Research and Development of Advanced Nuclear System

1-9

Toward Engineering Scale Minor Actinides Recovery–Development of Extraction Chromatography Techniques–HLLW*(containing MA)①Eluant

Washingsol.

②③* High Level Liquid Waste
Conc.

NPOO

Extractant(e.g. CMPO (Octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide))

ColumnPacked intoa column
25μm
SiO2-P (SiO2 support coated withstyrene-divinylbenzene polymer)
adsorbents impregnated with CMPO

①’②’

③’

HLLW*MAproductWashingwasteTime①’②’③’
FP** MA FP**(nonadsorbable) (adsorbable)** Fission Products

Fig.1-27 MA recovery by extraction chromatography
SiO2-P adsorbent material impregnated with an extractant is packed into a column. Solution containing MA (①) is fed into thiscolumn, and MA is adsorbed. The adsorbed MA is eluted by a suitable eluant (②), and recovered into a solution (②’). Several
columns with different adsorbents (extractants) may be used for better separation of MA from other elements.
1.6

Sensor inlets

Adsorbents
inlets & outlets

Linear Velocity (mm/s)

1.4
1.2
10.80.6Flowrate:121 cm3/s (downstream)

0.4

Flowrate:121 cm3/s (upstream)

0.2

Flowrate:181 cm3/s (downstream)

0Water jackets

0100

200

Distance from column wall (mm)Fig.1-28 Engineering scale column
Stainless steel column with 48cm inner diameter, which has
water jackets for temperature control and sensor inlets forexperiments.

Fig.1-29 Linear velocity in a column
The uniform flow through a column with 48cm diameter canbe obtained with flow of 121cm3/s (downstream).
About 1.7kg of MA is supported to be recovered in thisflowrate condition.

Studies on minor actinide (MA) recovery by solvent extraction
have been carried out in several countries. These processes use
extractants with diluents, which cause various kinds of liquid
waste in large amounts. In the extraction chromatography
technique, in which extractants are impregnated into support
particles, no diluent is used, and higher MA loading canbe achieved, so this is potentially more economical. We
developed a process and system of MA recovery by extraction
chromatography which can be expanded to an engineering
scale.
We selected a SiO2 support coated with styrenedivinylbenzene polymer (SiO2-P) (Fig.1-27), which has
superior safety and handling properties, and started assessing
SiO2-P adsorbent materials impregnated with several kindsof extractants, e.g. CMPO; adsorption/elution of MA, acidand radiation resistance, and ease of after-treatment of theseadsorbents. These properties are now being measured, andseveral process flows for MA recovery will be designed andevaluated based on these data.
In our development of an engineering scale system, wefabricated an engineering scale column system (Fig.1-28)
and have been investigating the fluidics and thermal control
properties in actual operation, and the durability through longterm operation. Through these investigations, we determined
the operational conditions necessary for uniform flow throughthe column, which is indispensable for steady MA recovery(Fig.1-29).
We also investigated remote control and instrumentation forthe column operation, and we will have overall assessmentsof separation performance, safety, instrumentation and control,
and remote handling based on these results and engineering
scale experiments.
This work was financed by the Ministry of Education,Culture, Sports, Science and Technology of Japan (MEXT)
under the framework of “The Development of Innovative
Nuclear Technologies.”

Reference
Koma, Y., Watanabe, S., Sano, Y. et al., Extraction Chromatography for Am and Cm Recovery in Engineering Scale, Proceedings of 3rd International
ATALANTE Conference (ATALANTE 2008), Montpellier, France, 2008, O1-19, p.8, in CD-ROM.

18

JAEA R&D Review 2008