Technical Updates on UTEVA, TEVA and TRU Resins

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Technical Updates on UTEVA, TEVA and TRU Resins
Anil Thakkar Michael Fern Eichrom Technologies,
Inc. Paris May 14, 2002
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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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U-232 Yields

• Unrealistic high U-232 yields reported with UTEVA
  resin in samples with high in Pb-210

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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

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Effect of Ferrous210Pb/210Po spike (1100 pCi)
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Effect of Additional 3M HNO3 Rinse 210Pb/210Po
spike
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(No Transcript)
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Effect of Uranium Strip Solution no ferrous
added 210Pb/210Po spike (1100 pCi)
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Additional Rinse/1M HCl Strip Combo
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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

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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

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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.

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BWXTs 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.

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BWXTs 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

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Possible Solutions for Decontamination

• Use of fluoride to complex the residual Th-234 on
  the column
• Two fluoride solutions tested
• Hydrofluoric acid
• Sodium fluoride

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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
• Rinse with 5 ml of 0.1M HNO3
• Extrude resin in LSC vial
• Added 15 ml of cocktail and count

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BWXTs ProcedureTest ResultsRinse volume
used25 mL
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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

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TRU Resin History

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

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TRU Resin Cartridges
1) TRU Resin 2) TRU Resin with a post
Prefilter layer
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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
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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

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Am-243 recoveries (n4)
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RETEST Am-243 recoveries (n4)
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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

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ACW03continued
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.
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Tap Water Am-243 recoveries(n5)
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Conclusion

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