Development of a selective Americium Separation Process by Liquid-Liquid Extraction

HAL Id: cea-02509689

https://hal-cea.archives-ouvertes.fr/cea-02509689

Submitted on 17 Mar 2020

HAL is a multi-disciplinary open access

archive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Development of a selective Americium Separation

Process 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 and Exposition, 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 1 CEA | July 8, 2015

0,1 1 10 100 1000 10000 10 100 1000 10000 100000 1000000 Temps (années) R a d io to x ic it é r e la ti v e Relative radiotoxicity

U ore

Time (years)

Heterogeneous

recycling

U Pu

R

U

Am

FP,

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 ha HLW: 160 ha

A

m

r

ec

yc

lin

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).

0.86 0.88 0.90 0.92 0.94 0.01 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 Process

Selective 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.

Am Cm

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

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

with TEDGA SF_Am/Cm= 2.5

La Nd Sm Eu Am Cm Y. Sasaki, JAEA O N O N O TEDGA _HNO 3 4-6 mol/L AmCm

La, Ce, Pr, Nd,Sm, Eu, Gd, Y Fe, Mo Zr, Pd, Ru Cs, Sr, Ba, Rh, … P OH O O O O N 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)*

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 1 6 Feed HNO₃ TEDGA HNO₃ TEDGA DTPA Malonic acid pH 2.5 NaOH LX ReEx. Am pH Control HEDTA

EXA

m

C. 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

2

3

4 5 6

Synthesis of new TEDGA Analogs

N O N

O O

Spacer

Inversion of selectivity

High affinity with

extractants in the organic phase

Lipophilicity

N O N O O N carbon atoms SF_Am/Cm 3- 2- 1-Loss of selectivity and affinity

TEDGA = best compromise

between selectivity and

partitionning

S. Chapron PhD

0.86 0.88 0.90 0.92 0.94 0.96 0.01 0.1 1 10 Ce 244-Cm Without Ligand TPAEN 10mM D 1/r (A-1) 241-Am La 0.86 0.88 0.90 0.92 0.94 0.96 0.01 0.1 1 10 Ce 241-Am 244-Cm 244-Cm Without Ligand TPAEN 10mM D 1/r (A-1) 241-Am La

TODGA / TPAEN SYSTEM

| PAGE 6 N N N N N N HOOC COOH COOH HOOC TPAEN

TPAEN

TPAEN = Am stripping agent

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

1) Ln + Am and Cm loading at 1M HNO₃

+ 241_Am, 244_Cm 2) Stripping: TPAEN 10 mM at pH 1 Stirring 30min at 25°C

SF(La/Am) = 3.7

SF(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 HNO

₃

0.1M)

TODGA

0 5 10 15 20 25 30 35 40 0.01 0.1 1 10 Am La 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 10 0.01 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, pH_éq=0.8)

Separation La/Am more limiting than Cm/Am SF_Ln/Am with [TPAEN]

Experimental Conditions:

• Solvent = 0.2M TODGA +

5% vol. octanol in TPH,

loaded with Ln (from La to

Gd) 241_Am, 244_Cm, 152_Eu,

139_{Ce traces at 1M HNO} 3

• 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

SF_Ln/Am with [Ln] (strong dependance)

It is not possible to

separate Am from light

Ln if [Ln] > 15 mM

| PAGE 8

MACRO Am EXPERIMENTS

Experimental conditions

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

• Loaded with Ln (up to 20 mM), 241_{Am (up to 2 mM),} 244_{Cm 7} µ_{M (at 1M HNO}

3)

• 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 SF_Cm/Am when [241_Am]

Slight increase of SF_Cm/Am when [TPAEN]

SF_Ln/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 S F (C m /A m ) [TPAEN] (mM) TPAEN P. Kaufholz, Jülich 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 10 20 30 40 S F [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 241_Am, 244_Cm, 152_{Eu and} 139_{Ce tracers}

Aq: 2.5 mmol/L TPAEN in HNO₃at pH_eq=0.7 30 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 Temperature

SF

_Ce/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 HNO3at pHeq~1

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

6 octobre 2015

18 additions of 2 µL [TPAEN] 10 mM in [Eu] 2 mM matrice HNO30.1M

Eu TPAEN baseline dilution reaction

Calorimetry

25 °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 10-3_{M and [TPAEN] = 0 to 1.17 10}-2_{M matrice HNO} 30.1M

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 Eu La Pr Nd Sm 0 1 2 3 4 5 6 7 0.85 0.87 0.89 0.91 0.93 0.95

lo

g

β

1/r (

Å

Å

Å

Å

----1111

))))

Ce Eu La Pr Nd Sm Am Nd (UV) 0 1 2 3 4 5 6 7 0.85 0.87 0.89 0.91 0.93 0.95

lo

g

β

1/r (

Å

Å

Å

Å

----1111

))))

Ce Eu La Pr Nd Sm Am Cm Nd (UV) Eu (SLRT) 0 1 2 3 4 5 6 7 0.85 0.87 0.89 0.91 0.93 0.95

lo

g

β

1/r (

Å

Å

Å

Å

----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 Feed HNO33M HNO₃ FP TODGA 0.2M TPH 5%_vol. octanol Ln Re-Extraction HNO_{3 TPAEN} pH1 Am Ln Am Cm Ln Cm

EXAm Process

Demonstration of the scientific feasibility of the sole Americium separation from a PUREX

raffinate in 1-cyle

Process adapted to a concentrated raffinate (

×

3) in order to reduce contactors size

Objective now = Recovery of Am for (U,Am)O

₂

pellets fabrication

Acknowledgments

E. Russello M.-T. Duchesne V. Vanel V. Pacary M. Miguirditchian S. Chapron X. Hérès F. Burdet M.-J. Bollesteros S. Costenoble M-C. Charbonnel P. Guilbaud …

A. Geist

G. Modolo

A. Wilden

P. Kaufholz

A. Casnati

S. Bourg

Acknowledgments

THANK YOU FOR YOUR

ATTENTION !

| PAGE 14