Demonstration of the TRUEX Process for Partitioning of Actinides from Actual ICPP Tank Waste ...

33 Pages·2005·0.74 MB·English

INEL-96/0353
September 1996
Idaho
National
Engineering
Demonstration of the TRUEX Process
Laboratory
for Partitioning of Actinides from
Actual ICPP Tank Waste Using
Centrifugal Contactors in a Shielded
Cell Facility
J. D. Law
K. N. Brewer
R. S. Herbst
T. A. Todd
OF THIS DOCUMEtiT IS
LOCK H E E D MARTIN^
INEL 96/0353
Demonstration of the TRUEX Process for Partitioning
of Actinides from Actual ICPP Tank Waste Using
Centrifugal Contactors in a Shielded Cell Facility
J. D. Law
K. N. Brewer
R. S. Herbst
T. A. Todd
Published September 1996
Idaho National Engineering Laboratory
Waste Management Technologies
Lockheed Martin Idaho Technologies Company
Idaho Falls, Idaho 83415
Prepared for the
U.S. Department of Energy
Assistant Secretary for
Environmental Management
Under DOE Idaho Operations Office
Contract DE-AC07-94ID13223
DISCLAIMER
Portions of this document may be illegible
in electronic image products. Images are
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document.
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DISCLAIMER
This report was prepared as an account of work sponsored by an agency of the
United States Government. Neither the United States Government nor any agency
thereof, nor any of their employees, makes any warranty, express or implied, or
assumes any legal liability or responsibility for the accuracy, completeness, or use-
fulness of any information, apparatus, product, or process disclosed, or represents
that its use would not infringe privately owned rights. Reference herein to any spe-
cific commercial product, process, or service by trade name, trademark, manufac-
turer, or otherwise does not necessarily constitute or imply its endorsement, recom-
mendation, or favoring by the United States Government or any agency thereof.
The views and opinions of authors expressed herein do not necessarily state or
reflect those of the United States Government or any agency thereof.
ABSTRACT
The TRUEX process is being evaluated at the Idaho Chemical Processing Plant (ICPP) for the
separation of the actinides from acidic radioactive wastes stored at the ICPP. These efforts have
culminated in a recent demonstration of the TRUEX process with actual tank waste. A continuous
countercurrent flowsheet test was successfully completed at the ICPP using waste from tank WM-183.
This demonstration was performed using 24 stages of 2-cm diameter centrifugal contactors installed in
the shielded hot cell at the ICPP Remote Analytical Laboratory. The flowsheet tested consisted of eight
extraction stages, five scrub stages, six strip stages, three solvent wash stages, and two acid rinse stages.
It was determined that a centrifugal contactor stage in the scrub section was not operational during
testing. As a result, the scrub feed (aqueous) solution followed the solvent into the strip section,
effectively eliminating the scrub section in the flowsheet.
An overall removal efficiency of 99.97% was obtained for the actinides. As a result, the activity of
the actinides was reduced from 457 nCi/g in the feed to 0.12 nCi/g in the aqueous raffinate, which is
well below the NRC Class A LLW requirement of 10 nCi/g for non-TRU waste. The 0.04 MHEDPA
strip section back-extracted 99.9998% of the actinide activity from the TRUEX solvent. Removal
efficiencies of >99.90%, 99.96%, 99.98%, >98.89%, 93.3%, and 89% were obtained for 241Am 238Pu,
5
239Pu, 23SU, 238U, and "Tc, respectively. Iron was partially extracted by the TRUEX solvent, resulting in
23% of the Fe exiting in the strip product. Mercury was also extracted by the TRUEX solvent (73%) and
stripped from the solvent in the 0.25 MNa2CO wash section. Only 1.4% of the Hg exited with the high-
3
activity waste strip product.
Data/results of this testing have been independently reviewed by personnel from Argonne National
Laboratory.
in

ACKNOWLEDGEMENTS
The authors would like to acknowledge the EM-50 Tanks Focus Area (TFA) for providing funding
for this demonstration. They would also like to acknowledge C. P. McGinnis and the TFA Technical
Review Group for their support of this program.
The authors would like to thank George Vandegrift, Ralph Leonard, and Monica Regalbuto of
ANL-East for their thorough technical review of the program and experimental results, and for
participating in the demonstration.
Many thanks to E. L. Wade, M. E. Davis, C. W. Lundholm, and G. D. Decoria for their assistance in
installation and operation of the centrifugal contactors and T. G. Garn and R. D. Tillotson for their
assistance with chemical makeup and sample preparations. Also, thanks to T. J. Tranter, D. Thomas, I.
D. Goodwin, and B. J. Storms of the Radiochemical Analysis Group, R. W. Stone of the Spectrochemical
Analysis Group, and the RAL Chemists and Analysts for the efficient, expedient sample analysis results.
Without the work and dedication of these people, this test could not have succeeded.

CONTENTS
ABSTRACT iii
ACKNOWLEDGEMENTS v
INTRODUCTION 1
PURPOSE AND SCOPE 2
EQUIPMENT DESCRIPTION 3
METHODOLOGY/EXPERIMENTAL PROCEDURE 5
WM-183 Waste 5
TRUEX Solvent 6
Analytical 6
TRUEX Flowsheet Demonstration 7
RESULTS AND DISCUSSION 10
TRUEX Flowsheet Demonstration 10
Contactor Operation 10
Time to Reach Steady State ..10
Concentrations at Shutdown 12
Nitric Acid 15
Gross Alpha 15
Americium 15
Plutonium 16
Uranium 16
Technetium 16
Iron 17
Mercury 17
Comparison With Results Obtained Using SBW Simulant 17
CONCLUSIONS AND RECOMMENDATIONS 19
Conclusions 19
Recommendations 19
REFERENCES 20
Appendix A Experimental Data A-l
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TABLES
Table 1. Description of the 2-cm centrifugal contactors 3
Table 2. WM-183 waste and average SBWtank compositions 5
Table 3. Flowrates and O/A ratios for TRUEX flowsheet testing 10
Table 4. Percentage of component in each of the effluent streams for TRUEX flowsheet testing 14
Table 5. Gross alpha, 24IAm, olPu, 239Pu, 23SU, and ™*U distribution coefficients for TRUEX
flowsheet testing 14
Table 6. H+, Fe, and Hg distribution coefficients for TRUEX flowsheet testing 15
Table 7. Composition of simulated SBW 18
Table 8. Comparison of results obtained with simulant and actual waste 18
FIGURES
Figure 1. 2-cm diameter centrifugal contactors installed in the RAL shielded cell 4
Figure 2. Flowsheet for TRUEX demonstration 8
Figure 3. Aqueous raffinate approach to steady state 11
Figure 4. Strip product approach to steady state 11
Figure 5. Actinide approach to steady state, strip product 12
Figure 6. TRUEX flowsheet test concentrations at shutdown 13
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