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Technical Updates on TRU and TEVA Resins
Anil Thakkar, E. Philip Horwitz, Laurie Wojtko, Lawrence Jassin & Michael Fern November 5, 2001
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Topics TEVA Resin: Extractant (nitrate) vs TEVA Extractant (chloride)
TRU Resin: Am Yields TEVA Resin: Decontamination of U-nat/Th in Tc-99 region
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TEVA Resin: Cl vs NO3 Uptake of Th, Np and Pu Uptake of Tc-99
Preconditioned with 3M HNO3 Not conditioned Uptake of Tc-99
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TEVA Resin Nitrate form TEVA- Prepacked columns TE1A
Chloride form TEVA- Bulk lot # TEA0515
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Th & Np procedure (ACW08) 1) Spike 10 ml of 3M HNO3/1M Al(NO3)3 with
Th-229 and Np-237. Add ferrous sulfamate 2) Load solution on TEVA Resin columns 3) Rinse with 35 ml of 2.5M HNO3/0.1 M ferrous sulfamate 4) Rinse with 5 ml of 2.5M HNO3
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ACW08...Continued 5) Strip Th with 20 ml of 9M HCl + 5 mL 6M HCl
6) Strip Np with 10 ml of 0.02M HNO3/0.02M HF
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TEVA Resin: Th-229 recoveries (n=4)
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TEVA Resin: Np-237 recoveries (n=4)
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TEVA Resin: Pu Uptake 1) Spike 10 ml of 3M HNO3 with Pu-242.
2) Load solution on TEVA resin columns 3) Rinse with 10 ml of 3M HNO3 4) Strip with 20 ml of 0.05M HCl / 0.02M TiCl3 / 0.05M HF solution
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TEVA Resin: Pu recoveries
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TEVA Resin Column: Tc-99 1) Precondition columns with 5 mL of 0.01M HNO3 2) Spike 50 mL of 0.01M HNO3 with Tc-99 3) Load on TEVA columns 4) Rinse with 25 mL of 0.01M HNO3 5) Cut column and extrude resin into a LSC vial 6) Add 15 mL of ultima gold cocktail 7) Count on LSC
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TEVA Resin Column: Tc-99 (n=6)
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TEVA Resin: Conclusion
Two forms: chloride and nitrate performed well for Th, Np, Pu & Tc uptake Preconditioning versus not preconditioning doesn’t seem to affect the uptake of Th, Np or Pu Tc-99 recoveries for chloride form are little higher than the nitrate form
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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 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 (n=4)
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RETEST: Am-243 recoveries (n=4)
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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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ACW03…continued 6) Evaporate Am fraction to dryness
7) Add 0.5 ml of conc. HCl and dilute to 15 DI water 8) Perform CeF3 ppt.
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Tap Water: Am-243 recoveries (n=5)
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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
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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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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.
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BWXT’s Procedure tested at Eichrom
Spiked 20 ml of 0.01HNO3 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 0.1 HNO3 Extrude resin in LSC vial Added 15 ml of cocktail and count
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BWXT’s ProcedureTest Results
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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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