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Recent Improvements in Rapid Column Separation Methods at SRS

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 Improvements. SRS Environmental Monitoring lab faster water and air filter analysis for actinides

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Recent Improvements in Rapid Column Separation Methods at SRS

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  1. 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

  2. Recent Improvements • SRS Environmental Monitoring lab • faster water and air filter analysis for actinides • improved soil-fecal sludge analyses (wastewater treatment plant samples) • SRS Bioassay lab • improved Pu-Np column extraction for urine (better Pu stripping/less volume) • faster fecal analysis method (no microwave) • Central Laboratory (process lab) • improved Pu, Np in HEU and LEU samples • TEVA + Pu-236 tracer

  3. SRS Environmental Monitoring Lab • Vacuum box systems and stacked cartridges • Significant cost and time savings vs. gravity flow • Tested both stacked UTEVA+ TRU and TEVA+TRU methods • both methods work very well; much faster than gravity flow • eliminated evaporation of Am fraction: use 5 mL con HF • use 50 ug cerium instead of 100 ug to improve peak resolution

  4. SRS Environmental Monitoring Lab • Showed stacked TEVA+TRU can be used on water samples • just like urine method- no iron interference • may have some advantages for air filters (Po-210 interference) • Po-210 can interfere with U-232 on UTEVA • allows Pu AND Np together on TEVA • use Ti (III) reductant in Pu strip from TEVA when performing cerium fluoride microprecipitation

  5. Pu, Np/Am, U, Sr on TEVA/TRU RESIN (Water/Air filters) 1) Redissolve in 10 mL 3M HN03 - 0.5M Al(NO3)3 2) Add 0.5 mL 1.5M Sulfamic Acid + 1 mL 1.5M Ascorbic Acid 3) Add 1 mL 3.5M Sodium Nitrite Th Removal 3mL 9M HCI/25mL 8MHCI Rinse 20 mL 3M HN03 Pu Elution 20mL 0.10M HCl - 0.05MHF - 0.03M TiCl3 Add 0.5 mL 3M sodium nitrite 2mL TEVA Resin (50-100 um) Cerium fluoride Alpha spectrometry Remove TRU cartridge: 1) Elute Am with 15mL 4M HCI 2) Elute U with 10mL 0.1M ammonium bioxalate 2.0mL TRU-Resin (50-100 um) Collect, evaporate, dissolve in 6M HNO3 Sr Resin

  6. Pu-242 Tracer Recoveries 1000 mL water samples/ Pu-242 tracer= 4.40 dpm Calcium phosphate precipitation % Pu242 Recovery % Pu242 Recovery UTEVA+TRU Method TEVA+TRU Method 1) 101 1) 99.3 2) 106 2) 105 3) 106 3) 105 4) 108 4) 109 5) 98.6 6) 102 Avg. = 105% (2.8% @1s) Avg. = 103% ( 3.8% @1s)

  7. Am-243 Tracer Recoveries 1000 mL water samples/ Am-243 tracer= 3.84 dpm Calcium phosphate precipitation % Am-243 Recovery % Am-243 Recovery UTEVA+TRU Method TEVA+TRU Method 1) 105 1) 98.4 2) 100 2) 99.0 3) 91.5 3) 107 4) 98.7 4) 100 5) 102 5) 106 6) 106 6) 105 Avg. = 101% (5.2% @1s) Avg. = 103% ( 3.8% @1s)

  8. U-232 Tracer Recoveries 1000 mL water samples/ U-232 tracer= 5.45 dpm Calcium phosphate precipitation % U-232 Recovery % U-232 Recovery UTEVA+TRU Method TEVA+TRU Method 1) 92.9 1) 87.5 2) 98.2 2) 93.5 3) 96.2 3) 97.4 4) 94.9 4) 92.4 5) 91.6 5) 94.0 6) 93.2 Avg. = 94.5% (2.6% @1s) Avg. = 93.0% ( 3.8 % @1s)

  9. SRS Environmental Monitoring Lab • Actinides in soil-fecal samples • dissolution and column flow problems with current method • need total dissolution/eliminate flow problems & low uranium • use Diphonix resin technology as in bioassay lab • Initial testing encouraging • Use sodium peroxide/sodium hydroxide fusion (Zr crucibles) • Precipitate actinides as hydroxides; redissolve in HCL-HF/also boric acid fraction • 4 mLs Diphonix Resin + small volume HEDPA strip (15-20 mLs) • Faster HEDPA destruction method (no microwave) • modified Fenton’s Reagent method • Routine size Eichrom columns

  10. Diphonix Stripping-HEDPA 0.5M HEDPA % Pu242 % U232 Strip Volume Tracer Tracer 1) 3 mL resin 15 mL 104 96 2) 4 mL resin 15 mL 99 97 3) 4 mL resin 20 mL 105 84 4) Direct -HEDPA 20 mL 113 113 Avg= 105 % 98 % Redissolve in 10 mLs 6M HNO3 and 10 mls 2.5M aluminum nitrate (to avoid phosphate interference), then TEVA+ TRU Column extraction

