ANALYTICAL SEPARATIONS GROUP

Megan Bennett, Ashlee Crable, Sherry Faye,

Narek Gharibyan, Julie Gostic, and Chris Klug

Subgroup Leader: Ralf Sudowe

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

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.

Reaction Products

Target Nucleus

Projectile Compound Nucleus

Fission ProductsFigure adapted from presentations by Dawn Shaughnessy and Ken Moody

Hot Fusion

or

Element 104 & 105 Chemistry

Objective

Analytical Challenges Rapid Large number of exchange steps Highly Selective Continuous process Samples easily prepared for α 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

Homolog Results

Group IV Batch Results Using DGA resin

Group V Batch Results Using DGA Resin

DGA Column Extractions

Sample Loading: 1.0 M HNO3/ 0.1 M HF, 1 mLStrip 1 (Pa): 0.4 M HNO3/0.2 M HF, 5 mL

Strip 2 (Ta): 8M HNO3/0.2 M HF, 6 x 5 mLStrip 3: 0.1 M Ammonium Bioxalate, 5 mL

Recovery >90% for all radionuclides.

MS-5 Fractional Radionuclide Activity Distribution

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

SampleLoad

Strip 1 Strip 2-1

Strip 2-2

Strip 2-3

Strip 2-4

Strip 2-5

Strip 2-6

Strip 3

Experimental Fraction

Act

ivit

y F

ract

ion

243Am 237Np 233Pa (182 Ta)Avg

Strip 2

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 (Sr·Spec resin cartridges) in the presence of Ca2+

SEM image of bone ash

LSC Bone Ash Runs (0 - 4 days)

0

100

200

300

400

500

600

700

LOAD RINSE STRIP

CP

M

0.1 M NIST

0.4 M NIST

0.8 M EBON

LSC results of spiked bone ash samples

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.

Results

% sorbed vs time

0102030405060708090

100

0.00 20.00 40.00 60.00 80.00

Time (h)

% s

orbe

d

U-233 + tuff

no tuff

10 4̂ cells/g

10 6̂ cells/g

10 8̂ cells/g

10 1̂0 cells/g

233U Sorption in the Presence of Shewanella

Tuff Surface Morphology using SEM

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

Objective

Nuclear reactions

Investigation

241Am

242Cm

IT

242Am β-

(n,γ) 141 y

16.02 h

162.8 d

Separation of curium from americium for neutron capture cross section and isomeric ratio measurements (242m+gAm from 241Am)

Am/Cm separation methods with extraction chromatography resins from Eichrom that would not require changing Am (III) oxidation state.

TEVA resin results

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

N + NO3-

R

CH3

R

R

R = C8H17 and C10H21

Trialkyl, methylammonium

nitrate0

50

100

150

200

250

0.00 1.00 2.00 3.00 4.00 5.00 6.00

AmCm

k'

[LiNO3]

K’

Li(NO3)3

TRU resin results

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

0

20

40

60

80

100

0.01 0.1 1 101

AmCm

k'

[HNO3]

P

O O

N

CMPO

P

O

OOO

TBP

Automated Rapid Separations(Julie Gostic)

Sr Elution System, Sr ResinSr Elution System, Sr Resin

Am/U Elution System, TRU ResinAm/U Elution System, TRU Resin

Pu, Np Th Elution System, TEVA Pu, Np Th Elution System, TEVA ResinResin

Sample Sample IntroductionIntroduction

Sample Sample Loading and Loading and RinseRinse

Separate Cartridge Separate Cartridge TraysTrays

Element-Specific Element-Specific Chemistry Chemistry

Start

TEVA TEVA

TRU TRUSr

LSC, GPC, MSLSC, GPC, MS

LSC, Alpha/Mass LSC, Alpha/Mass Spectrometry Spectrometry

Sample Preparation

http://www.jkem.com/spe.html

Laboratory Samples(3M HNO3-1 M Al(NO3)3, 1.5M Sulfamic and Ascorbic Acids, 3.5M NaNO2)

Discard Eluent

Am

12

3

4

TRU

TEVA

Discard Eluent

Discard Eluent

5

6

Pu6

5

TEVADisconnect Cartridges

9

7

79

8U

TRU

8

Th Removal, 4M HCl – 0.2 HF3

2

1

Sample Loading

Rinse: 3M HNO3

Cartridge Pre-treament: 3M HNO3

7 Elution, 4M HCl

8

9 Elution, 0.1 M Ammonium Bioxalate4 Cartridge Waste

5 Rinse: 3 M HNO3

6 Elution, 0.1M HCl-0.05M HF-0.03 M TiCl3

Laboratory standards, no counter ions present

Efficiency and Recovery of samples in Vacuum Box

Counter Ion Effects on Extraction Efficiency

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.

N N

O O

R1

R2

R3

R4R5

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

Preliminary resins studied “TRU-like” resins – CMPO and TBP coated on a

polymer supportP

O O

N

CMPO

P

O

OOO

TBP

40

50

60

70

80

90

100

7001700270037004700

Wavenumber (cm^-1)

Tra

nsm

issi

on

(%

)

Comparison of commercial and homemade resins with CMPO and TBP

Extraction ChromatographyResin Development and Testing

Eu loading onto TRU-like resin

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60

Fraction number

Mea

sure

d

Co

nce

ntr

atio

n

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

TRU Like resin Column Elution - Am/Eu Separation using 0.1 M HNO3

-0.2

0.2

0.6

1

1.4

1.8

0 50 100 150Fraction Number

pp

m E

u in

el

ute

d f

ract

ion

(pu

rple

d

iam

on

d)

-10

15

40

65

90

115

cpm

Am

-241

in

elu

ted

fra

ctio

n(p

ink

squ

are)

Column breakthrough (Eu)

Am/Eu Separation in HNO3

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

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

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

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