1. Technical Updates on UTEVA, TEVA and TRU Resins
Anil Thakkar & Michael Fern
Eichrom Technologies, Inc.
Paris
May 14, 2002

2. Topics UTEVA Resin: TEVA Resin: TRU Resin: Decontamination of Po-210
U-232 yields
TEVA Resin:
Decontamination of U-nat/Th in Tc-99 region
TRU Resin:
Am recoveries

3. U-232 Yields
Unrealistic high U-232 yields reported with UTEVA resin in samples with high in Pb-210

4. Current Procedure
1) Load sample on UTEVA resin with 10 ml of 3M HNO3/1M Al(NO3)3. with 2 mL of 0.6M Ferrous sulfamate and 200 mg of ascorbic acid.
2) Rinse sample beaker with 5 mL of 3M HNO3
3) Rinse column with 5 mL of 3M HNO3
4) Rinse column with 5 mL of 9M HCl
5) Rinse column with 20 mL of 5M HCl/0.05M Oxalic
6) Elute U with 15 mL of 0.01M HCl

5. Effect of Ferrous 210Pb/210Po spike (1100 pCi)

6. Effect of Additional 3M HNO3 Rinse 210Pb/210Po spike

8. Effect of Uranium Strip Solution no ferrous added 210Pb/210Po spike (1100 pCi)

9. Additional Rinse/1M HCl Strip Combo

10. Revised Procedure
1) Load sample on UTEVA with 10 ml of 3M HNO3/1M Al(N03)3 with 2 mL of 0.6M Ferrous sulfamate and 200 mg of ascorbic acid
2) Rinse sample beaker with 5 mL of 3M HNO3
3) Rinse column with 5 mL of 3M HNO3
4) Rinse column with 10 mL of 3M HNO3 (3x)
5) Rinse column with 5 mL of 9M HCl
6) Rinse column with 20 mL of 5M HCl/0.05M Oxalic
7) Elute U with 15 mL of 1M HCl

11. Summary
A good decontamination of Po-210 in U-232 region can be achieved by additional 3M HNO3 rinse on UTEVA and eluting uranium selectively with 1M HCl

12. TEVA Column: Tc-99 Issues
Problem reported by Darrin Mann (BWXT, Oak Ridge, Tn) with bias high Tc-99 recoveries in samples with natural uranium.
Th-234 interference was detected in Tc-99 region.

13. BWXT’s Tc-99 Procedure
Solid samples are digested and dissolved finally in 20 ml of 0.1M HNO3
Load sample on TEVA column
Rinse column with 25 ml of 0.1M HNO3
Extrude resin from the column in a LSC vial.
Add cocktail and count on LSC.

14. BWXT’s Procedure tested at Eichrom
Spiked 20 ml of 0.01M HNO3 with ~2000 dpm of U-234/238
Load on TEVA Resin column
Rinse with 25 ml of 0.1M HNO3
Extrude resin in LSC vial
Added 15 ml of cocktail and count

15. Possible Solutions for Decontamination
Use of fluoride to complex the residual Th-234 on the column
Two fluoride solutions tested:
Hydrofluoric acid
Sodium fluoride

16. Decontamination of Th-234
Spiked 20 ml of 0.01HNO3 with ~2000 dpm of U-234/238
Load on TEVA Resin column
Rinse with 5 ml of 0.1M HNO3
Rinse with 25 ml of 0.5M HF/0.02M HNO3 OR with 25 ml of 1M NaF/0.02 HNO3
Extrude resin in LSC vial
Added 15 ml of cocktail and count

17. BWXT’s ProcedureTest Results Rinse volume used=25 mL

18. Conclusion
Decontamination of Th-234 in Tc-99 region can be accomplished with additional fluoride rinse on the TEVA Resin columns
Fluoride in the form of 1M NaF or 0.5M HF solutions could be used to remove the residual amounts of Th-234

19. TRU Resin: History
Historical problems with Am recoveries from TRU Resin (HCl strip.)
Suspected Extractant Leaching handled with wet ashing of HCl Strip Solution

20. TRU Resin Cartridges 1) TRU Resin
2) TRU Resin with a ‘post’ Prefilter layer

21. Am-243 Spike Test 1) Spike 10 ml of 3M HNO3 with 6.52 dpm of Am-243
2) Load solution on TRU cartridges (assisted with VBS, flow rate 1ml/min)
3) Rinse with 10 ml of 3M HNO3
4) Rinse with 5ml of 0.5M HNO3
5) Strip Am with 9M + 4M HCl

22. Cerium Fluoride Precipitation
Four different preparation prior to CeF3 ppt.
1) Digested with Aqua-regia
2) Undigested
3) Changed molarity (~0.5 M HCl)
4) Digested with 10% H2SO4

23. Am-243 recoveries (n=4)

24. RETEST: Am-243 recoveries (n=4)

25. ACW03 tested for Am 0.5 L of Eichrom tap water spiked with Am-243
Precipitated Am with calcium phosphate
Scavenge ppt. and dissolve in the load solution
Followed ACW03 procedure using UTEVA/TRU cartridges
Collect Am fraction

26. ACW03…continued 6) Evaporate Am fraction to dryness
7) Add 0.5 ml of conc. HCl and dilute to 15 ml of DI water
8) Perform CeF3 ppt.

27. Tap Water: Am-243 recoveries (n=5)

28. Conclusion
Am recoveries improved by changing the concentration on HCl prior to CeF3
TRU resin cartridge performed well once the HCl concentration was changed