  11. Soil-Fecal Sludge Samples Pu-242 Pu-238 Pu-239/240 % Recovery pCi/g pCi/g 1) 101% 0.435 2.18 2) 69 % 0.484 2.33 3) 84% 0.442 2.07 4) 49 %0.4482.39 Avg= 76% 0.452 (4.8% @1s) 2.24 (6.5% @1s)

  12. Soil-Fecal Sludge Samples U-232 U-234 U-235 U-238 % Recovery pCi/g pCi/g pCi/g 1) 56% 6.16 0.355 5.56 2) 75 % 5.44 0.351 4.76 3) 74% 5.28 0.346 5.04 4) 98 %4.440.2533.98 Avg= 76% 5.33 (13% @1s) 0.326 (15% @1s) 4.84 (14% @1s)

  13. Soil-Fecal Sludge Samples Am-243 Am-241 Cm-244 % Recovery pCi/g pCi/g 1) 73% 0.746 0.506 2) 53 % 0.684 0.506 3) 64% 0.620 0.462 4) 38 % 0.6700.378 Avg=57% 0.679 (7.6% @1s) 0.464 (13% @1s)

  14. Bioassay Lab Improvements • Actinides and Sr-90 in urine • stacked TEVA+TRU Resin cartridges with vacuum boxes • Pu-236 tracer for Pu and Np at same time • Pu, Np (TEVA) and U, Am (TRU) • Sr (Sr Resin) • Pu stripping improvement: • improved Pu stripping with rongalite instead of iodide in strip solution (less volume/faster flow rate) • rongalite (sodium formaldehyde sulfoxylate) • compatible with electroplating • adjust bisulfate added for sulfate added from rongalite decomposition (2.5 mLs 10 % bisulfate instead of 3 mLs)

  15. Urine Batch: Calcium Phosphate Precipitation

  16. Pu, Np/Am, U, Sr on TEVA/TRU RESIN (URINE) 1) Redissolve in 12 mLs of 3M HN03 - 1M Al(NO3)3 2) Add 0.5 mL 1.5M Sulfamic Acid + 2 mls 1.5M Ascorbic Acid 3) Add 2 mLs 4M Sodium Nitrite Th Removal 5mL 9M HCI/ 25mL 8M HCI Rinse 20 mL 3MHN03 Pu Elution 20mL 0.10M HCl - 0.05M HF - 0.015M Rongalite 4mls 0.02M H2SO4 + 3mls 16M HN03 2mL TEVA Resin (50-100 um) Evaporate/ash Electrodeposition Remove TRU cartridge: 1) Elute Am with 15mL 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

  17. TEVA+ TRU Stacked Column: Pu, Np, U, Am

  18. TRU Cartridge: U, Am Stripping

  19. SR Cartridge: Sr-90 Separation

  20. Pu-236 Recoveries-UrineUsing TEVA/Rongalite Pu-236=0.426 dpm 500 mL urine Avg Recovery=99%

  21. Spiked Urine Samples: Rongalite Test Known values: Avg. measured: Pu-238 =0.110 dpm/L Pu-238 =0.143 dpm/L Pu-239 =0.857 dpm/L Pu-239 =0.848 dpm/L Np-237=0.535 dpm/L Np-237=0.508 dpm/L

  22. Bioassay Lab Improvements • Bioassay: fecal method • wet ashing and dissolution in HCL-HF • Diphonix Resin • TEVA+TRU Resin • cartridges not stacked due to possible iron • previously evaporated load plus rinse from TEVA then redissolved, added reductant and loaded onto TRU • Pu, Np (TEVA) and U, Am (TRU) • Sr (Sr Resin)

  23. Recent Improvements in Fecal Method • Improvements: • no evaporation of load solution from TEVA to save time • collect load plus minimal rinse from TEVA • add sulfamic acid + ascorbic acid and load to TRU resin • improved Pu stripping with rongalite instead of iodide in strip solution • Also testing: • use of HEDPA strip of Diphonix instead of microwave (minimize HEDPA to minimize phosphate and increase Al in final load solution) • Use sodium peroxide/sodium hydroxide fusion instead of wet ashing

  24. Microwave Digestion of Diphonix: Fecal Method

  25. Testing using 15 mL strip with 0.04M Rongalite; acidify to 3M HNO3, add Al(NO3)3 and nitrite and load to second TEVA column Collect load and small rinse ONLY: Eliminated evaporation 5

  26. Pu on TEVA Resin-Fecal (2nd Column to Remove all Th-228) • Adjust acidity of 15 mL strip solution to 3M HNO3 using 4 mLs 16M HNO3 • Add 1 mL of 2.5M aluminum nitrate • Add 1mL 3.5 M Sodium Nitrite Th Removal 3mL 9MHCI/7mL 8MHCI Rinse 10mL 3MHN03 Pu Elution 20 mL 0.10MHC1 - 0.05MHF - 0.015M rongalite 1mL TEVA Resin

  27. 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

  28. Summary • SRS Environmental Monitoring lab work • Vacuum box technology reduced method time by about 50% • Diphonix-HEDPA may help with difficult soil-fecal samples • Bioassay lab • Improved Pu stripping using rongalite (85% to 99%) • HEDPA to eliminate microwave in fecal analysis • Process lab • Pu-236 tracer use for Pu, Np in process lab on high uranium samples

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