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Development of a selective Americium SeparationProcess by Liquid-Liquid Extraction

C. Marie, M.-T. Duchesne, E. Russello, P. Kaufholz, A. Wilden, G. Modolo,N. Boubals, M. Miguirditchian

To cite this version:C. Marie, M.-T. Duchesne, E. Russello, P. Kaufholz, A. Wilden, et al.. Development of a selec-tive Americium Separation Process by Liquid-Liquid Extraction. 250th ACS National Meeting andExposition, Aug 2015, Boston, United States. �cea-02509689�

Development of a selective Americium Separation

Process by Liquid -Liquid Extraction

ACS NATIONAL MEETING & EXPOSITION 17th August 2015 Boston, US

C. Marie, M.-T. Duchesne, E. Russello, P. Kaufholz, A. Wilden, G. Modolo, N. Boubals, M. Miguirditchian

CEA Marcoule, Nuclear Energy Division, Radiochemistry & Processes Department, France

| PAGE 1CEA | July 8, 2015

0,1

1

10

100

1000

10000

10 100 1000 10000 100000 1000000

Temps (années)

Rad

ioto

xici

té r

elat

ive

Relative radiotoxicity

U ore

Time (years)

Heterogeneousrecycling

U Pu

R

U

AmFP,Cm

S PUREX+

EXAm

R = reactor S = separation FP = fission products

Final waste

Recycling Am alone� waste lifetime and radiotoxicity

� long term waste heat power � save repository resource

With Am recycling, reduction of the repository surface by a factor up to 8

INTRODUCTION

HLW: 1200 haHLW: 160 ha

Am

rec

yclin

g

Deep Geological Repository

C. Poinssot, C. Rostaing, P. Baron, D. Warin, B. Boullis Procedia Chem. 7, 358–366 (2012).C. Poinssot, C. Rostaing, S. Grandjean, B. Boullis, Procedia Chem. 7, 349–357 (2012).

MAs sep.

0.86 0.88 0.90 0.92 0.940.01

0.1

1

10

100

no TEDGA 50 mM TEDGA

D(A

n, L

n)

1/r (Α−1)0.86 0.88 0.90 0.92 0.94

0.01

0.1

1

10

100

no TEDGA

D(A

n, L

n)

1/r (Α−1)

| PAGE 3

Am/Cm Separation

EXAm Liquid/Liquid Extraction ProcessSelective Recovery of Americium alone from a

PUREX raffinate (already cleared from U, Pu and Np).

*M.-C. Charbonnel et al., Procedia Chem. 2012, 7, 20–26.**V. Pacary et al., Procedia Chem. 2012, 7, 328–333.

AmCm

[HDEHP]=0,3M + [DMDOHEMA]=0,6M dans TPH[HNO3]=5M

Extractants alone � very low Am/Cm selectivity (SFAm/Cm = 1.6)

with TEDGA � SFAm/Cm = 2.5

LaNd

Sm Eu

AmCm

Y. Sasaki, JAEA

ON

O

N

O

TEDGA HNO3 4-6 mol/L

AmCm

La, Ce, Pr, Nd,Sm, Eu, Gd, YFe, Mo

Zr, Pd, RuCs, Sr, Ba, Rh, …

P

OH

O

O

O

ON

O

N

O

Complex Chemistry

Org. Phase: Ternary complexes Ln(HDEHP)x(DMDOHEMA)y J. Muller Thesis

Aq. Phase: Ln(TEDGA)n3+ (n=1,2,3) Stability

constants (Ln, Am)*

� Ln(TEDGA)n(D)y in the Org. Phase (n= 1,2)

Cm, Sm, Eu, Gd, Y, Zr, Ru+ Pd

Ln Fe

CX Ln Strip.

Am

BX Am Strip.

TEDGA Oxalic Acid HNO3 1M

Mo TEDGA Citric Acid

pH 3 (NaOH)

Am , La, Ce, Pr, Nd, Mo, Fe, Ru, TEDGA

DMDOHEMA 0.6M + HDEHP 0.3M, TPH

AX Am Extraction AS Cm Scrubbing

BS Ln Scrub.

LS Mo Strip.

