Actinide and Fission Product Partitioning & Transmutation
9th Information Exchange Meeting
Nimes, France, 27 September, 2006

Recent Activities on Aqueous Partitioningat JAEA

Takaumi Kimura, Jun Komaki and Yasuji Morita
Japan Atomic Energy Agency, Japan

Two Types of P&T schemes•Homogeneous recycling with commercialized FR– MA-MOX fuel with aqueous reprocessing– MA-bearing metal fuel with pyrochemical reprocessing•

Double-strata concept with accelerator driven system– MA-bearing nitride fuel with pyrochemical reprocessing

Homogeneous recycling

Double strata concept

Aqueous partitioning technologies
・Advanced aqueous process (NEXT process)- Crystallization of U
- Co-recovery of U-Pu-Np- MA recovery
・4-Group Partitioning Process・Alternative technologies (Innovative extractants & adsorbents)- Selective extraction of U
- Total recovery of TRU- Separation of MA/rare earths- Separation of Sr-Cs
etc.

Overview of the NEXT process•

NEXT (New Extraction System for TRU Recovery) process is excepted
to have some advantages
over the conventional process
based on the PUREX
Disassembling/Disassembling/decladding
decladding– The relative simplicity for remote operation
Dissolution
Dissolution– Volume reduction of organic solvent
Clarification
Clarificationin the extraction process
Crystallization
Crystallization– Reduction in the cost
Co-extraction
Co-extraction
Extraction
for the equipments
Extraction
Co-stripping
Co-stripping
chromatography
chromatography(U,Pu,Npco(U,Pu,Npcoand the hot cell volume
recovery)recovery)– Reducing waste volume
Solvent
Solvent
Am/Cmregeneration
regeneration– Enhancement ofU/Pu/Np
nuclear proliferation High level liquid
Concentration
Concentration
waste
resistance
Adjusting Pu
Pu
AdjustingUcontentcontent

New process technologies
Conventional process technologies

U/TRU (product)

Schematic Flow of the NEXT Process

U (product)Principle of the crystallization
Temp.

T1

Pu, MA, FPU[U]=a1¾Plutonium, MA, FP in dissolver solution• Effect on the purity of UNH crystal(decontamination factor (DF) of theseelements to UNH crystal)

Cooling

T2[U]=a2

UNH crystal¾Recovery of ~70% of U in dissolver solution
as uranyl nitrate hexahydrate (UNH) crystal
by cooling the dissolver solution• Decrease of temp. from T1 to T2→ Decrease of U solubility from a1 to a2

Pu, FPUa2a1
Solute conc.

Solubility curveStudy on the behavior of Pu and FP during
crystallization using U-Pu-HNO3 solution &real dissolver solution is importantPu and FP behavior in the crystallization process•U pre-recovery as UNH crystal by cooling dissolver solution¾ Pu behavior ：Depends on its valence• Pu(VI) : Co-crystallized with U• Pu(IV) : Remained in mother solution¾ FP behavior ：Possibility of crystallization for some FP, e.g. Cs← Required to control the behavior of these elements
Pu ratio in U crystal
Pu(IV), Pu(VI) ratio Crystallization productin solution
Appearance
Pu ratio

Crystallizer

Run1Pu(IV) ： 100%
Pu(VI) ： 0%

100 : 0.3(U) (Pu)

Run2Pu(IV) ： 0%Pu(VI) ： 100%

100 : 5(U) (Pu)

Run3Pu(IV) ： 62%Pu(VI) ： 38%

100 : 1.5(U) (Pu)
Uranium crystal obtained in U-Pu(IV)-CsHNO3 (after washing).

