Analytical Separations Group

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
• Basic Science Applications
• Environmental
• Emergency Response
• Nuclear Forensics
• Sorption/Desorption Studies
• Characterizing various forms of chromatographic
  separation procedures

3
Heavy Element Chemistry (Megan Bennett 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.
4
Element 104 105 Chemistry

• Objective
• Analytical Challenges
• Rapid
• Large number of exchange steps
• Highly Selective
• Continuous process
• Samples easily prepared for a spec
• Investigation

Develop separation methods that will allow us to
separate a few atoms from a sea of other
constituents
Using Group IV/V chemical homologs, we can
determine which extraction chromatography resins
are the best candidates
5
Homolog Results

• Group IV Batch Results Using DGA resin

• Group V Batch Results Using DGA Resin

6
DGA Column Extractions
Recovery gt90 for all radionuclides.
7
Analysis of Bone Ash and other matrices(Ashlee
Crable)

• Developing more efficient separation methods for
  Sr and Actinides in various environmental
  matrices
• Problem Statement
• Preliminary Objective

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).
To determine the separation efficiency of 90Sr
using vacuum-assisted extraction chromatography
(SrSpec resin cartridges) in the presence of
Ca2
8
SEM image of bone ash
9
LSC results of spiked bone ash samples
10
Effect of bacteria on sorption of RN to soil
(Sherry Faye)

• Sorption of 241Am and 233U 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.
11
Results

• 233U Sorption in the Presence of Shewanella

• Tuff Surface Morphology using SEM

12
Measurement of neutron capture on Am-241 (Narek
Gharibyan)

• Objective
• Nuclear reactions
• Investigation

Separation of curium from americium for neutron
capture cross section and isomeric ratio
measurements (242mgAm from 241Am)
Am/Cm separation methods with extraction
chromatography resins from Eichrom that would not
require changing Am (III) oxidation state.
13
TEVA resin results

• Effects of various nitrates (LiNO3, KNO3, NaNO3,
  Al(NO3)3, Mg(NO3)2, Ca(NO3)2) on Am/Cm
  separation

14
TRU resin results

• Acid dependency (HNO3, HCl) on Am/Cm separation
  from various resins

15
Automated Rapid Separations(Julie Gostic)
16
(No Transcript)
17
Efficiency and Recovery of samples in Vacuum Box
Laboratory standards, no counter ions present
18

• Counter Ion Effects on Extraction Efficiency

19
Developing a novel extraction resin (Chris Klug)

• Project Goal
• Current Objective
• Secondary Objective

Characterize a new extraction resin for trivalent
actinide separations
Some commercially available resins use
extractants from 1970s, 1960s, and earlier. Use
molecules designed more recently for trivalent
actinide separations in solvent extraction to
maximize extraction properties.
Compare performance of our resins to commercially
available resins and to solvent extraction systems
The novel resin will follow the CHNO rule P
or S can make incineration troublesome
20
Preliminary resins studied

• TRU-like resins CMPO and TBP coated on a
  polymer support

Comparison of commercial and homemade resins with
CMPO and TBP
21
Extraction ChromatographyResin Development and
Testing
Column breakthrough (Eu)

• 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
• Eu and Am have been separated at unequal and
  equal concentrations

Am/Eu Separation in HNO3
22
UNLV Deep BurnRepository Performance Tasks
(You???)

• Project Summary
• SNF Source Term Models
• Based on LWR Fuel
• Cladding Failure
• UO2 Dissolution Kinetic Release Model
• Particle Size
• Surface Area
• Release to Near Field
• TRISO Fuel
• Small oxide particles
• Intrinsic Transport Barrier
• Goal Develop Source Term Model for TRISO fuels

23
Predicting Repository PerformanceWork Planned at
UNLV

• TRISO Repository Behavior
• Actinide Sorption to Graphite
• Determination of Equilibrium Sorption
• Evaluation of Sorption Kinetics
• Degradation of Irradiated Graphite
• Evaluation of Degradation Rate for Irradiated
  Graphite
• Determination of Degradation Mechanisms
• TRISO Fuel Performance Modeling
• Develop Source Term Model
• Sorption-controlled release vs. degradation of
  graphite matrix?
• Equilibrium Sorption vs. Desorption-kinetics
  controlled release?
• Implement Model for Performance Assessment

24
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
• Lessons from bone ash can be applied to cement
  and other construction materials

25
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 WG-Pu particulates
• Forensics Capabilities
• Different interpretation of the same data
• Same samples, different analysis methods
• Isotopic information