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Recent Improvements in Rapid Column Separation Methods at SRS. S. L. Maxwell, III, D. J. Fauth, R. C. Henderson, J. J. Smiley, S. R. Johnson Westinghouse Savannah River Site. Recent Column Extraction Applications. Column Extraction Applications at SRS Soil and Fecal Sample Analyses
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Recent Improvements in Rapid Column Separation Methods at SRS S. L. Maxwell, III, D. J. Fauth, R. C. Henderson, J. J. Smiley, S. R. Johnson Westinghouse Savannah River Site
Recent Column Extraction Applications • Column Extraction Applications at SRS • Soil and Fecal Sample Analyses • Actinides in soil using Diphonix Resin-microwave digestion • S.L. Maxwell III and S. Nichols, “Actinide Recovery Method for Large Soil Samples”, Radioactivity and Radiochemistry, 11, No 4, 46, (2000) • Pu, Am in fecal samples using Diphonix Resin-microwave digestion and TEVA+TRU Resin, (1999) • S.L. Maxwell and D. Fauth, “New Fecal Method for Pu and Am”, Journal of Radioanalytical and Nuclear Chemistry, Vol. 250, No. 1 , 2001
Recent Column Extraction Applications • Column Extraction Applications at SRS, contd. • Bioassay: urine • Column extraction in Bioassay Lab for Pu, Np, Am, U plus Sr method using cartridge technology • S.L. Maxwell III and D. Fauth, “Rapid Column Extraction Methods for Urine”, Radioactivity and Radiochemistry, 11, No 3, 28, (2000)
Bioassay Urine Methods • Improve chemical recoveries, improve Th-228 removal and reduce labor costs/rework • Pu (+Np when Pu-236 tracer used) on TEVA Resin • Pu, Np, U, Am, Sr • Single two cartridge TEVA/TRU column plus SR Resin • No iron in urine allows novel, stacked TEVA+TRU column • Pu, Np on TEVA; U, Am on TRU cartridge in stacked column • Sr collected, evaporated, redissolved, separated on SR Resin column
Pu, Np/Am, U, Sr on TEVA/TRU RESIN (URINE) 1) Adjust to 2.5MHN03 - 1M Al(NO3)3 2) 0.05M Sulfamic Acid + 0.2M Ascorbic Acid 3) 0.4 to 0.5M Sodium Nitrite Th Removal 3mL 9MHCI/30mL 8MHCI Rinse 20 mL 3MHN03 Pu Elution 30mL 0.10MHC1 - 0.05MHF - 0.1M NH4l 4mls 0.02M H2SO4 + 3mls 16M HN03 2mL TEVA Resin (50-100 um) Evaporate/ash Electrodeposition Remove TRU cartridge: 1) Elute Am with 12mL 4M HCI 2) Elute U with 20mL 0.1M ammonium bioxalate 2.0mL TRU-Resin (50-100 um) Collect, evaporate, dissolve in 6M HNO3 SR Resin
TEVA Pu Tracer Recoveries 500 mL urine sample/ Pu-242 tracer= 1.25 dpm / One TEVA Column Fe+AA/+NO2 %Recovery (CeF3 microprecipitation) % Recovery (Electroplating* ) 1) 110 1) 84.4 2) 93.3 2) 72.4 3) 92.6 3) 69.3 4) 95.2 4) 69.6 5) 101.5 5) 79.8 6) 99.3 6) 84.5 7) 97.7 7) 79.1 8) 115.4 8) 85.5 9) 107.9 9) 84.8 10) 106.8 10) 77.0 11) 101.6 11) 82.5 12) 102.6 Avg. = 102.0% (7.0% @1s) Avg. = 79.0 (6.2% @1s) *Add 4 mL 0.02M H2SO4 to enhance F removal during solution cleanup for plating
TEVA- Np-237 , Pu-236 Recoveries 500 mL urine sample/ Np-237 spike= 1.40 dpm/Pu-236=0.425 dpm Single TEVA column (CeF3 microprecipitation) % Pu-236 % Np-237 Recovery Recovery 1) 94.0 *** 2) 92.5 *** 3) 101 *** 4) 100 *** 5) 111 *** 6) 91.0 88.1 7) 91.9 86.7 8) 105 102.9 9) 109 102.0 10) 88.994.2 Avg. =98.4% (7.9% @1s) Avg. = 94.8% (7.6% @1s) Additional bias comparison on 24 samples: -1.49% +/- 6% estimate of bias
TRU Resin -Am Tracer Recoveries 500 mL urine sample/ Am-243 tracer= 1.55 dpm / TRU cartridge after TEVA SA+AA/+NO2 / load TEVA and TRU at same time/remove TRU cart./elute Am % Am-243 Recovery (Electroplating) 1) 93.2 2) 92.1 3) 107.4 4) 70.3 5) 102.4 6) 103.0 7) 100.2 8) 103.3 9) 102.6 10) 94.7 Avg. = 96.9% (10.6% @1s)
Pu on TEVA RESIN (2nd Column to Remove all Th-228) • Redissolve in 7.5mL 3M HN03 + 1mL 2.5M Al(NO3)3 • Add 0.5mL 1.5M Ferrous Sulfate + 1mL 1.5M Ascorbic Acid • Add 1mL 3.5M Sodium Nitrite • Add 1mL 16M Nitric Acid Th Removal 3mL 9MHCI/7mL 8MHCI Rinse 10mL 3MHN03 Pu Elution 20 mL 0.10MHC1 - 0.05MHF - 0.1M NH4l 1mL TEVA Resin
UTEVA Pu/U Removal for Metals Assay at Savannah River • UTEVA Resin (diamylamylphosphonate) • Recovers all impurities except Au* • Zr, Ta, Hf, Nb require dilute HF in column load (and/or rinse) solution • Handles Pu, U or Pu/U mixtures • Large 10 mL columns remove 200 mg or more of Pu/U * Au done by dilute HCL-HF cation method
UTEVA Pu/U Removal Method for Impurities Assay • Glove box separation for Pu materials • Load solution: 10 mL 8 M HNO3-0.04M HF • Column rinse: 14-19 mLs 8M HNO3 (optional with HF) • Adjust to 25 or 30 mL in graduated tube • Pu/U recovery from resin: 20 mL 0.1M HCl-0.05M HF
Average Column Spike RecoveriesICP-MS Element % Recovery Element % Recovery Element % Recovery Ag 106 Hf 90Se 87 Al 101 Hg 77Si 132 As 88 K 102 Ta 84 B 89 La 108 V 104 Ba 106 Li 101 W 113 Be 90 Mg 103 Zn 91 Ca NA Mo 101 Zr 63 Cd 94 Na 98 Ce 108 Nb 98 Cr 103 Ni 103 Cu 106 P 154 Fe 106 Pb 99 Ga 101 S NA
Process Lab Improvements • Process samples to support HEU Blenddown processing • Improvements: • Pu and Np are key product specification measurements • Pu-236 tracer for Pu and Np on TEVA resin in HEU and LEU process solutions • 1 mL TEVA cartridges to ensure total Th-228 removal (separated twice on TEVA) • use Ti (III) reductant in Pu strip from TEVA
Summary • New rapid column extraction methods have greatly improved radiochemical separation technology • process lab support • bioassay lab applications • environmental lab work • Vacuum-enhanced column and cartridge extraction methods have enhanced lab capabilities • simpler, faster, less rework, less waste • Rapid extraction technology continues to advance at the frontier of radioanalytical chemistry