Single Cycle Co-extraction Process for U-Pu-Np Co-recovery

Solvent

Feed
HNO3○Mini centrifugal contactors- Rotor diameter : 30mm
- Rotation speed :Raffinate2,500 – 3,500rpm

LoadedSolvent
Strip

U-Np-Pu co-stripping- Maximum capacity : 5.5 l/h
U-Np-Pu
product- Hold-up :Extraction - Scrubbing

ScrubUsed
Solvent

25ml/stage- 16 stages / bankMini Centrifugal contactors for U-Pu-Np co-recovery

Single Cycle Co-extraction Flowsheet for U-Pu-Np Co-recovery

 U-Pu-Np co-recovery flowsheet trial at CPF

HAraffinate

30% TBP/n-DD

feed

2.3

1*1

234567n-DD
U-Np-Pu
product

80.3

910

11121314

2150.1534567816

HNO3 (50 ºC)

HNO30.04

1HNO3

93.7

10111213141516solvent* flow rate ratio to feed

Results
・DF of Total gamma was about 104.
・Pu and U were not detected in HA raffinate andsolvent(U < 0.03g/L, Pu < 0.2g/L)
・Most of Np was detected in U-Np-Pu product, but alittle Np leaked to HA raffinate (about 2%)

MA recovery (SETFICS: Solvent Extraction for Trivalent f-elements
Intra-group Separation in CMPO-complexant System)
Experimental flowsheet of the SETFICS process using mixersettlers for high loading and application of hydroxylamine nitrate.
Feed*2
Scrub #1
Scrub #2

Solvent*1

Solvent

10 M HNO3

Strip #10.1 M HNO3100 *320300
1 *4790.4 M HAN
pH 2.0Solvent

Strip #2

Strip #30.05 M DTPA–1.5 M HAN
pH 2.20.02 M HNO330
1630

100
1Raffinate

61930160
1Acid waste

5An(III) product*1 0.2 M CMPO–1.4 M TBP in n-dodecane

1980
1Ln waste

16Used solvent*2 Simulated waste solution; 2.6 M HNO3, 0.03 M H2 C2O 4, FP, CP*3 Flow rate, mL/h
*4 Stage number

The loss of Am and Cm obtained in
the counter-current experiment

Decontamination factor obtained in
the counter-current experiment(0.2 M CMPO–1.4 M TBP in n-dodecane)Cs> 3100

Pr> 10Nd
1.8

Sm
1.9

NuclidesAm-241
Cm-242
Cm-244

Loss (%)
0.16
0.39
0.33

MA recovery (Extraction chromatography)○SiO2-P: porous SiO2 covered by SDB polymer○Resin: extactants（CMPO、TODGA、BTP, etc）immobilized in SiO2-P

DV

Feed 3M HNO3HLLW

Cross section of the porous SiO2

EluentWasher3

Zr
Sr(II)
La(III)
Ce(III)

8Nd(III)
lRESr

2pH

The CMPO/SiO2-P resin

Concentration (10-3 mol/dm3)

12dil. HNO3 (pH3.5)

0.05M DTPA - pH2

Sm(III)hRE

Eu(III)
Gd(III)

Pd

Y(III)

4Zr(IV)

1Mo(VI)

Filled in the column

RuRu(III)

Extraction column

Pd(II)

00100

2003004000500

Weight of effluent (g)Separation tests for simulated HLLW by CMPO/SiO2-P resin(Column 10 mmφx 50 mm h, Flow rate 0.76 m/h, Temp. 323K)
WastesMA products

WastesAqueous partitioning technologies
・Advanced Aqueous Process (NEXT process)- Crystallization of U
- Co-recovery of U-Pu-Np- MA recovery
・4-Group Partitioning Process・Alternative technologies (Innovative extractants & adsorbents)- Selective extraction of U
- Total recovery of TRU- Separation of MA/rare earths- Separation of Sr-Cs
etc.

4-Group Partitioning Process
9The 4-Group Partitioning Process wastested with concentrated real HLLW.
Objective elements, Am, Cm, Np, PGM,Sr, Cs, were separated as expected.

High-Level Liquid Waste
Formic acid

Pre-treatment(Denitration)

Precipitate
Pre-treated HLLW
DTPA
~0.5M HNO3
DIDPA
solvent

Solvent
Extraction

Formic acid

Precipitation byDenitration

H2C2O4

SelectiveBack-extraction

TRUTRUGroupGroup
Tc-PGM
Tc-PGMGroupGroup

Rare Earths
Zeolite andTitanic acid

ColumnAdsorption

Sr-Cs
Sr-Cs
GroupGroup

Effluent

OthersOthersGroupGroup

Fig. Flow Sheet of 4-Group Partitioning Process

Am, Cm : >99.998% extracted>99.98% stripped
Pu : >99.99% extracted, >99.98% stripped
Np : 98.2% extracted, >99.93% stripped(>99.95% at optimum condition)
PGM : 99% precipitated
Tc : 96.2% at semi-hot test
Sr, Cs : DF > 104

9No major problem in operation.
9No difference in separation behaviors ofelements between simulated and real
HLLW.
9Process performance, the separated
fraction and secondary wastes wereevaluated.

