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New Applications of Rapid Column Extraction for Methods at SRS Sherrod L. Maxwell III Savannah River Site.

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Presentation on theme: "New Applications of Rapid Column Extraction for Methods at SRS Sherrod L. Maxwell III Savannah River Site."— Presentation transcript:

1 New Applications of Rapid Column Extraction for Methods at SRS Sherrod L. Maxwell III Savannah River Site

2 Recent Developments/Applications Current Actinide Methods –Pu/Np/U/Am Sequential methods using TEVA/UTEVA/TRU Resin in F Area Process Lab (alpha, TIMS, ICP-MS) –Sequential Pu/Am/ Sr using TRU/SR Resin in Bioassay Lab New Applications –Sequential column extraction in Bioassay Lab to replace anion resin methods for Pu,Np and U plus enhanced Sr method using cartridge technology –UTEVA for Pu/U removal for Pu/U oxides (Impurity assay) –Actinides in soil using Diphonix Resin-microwave digestion

3 Bioassay Application Current methods –Pu-acidified 500 mL samples/evaporated -AG-1 anion resin –U-acidified 50 mL samples/evaporated -AG-1 anion resin –Pu/Am/Sr- 500 mL calcium phosphate/ TRU + SR Resin Need more efficient, consistent, sequential methods; larger aliquots for special samples

4 Bioassay Application Sherrod L. Maxwell, David J. Fauth, Gerald D. Levi New Methods –Expand use of calcium phosphate precipitation (500 ml to mL) –Enhance vacuum column extraction with cartridge work –Pu (Np when Pu-236 tracer used) on TEVA –U on UTEVA –Pu, (Np)/U using TEVA/UTEVA cartridge technology –Pu, (Np)/Sr using TEVA/Sr cartridge technology

5 Bioassay Application Advantages –Faster, more consistency, less acid waste; reduced labor costs; facilitates sequential analysis; better alpha peak resolution –Better detection limit for uranium-500 mL+ sample (vs. current 50 mL sample size) –Cartridge technology more efficient; eliminates large sequential load solutions (evaporation steps)

6 Challenges Optimize nitrate levels for Pu, Np on TEVA and U, Sr UTEVA/SR Resin work using cartridges Achieve adequate Th-228 removal for Pu/U work Interface with current electroplating practices (Phase II, go to cerium fluoride precipitation)

7 Bioassay Implementation Status Final testing near completion Implementation over next 3 to 4 months Pu-TEVA Pu, Np -TEVA Pu, (Np)-Sr -TEVA/SR Resin Pu, (Np)-U -TEVA/UTEVA

8 Sample Preparation Tracer addition (Pu-242 or Pu-236, U-232) Routine calcium phosphate precipitation –3 mmol Ca (120 mg )+ 15 mmol (NH 4 ) 2 HPO 4 Precipitate/centrifuge/redissolve/ash Redissolve in 6 mL of 6M HNO 3 Add 2.5 M Al(NO 3 ) 3 -scrubbed using UTEVA –7.5 mL for for Pu, Np or Pu, Np/U –5 mL for Pu, Np/Sr Valence adjust Pu and Np: 1; ferrous sulfate 1mL 1.5 M FeSO 4. 2; sodium nitrite (1mL of 3M NaNO 2 )

9 Sample Preparation (contd.) Add 16M HNO 3 as appropriate to increase acidity of load solution –1 mL for Pu, Np/U(adjust acidity to 2.5 to 3.5M) –2 mL for Pu, Np/Sr (adjust acidity to 4.5-5M)

10 Pu, Np/U Using TEVA/UTEVA RESIN

11 Pu-Recoveries Using TEVA/UTEVA Resin 500 mL urine sample/ Pu-242 tracer= 1.25 dpm %Recovery (microprecipitation) % Recovery (Electroplating* ) 1)1101) ) 93.32) )92.63) ) 95.24) ) ) ) 99.36) ) ) ) ) ) ) )106.8 Avg. =102% Avg. = 79% *Add 4 mL 0.02M H2SO4 to enhance F removal during solution cleanup

12 U Recoveries Using TEVA/UTEVA Cartridge 500 mL urine sample / U-232 tracer= dpm % Recovery (Electroplating*) 1) ) ) ) ) ) ) ) ) )106.2 Avg. =81% * Used 0.02MHCl-0.02MHF instead of 0.02M H2SO4 for electroplating

13 Pu/Sr Using TEVA/SR Resin

14 Sr Recoveries using TEVA/Sr Cartridge 500 mL urine sample Sr-90 spiked in samples: 206 dpm Measured dpm % Recovery Avg Sr-90 Spiked after precipitation: Measured:% Recovery % %

15 Pu/U Removal for Impurity Assay Sherrod L. Maxwell, Sheldon. T. Nichols, Vernon Jones, Maureen Schilb Background AG MP-1 Anion Resin for Pu Removal prior to ICP-AES of impurities in metal/oxides to removal spectral interference: –Problem: at least partial retention of Au, Ag, Pt, Ir, Pd, Nb, Tl, La, Ce and Ta on resin –Increased need to analyze mixed Pu/U materials requiring Pu/U removal UTEVA Resin offers improved impurity recovery and removes Pu and U

16 UTEVA Removal of Pu and U UTEVA Resin (diamylamylphosphonate) –Recovers all impurities except Au* –Zr, Ta, Hf, Nb require dilute HF in column load 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

17 UTEVA Pu/U Removal Method Load solution: 10 mL 8 M HNO3-0.04M HF Column Rinse: 14 mL 8M HNO3 (optional with HF) (no HF in rinse to enhance Pu retention; still adequate recovery of Zr, Ta, Hf, Nb; may increase HF with U only to increase Ta, etc., balancing Si background at ICP-torch due to HF) Adjust to 25 mL in graduated tube Pu/U recovery from resin: 20 mL 0.1M HCl-0.05M HF Status: In Use

18 Analysis of CRM-124 Uranium Oxide Standards ElementMeasured Ref. Prepared Value/ %Difference (ppm) dc arc range (ppm) Al102105(81-120)-3% Be (10-17)-7% Cr (50-64)+6% Mg (37-86)+3% Mo (30-50)+7% Na ( )+15% Ni (92-158)+4% V (23-30)-3% W (86-95)+5% Zn (75-115)+8% Zr (67-100)+8% measured = single solution analyzed once by ICP-AES and ICP-MS

19 Actinide Recovery Method for Large Soil Samples Sherrod L. Maxwell and Sheldon. T. Nichols Eliminate sample matrix using Diphonix Resin (load in HCL-HF) Microwave Diphonix Resin to release actinides Apply sequential actinide analysis using TEVA/UTEVA+ TRU Resins, followed by Am-REE on TEVA Resin Successfully applied to 10 gram soil fusions/leaches

20 Summary New implementation of rapid column methods in bioassay lab will result in significant time/cost savings New use for UTEVA resin improves impurity analysis for Pu/U oxides/metals Diphonix resin eliminates matrix problems with large soil samples


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