1 16 1 16

Feed HNO3

TEDGA

HNO3

TEDGA

DTPA Malonic acid pH 2.5

NaOH

LX ReEx. Am

pH Control

HEDTA

EXAmC. Marie, et al. Proceedings ISEC, 105-110(2014)

Axis of improvment:� Lower partitionning of the ligand

� Complexing agent with higher Am/Cm selectivity

� Complexing agent with both Am/Cm AND Am/Ln selectivity| PAGE 4

Cold and spiked tests

Hot test

Oxalic co-conversion and U-Am oxide

fabrication

Demonstration: Hot test in ATALANTE April 2010

Objective Now: Concentration of the PUREX raffinate(x3) to improve process compactness

� Hot Test Dec. 2015

2 3 4 5 6

Synthesis of new TEDGA Analogs

NO

N

O O

Spacer

Inversion of selectivity

High affinity with extractants in the organic phase

Lipophilicity

NO

N

O O

N carbon atoms

SFAm/Cm

3-

2-

1-

Loss of selectivity and affinity

TEDGA = best compromise between selectivity and

partitionning

S. Chapron PhD

S. Chapron et al. SXIX (33) 236-248, 2015

0.86 0.88 0.90 0.92 0.94 0.960.01

0.1

1

10

Ce

244-Cm

Without Ligand TPAEN 10mM

D1/r (A-1)

241-Am

La

0.86 0.88 0.90 0.92 0.94 0.960.01

0.1

1

10

Ce

241-Am

244-Cm

244-Cm

Without Ligand TPAEN 10mM

D1/r (A-1)

241-Am

La

TODGA / TPAEN SYSTEM

| PAGE 6

NN

NN

NN

HOOC

COOH

COOH

HOOC

TPAEN

TPAEN

TPAEN = Am stripping agent

Solvent = 0.2M TODGA + 5% vol. octanol in TPH1) Ln + Am and Cm loading at 1M HNO3

+ 241Am, 244Cm

2) Stripping: TPAEN 10 mM at pH 1

Stirring 30min at 25°C

SF(La/Am) = 3.7SF(Cm/Am) = 3.4

Element La Ce Pr Nd Sm Eu Gd Y total[ ] mmol/L 3.8 0.35 0.29 1.5 8.3 2.1 1.7 1.6 20

� Light Ln/Am + Cm/Am separation� Low solubility of TPAEN (2.5 mM in HNO3 0.1M)

TODGA

+

0 5 10 15 20 25 30 35 400.01

0.1

1

10

AmLa

Ce

Eu

D(Eu) D(152-Eu) D(Ce) D(241-Am) D(244-Cm) D(139-Ce) D(La)

[Ln]ini,org

mM

D

Cm

EFFECT OF TPAEN AND L n CONCENTRATIONS

6 octobre 2015| PAGE 7

+ Ln data by ICP-AES

0 2 4 6 8 100.01

0.1

1

10

[TPAEN] mM

D(241-Am) D(244-Cm) D(152-Eu) D(Eu) D(Ce) D(La)

D

No effect of TPAEN concentration on Ln distribution (at this acidity, pHéq=0.8)

Separation La/Am more limiting than Cm/Am

SFLn/Am � with [TPAEN]

Experimental Conditions:

• Solvent = 0.2M TODGA + 5% vol. octanol in TPH , loaded with Ln (from La to Gd) 241Am, 244Cm, 152 Eu, 139Ce traces at 1M HNO3

• Stripping:

TPAEN at pH1 , Stirring 30min at 25°C

6 octobre 2015

No effect of Ln concentration on Ln distribution � far from saturation of the solvent

SFLn/Am � with [Ln] (strong dependance)

It is not possible to separate Am from light Ln if [Ln] > 15 mM[Ln] = 25 mM [tpaen] = 2.5 mM

| PAGE 8

MACRO Am EXPERIMENTS

Experimental conditions

• Solvent = 0.2M TODGA + 5% vol. octanol in TPH

• Loaded with Ln (up to 20 mM), 241Am (up to 2 mM), 244Cm 7 µM (at 1M HNO3)

• Stripping: TPAEN at pH1 Stirring 30min at 25°C

Parameters studied: [Ln], [Am], [TPAEN], Temp.

Results

Important complexation capacity of Am

�[TPAEN]/[Am]Aq = 2

Slight decrease of SFCm/Am when [241Am] �

Slight increase of SFCm/Am when [TPAEN] �

SFLn/Am � with [Ln] (strong dependance)

SF(La/Am) � with [TPAEN] and Temperature

0

2

4

6

8

10

0.05

0.50

5.00

0.0 1.0 2.0

D(A

m, C

m)

[Am]ini, org (mM)

D(Am) D(Cm)SF(Cm/Am)

Effect of Am concentration

0

2

4

6

8

10

0 4 8

SF

(Cm

/Am

)

[TPAEN] (mM)

TPAEN

P. Kaufholz, Jülich

0.00.51.01.52.02.53.03.54.04.55.0

0 10 20 30 40

SF

[Ln]ini, org mM

Effect of Ln concentration

SF(La/Am)