Development of innovative extractants & adsorbents- Although the main steps of the 4-group partitioning process have been verified,
it is also necessary to improve the partitioning process from viewpoints ofthe economy and the reduction of secondary wastes.

- The R&D effort on the partitioning is presently concentrated on development andimprovement of innovative extractants and adsorbents as alternative technologies.

Selective extraction of U, Total recovery of TRU,
Separation of MA/rare earths and Separation of Sr-Cs.
- Molecular modeling, quantum chemistry, radiation chemistry, structural studies on
extractants and f-element complexes have also been investigated for the R&D of new
extracting molecules.

Selective separation of U (1/2)

C N

We have synthesized several Branched Alkyl
Monoamide (BAMA) to obtain higher selectivity
for U(VI) versus Pu(IV).

OC N

N,N-di-(2-ethyl)hexyl3-methyl-butanamide(D2EHMBA)

SF:DU/DPu = 3.6R1C N

N,N-di-(2-ethyl)hexyl2-methyl-propanamide(D2EHMPA)

79.4

R2Branched Alkyl Monoamide(BAMA)

OO

OR2O

Extraction of U(VI) by BAMA

C N

N,N-di-(2-ethyl)hexyl-2,2-dimethylpropanamide(D2EHDMPA)

182

C N

N,N-di-(2-ethyl)hexyl(2-ethyl)hexanamide(D2EH2EHA)

71.3

Selective separation of U (2/2)
BAMA for selective separation of U(VI)O
C N- D2EHDMPA is one of BAMA which have sterichindrance on the coordination with An ions.

N,N-di(2-ethyl)hexyl-2,2dimethyl-propanamide(D2EHDMPA)- D2EHDMPA can separate U(VI) from Pu, MAand FP without the reduction of Pu(IV).

1.0 M
D2EHDMPA
210

1.5 M D2EHDMPA (3.0 M HNO3)
101

DU(VI)

100Pu(IV)

1. 0.5 M U(VI)・・・・・・

DU = 1.5

2. 50 mM Pu(IV) ・・・・・

DPu = 0.04

3. FP (Sr,Zr,Ru,Rh,Pd,Ba,Nd,Mo,Ce,Tc)
10-1

10-2
10-1・・・・・・
100
HNO3(M)101

4. 0.5 M U(VI)-Tc(VII)・・

DFP ≦0.1
DTc = 0.4

Total recovery of TRU (1/2)
JAEA developed a novel extractant,
N,N,N’,N’-tetraoctyldiglycolamide (TODGA)for the recovery of actinide ions.

4310CH 2NCO CH2CC 8 H17ONOC 8H 17

Structure of TODGAU(VI)
Np(IV)Np(V)
Pu(III)
Pu(IV)
Am(III)
Cm(III)

210C 8 H 17D(An)C 8 H17

0.1M-TODGA + n-dodecane

10110010- High solubility in n-dodecane- Strong extractability for An(III) andAn(IV) from higher HNO3 solution
D(An) > 1000

-110-210-310-210-1

10010

HNO3 conc. / M

110Total recovery of TRU (2/2)
Recent progress4012 mM for Nd(III), 13 mM for Pu(IV)in 0.2 M TODGA/3 M HNO3H2CR1NR2OCO

CH 2CO

R1N
R2

LOC can be improved by modifying
its alkyl groups attached to amidic
nitrogen atoms.
- Back extraction of An(III) and An(IV)by using new water-soluble ligand
TEDGA(N,N,N’,N’-tetraetyldiglycolamide)[Nd3+ ] extracted to org. phase / mM

-The limit of metal concentration (LOC)
35
30
2520
TODGA(n=8)
TDDGA(n=10)
TDdDGA(n=12)

