310 likes | 505 Views
Technical Updates on TRU and TEVA Resins. Anil Thakkar, E. Philip Horwitz, Laurie Wojtko, Lawrence Jassin & Michael Fern November 5, 2001. Topics. TEVA Resin: Extractant (nitrate) vs TEVA Extractant (chloride) TRU Resin: Am Yields TEVA Resin: Decontamination of U-nat/Th in Tc-99 region .
E N D
Technical Updates on TRU and TEVA Resins Anil Thakkar, E. Philip Horwitz, Laurie Wojtko, Lawrence Jassin & Michael Fern November 5, 2001
Topics • TEVA Resin: Extractant (nitrate) vs TEVA Extractant (chloride) • TRU Resin: Am Yields • TEVA Resin: Decontamination of U-nat/Th in Tc-99 region
TEVA Resin: Cl vs NO3 • Uptake of Th, Np and Pu • Preconditioned with 3M HNO3 • Not conditioned • Uptake of Tc-99
TEVA Resin • Nitrate form TEVA- Prepacked columns TE1A • Chloride form TEVA- Bulk lot # TEA0515
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
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
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
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
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
TRU Resin: History • Historical problems with Am recoveries from TRU Resin (HCl strip.) • Suspected Extractant Leaching handled with wet ashing of HCl Strip Solution
TRU Resin Cartridges 1) TRU Resin 2) TRU Resin with a ‘post’ Prefilter layer
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
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
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
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.
Conclusion • Am recoveries improved by changing the concentration on HCl prior to CeF3 • TRU resin cartridge performed well once the HCl concentration was changed
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.
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.
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
Possible Solutions for Decontamination • Use of fluoride to complex the residual Th-234 on the column • Two fluoride solutions tested: • Hydrofluoric acid • Sodium fluoride
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
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