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Technical Updates on UTEVA, TEVA and TRU Resins

Technical Updates on UTEVA, TEVA and TRU Resins. Anil Thakkar & Michael Fern Eichrom Technologies, Inc. Paris May 14, 2002. Topics. UTEVA Resin: Decontamination of Po-210 U-232 yields TEVA Resin: Decontamination of U-nat/Th in Tc-99 region TRU Resin: Am recoveries.

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Technical Updates on UTEVA, TEVA and TRU Resins

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

  2. Topics • UTEVA 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 Ferrous210Pb/210Po spike (1100 pCi)

  6. Effect of Additional 3M HNO3 Rinse210Pb/210Po spike

  7. Effect of Uranium Strip Solution no ferrous added210Pb/210Po spike (1100 pCi)

  8. Additional Rinse/1M HCl Strip Combo

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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

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

  15. 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 HNO3OR with 25 ml of 1M NaF/0.02 HNO3 • Rinse with 5 ml of 0.1M HNO3 • Extrude resin in LSC vial • Added 15 ml of cocktail and count

  16. BWXT’s ProcedureTest ResultsRinse volume used=25 mL

  17. 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

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

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

  20. 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

  21. 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

  22. Am-243 recoveries (n=4)

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

  24. 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

  25. 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.

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

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

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