15Aq.：3 M HNO 3Org.：0.1 M DGA/n-dodecane

1050020406080100

Initial [Nd 3+ ] in aq. phase/ mMSeparation of MA/rare earths (1/2)
N-type donor extractant for An(III)/RE(III) separation
Separation in acidic solution and chemical stability were problem.
NO-type hybrid donor extractant for An(III)/RE(III) separation
NO-donor type extractant
Pyridine amidePDAEu

H3C

R2=CH3
R1=Ph
Electronic structure of PDA molecule(calculated by Gaussian98)

N

hard donorCONCONCH3soft donor

Molecular design isrequired to improve
the SF(Am/Lns)

Separation of MA/rare earths (2/2)
Am/Ln separation from 1M-HNO3310PhNMe2Am

Distribution ratio

D(Am) > 1 10NOOPhMeODGA
110Am010PhN
MeNNOPhMeO-110PDAAmSF(Am/Eu) > 10 10-2
at 1M-HNO3PhN
MePhN
MeO-3

1056 58 60 62 64 66 68 70 72
95

Atomic number
Organic phase:
0.1M PDA + ChloroformOMA- Effective and selectiveMA(III) separation fromrare earths using PDA isin progress by modifying
its alkyl groups attached
to amidic nitrogen atoms.

R1R1NR2CONCON
R2e.g., R1=Ph, R2=CH3⇩
R1=Ph, R2=CnH2n+1(n=4, 8, …)

Separation of Sr-Cs (1/2)
Selective adsorbent of Sr-Cs under high nitric acid concentration
Novel inorganic adsorbent (cation exchanger) of Cs- Sodium-silicon-tantalum and sodium-titanium-tantalum mixed oxides- Prepared by hydrothermal synthesis from alkoxides (Si, Ti, Ta)- Highly Cs selective against H+- Stable in nitric acid

Na-Si-Ta-O

Na-Ti-Ta-O- Nature
Si:Ta = 0.7-1.1Amorphous- Kd of Cs from 3 M HNO3
3300 ml g-1 (equilibrium, 4 days)
2320 ml g-1 (24 h)- No decrease of exchange capacity
after leaching by 3M HNO3 at 90 ºC
for 2 days

- Nature
Ti:Ta = 0.26
Crystalline, pyrochlore- Kd of Cs from 3 M HNO3
650 ml g-1 (equilibrium, 2 weeks)
100 ml g-1 (24 h)- No decrease of exchange capacity
after leaching by 3M HNO3 at 90 ºC
for 2 days

Separation of Sr-Cs (2/2)
Novel selective adsorbents (organic-inorganic composite) of Sr or Cs- Inpreganating selective extractants-Crown ether (example 1), for Sr
calix-crown (example 2) for Cs- Porous-silica-based (composite withmacro reticular type polymer) material(SiO2-P) as a non-conventional support

OOO

O

OO

(1) di-t-butylcyclohexano-18-crown-6(DtBuCH18C6)
OO
OOO

O
OO

O
O

(2) 1,3-[(2,4-diethyl-heptylethoxy)oxy]2,4-crown-6-calix[4]arene (calixcrown R14)

SiO2-P support- Studies are undergoing.
- Preparation (selection of extractants /modifiers)- Leaching of extractants into HNO3
- Kd (Sr, Cs, FP, U, TRU)
Note: The studies are performed incooperation with IRI (Institute of Research andInnovation).

Conclusion

JAEA considers that the NEXT process is the most suitable technology
for partitioning of the FR fuel, however, JAEA also proposes alternativetechnologies that are expected to be the options for the NEXT process,considering reduction of the risks for development and future improvementof performance.

ARTIST(Amide-based Radio-resources Treatment with Interim Storage of Transuranics)

Topics:1) Selective separation of U
2) Recovery of TRU by TODGA
3) Sr and Cs separation
4) An/Ln separation

spent fuel
UO2

BAMA processstrage

SrCs
TODGA process

BAMAprocess
PuO2

Sr,Cs separation

FP

N-donor processinterim strage

Np,Pu,Am,
Cm,Ln Oxide(Pu),Np,Am,Cmtransmutation

disposalLn