periodicity. Reaction Products Target Nucleus Fusion or Projectile Compound Nucleus Figure adapted from presentations by Dawn Shaughnessy and Ken Moody, LLNL Fission Products

8 ELEMENT 104 AND 105 CHEMISTRY Objective Develop separation methods that will allow us to separate a few atoms from a sea of other constituents Analytical Challenges Rapid Large number of exchange steps Highly Selective Continuous process Samples easily prepared for α spec Investigation Using Group IV/V chemical homologs, we can determine which extraction chromatography resins are the best candidates

9 RESULTS Group V Batch Results Using DGA Resin 1e+4 1e+3 Uptake of Pa (V), Ta (V) and Np on DGA Resin in HNO 3 / 0.02 M HF Solution Matrix Ta Pa Np 1e+4 1e+3 Uptake of Pa (V), Ta (V) and Np on DGA Resin in HNO 3 /0.2 M HF Matrix Solution Ta Pa Np 1e+2 1e+2 K' K' 1e+1 1e+1 1e+0 1e+0 1e [HNO 3 ] 1e [HNO 3 ] This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA2344 and partially funded by the Laboratory Directed Research and Development Program at LLNL under project tracking code 08-ERD-030.

10 RESULTS: DGA COLUMN EXTRACTIONS Activity Fraction Strip 2 0 Sample Load Strip 1 Strip 2-1 Strip 2-2 Strip 2-3 Strip 2-4 Strip 2-5 Experimental Fraction 243Am 237Np 233Pa )182Ta (Avg Strip 2-6 Strip 3 Recovery >90% for all radionuclides. Sample Loading: 1.0 M HNO 3 / 0.1 M HF, 1 ml Strip 1 (Pa): 0.4 M HNO 3 /0.2 M HF, 5 ml Strip 2 (Ta): 8M HNO 3 /0.2 M HF, 6 x 5 ml Strip 3: 0.1 M Ammonium Bioxalate, 5 ml

11 BASIC SCIENCE APPLICATIONS (NAREK GHARIBYAN) Objective Separation of curium from americium for neutron capture cross section and isomeric ratio measurements ( 242m+g Am from 241 Am) Challenges 241 Am (n,γ) Investigation IT 242 Am 141 y h β Cm d Am/Cm separation methods with extraction chromatography resins from Eichrom that would not require changing Am (III) oxidation state.

12 RESULTS Effects of various nitrates (LiNO 3, KNO 3, NaNO 3, Al(NO 3 ) 3 ) on Am/Cm separation using TEVA 250 resin: TEVA Resin 200 R R N + NO 3 - k' K Am Cm R CH 3 50 R = C 8 H 17 and C 10 H 21 Trialkyl, methylammonium nitrate Li(NO [LiNO ] 3 3 ) 3

13 RESULTS Acid dependency (HNO 3, HCl) on Am/Cm separation from various resins: TRU Resin 100 C 8 H 17 O O 80 Am Cm P C ibu 60 Ph N k' CMPO ibu [HNO 3 ]

14 BASIC SCIENCE APPLICATIONS (CHRIS KLUG) Project Goal Develop new extraction chromatographic resins for actinide separations based on solvent extraction studies Malonamide ligand systems Attractive ligand family completely incinerable and synthesis does not produce large waste stream. Preliminary Objective Synthesize extraction chromatographic resins based on commercially available resins and benchmark sorption characteristics of in-house resin to commercial resin

15 Extraction Chromatography Resin Development and Testing Objective: Develop and characterize new resin(s) O P O N First tests: TRU-like resins CMPO and TBP coated on a polymer support CMPO O P O O O TBP

16 Extraction Chromatography Resin Development and Testing mg Eu sorbed per gram resin [Eu]o = 48.8 ppm Eu sorbed to resin (mg/g) [Eu]o = 9.76 ppm [Eu]o = ppm [Eu]o = ppm [Eu]o = ppm [Eu]o = 117 ppm Eu loading onto TRU-like resin Static conditions were used to determine the resin capacity for Eu -as a homolog for Am Eu breakthrough on a column was measured to determine the dynamic capacity 70 Measured Concentration Static: ~18 mg Eu/g resin Dynamic: ~17 mg Eu/g Fraction number

17 Extraction Chromatography Resin Development and Testing The example resin will also be tested for separating Am from Eu Comparisons to solvent based systems can be made The novel resin will follow the CHNO principle P and other elements can make incineration troublesome Dw Europium Solution Mixed Lanthanide Solution [HNO3]

18 EMERGENCY RESPONSE (JULIE GOSTIC) Sample Preparation Start TEVA TEVA Sr TRU TRU LSC, Alpha/Mass Spectrometry Objective: Develop an automated radioanalysis platform for emergency response efforts. LSC, GPC, MS Separate Cartridge Trays Element-Specific Chemistry Sr Elution System, Sr Resin Sample Introduction Sample Loading and Rinse Am/U Elution System, TRU Resin Pu, Np Th Elution System, TEVA Resin

19 Laboratory Samples (3M HNO 3-1 M Al(NO 3 ) 3, 1.5M Sulfamic and Ascorbic Acids, 3.5M NaNO 2 ) TEVA TRU Disconnect Cartridges TEVA 5 6 Pu Discard Eluent TRU Discard Eluent 4 Am Discard Eluent U 1 Cartridge Pre-treament: 3M HNO 3 6 Elution, 0.1M HCl-0.05M HF-0.03 M TiCl 3 2 Sample Loading 7 Elution, 4M HCl 3 Rinse: 3M HNO 3 8 Th Removal, 4M HCl 0.2 HF 4 Cartridge Waste 9 Elution, 0.1 M Ammonium Bioxalate 5 Rinse: 3 M HNO 3

20 RESULTS Laboratory standards, no counter ions present

21 RESULTS Counter Ion Effects on Extraction Efficiency Pu Efficiency on 275 torr Vac Setting Am Efficiency on 275 torr Vac Setting PO4 Fe Mn Ca Zr 0 PO4 Fe Mn Ca Zr Rinse 1 Rinse 2 Elution 1 Elution 2 Rinse 1 Elution 1 Elution 2

22 CONCLUSIONS Focusing on extraction chromatography protocols Simple, high selectivity, fast kinetics, lower waste stream volume, and automatable Environmental sorption studies Microbial activity should be considered for actinide transport Sequential extraction studies will be conducted to investigate actinide sorption in soils Develop more efficient methods for the isolation/separation of actinides in various matrices

23 CONCLUSIONS Basic Science Applications Develop new resins for actinide separations Develop methods suited for heavy element chemistry Emergency Response Developing an automatable radioanalytical protocol Testing chromatography method on samples containing WGPu particulates Forensics Capabilities Different interpretation of the same data Same samples, different analysis methods Isotopic information