SF(Cm/Am)

1mM Am

Tracer experiment

SF = 1

2.5 mM TPAEN

[Ln] = 15 mM[Am] = 1 mM

2.5 mM TPAEN[Ln] = 15 mM

| PAGE 9

BATCH KINETICS AND EFFECT OF TEMPERATURE P. Kaufholz

T (°°°°C) SF(Cm/Am) SF(Ce/Am)

8 3.5 2.2

14 4.7 3.0

25 4.0 4.7

44 3.6 7.1

Org: 0.2 mol/L TODGA in TPH + 5 vol.-% 1-octanol loaded with 241Am, 244Cm, 152Eu and 139Ce tracersAq: 2.5 mmol/L TPAEN in HNO3 at pHeq=0.730 min. mixing; 3 min centrifugation

Results:Strongly exothermic extraction system

Different slopes for Ln and An but similar within the group

Separation factors are influenced by temperature

Kinetics of An(III) significantly slower than Ln

Faster Am stripping at high TemperatureSFCe/Am ���� with Temperature

Org.: 0.2 M TODGA in TPH + 5 %vol. 1-octanol

loaded with lanthanides and tracers

Aq.: 2.5 mM TPAEN in HNO3 at pHeq~1

Mixer blade speed: 2150 rpm

COMPLEXATION STUDIES N. Boubals, P. Guilbaud (LILA)

6 octobre 2015

18 additions of 2 µL [TPAEN] 10 mM in [Eu] 2 mM matrice HNO3 0.1M

Eu TPAEN

baselinedilutionreaction

Calorimetry25 °C

Complexation constants

Endothermic complexation reaction

logβ (Nd-TPAEN) = 4.2 ±±±± 0.1 at 25°°°°C

[Am] = 1.9 E-4M ; [TPAEN] 0 to 2.5 E-4M ; matrice HCl 0.1M [TPAEN]/ [Am] = 1.33

logβ (Am-TPAEN) = 6.1 ±±±± 0.2 at 25°°°°C

[Eu] =1 10-3M and [TPAEN] = 0 to 1.17 10-2M matrice HNO3 0.1M

logβ (Eu-TPAEN) = 2.5 at 25°°°°C 2.4 (KIT)

UV-visible spectrophotometry � complexation constants

Am

TRFLS

Logβ (Cm-TPAEN) = 4.0 at RT 4.3 (KIT)

Ce

EuLa

NdPrSm

0

1

2

3

4

5

6

7

0.85 0.87 0.89 0.91 0.93 0.95

logβ

1/r (ÅÅÅÅ----1111))))

Ce

EuLa

NdPrSm

Am

Nd (UV)

0

1

2

3

4

5

6

7

0.85 0.87 0.89 0.91 0.93 0.95

logβ

1/r (ÅÅÅÅ----1111))))

Ce

EuLa

NdPrSm

Am

CmNd (UV)

Eu (SLRT)

0

1

2

3

4

5

6

7

0.85 0.87 0.89 0.91 0.93 0.95

logβ

1/r (ÅÅÅÅ----1111))))

| PAGE 10

| PAGE 11

CONCLUSION

TODGA + TPAEN

Stripping of Am selectively from Cm and light Ln

Light Ln / Am separation is difficult to achieve at high concentrations of Ln

Perspectives:� Additional data acquisition (CEA + Jülich) to develop a

thermodynamical model

� Spiked test at Jülich in October 2015

� Hot test at ITU on genuine PUREX raffinate

� Complexation studies: NMR, ESI-MS (Jessica Drader)

Am Stripping

Extraction Scrubbing

FeedHNO3 3M

HNO3FP

TODGA 0.2M TPH 5%vol. octanol

Ln Re-Extraction

HNO3 TPAEN pH1

Am

LnAmCm

LnCm

EXAm Process Demonstration of the scientific feasibility of the sole Americium separation from a PUREX raffinate in 1-cyleProcess adapted to a concentrated raffinate (×3) in order to reduce contactors size

Objective now = Recovery of Am for (U,Am)O2 pellets fabrication

� Last step = hot test on a concentrated raffinate in ATLANTE

AcknowledgmentsE. RusselloM.-T. DuchesneV. VanelV. PacaryM. MiguirditchianS. ChapronX. HérèsF. BurdetM.-J. BollesterosS. CostenobleM-C. CharbonnelP. Guilbaud …

A. Geist

G. ModoloA. WildenP. Kaufholz

A. Casnati

S. Bourg

Acknowledgments

THANK YOU FOR YOURATTENTION !

Ken Nash group

| PAGE 14

CEA | July 8, 2015