On-line Actinide Quantification with Extractive Scintillating Resins

1. On-line Actinide Quantification with Extractive Scintillating Resins Timothy A. DeVol, James E. Roane, Lara D. Hughes Clemson University Eichrom Users’ Group Workshop May 4, 2004

2. Need for Monitoring Method • Radionuclide contamination in natural waters • natural • anthropogenic • Radionuclide specific and gross alpha analyses • primarily laboratory based • can be time intensive and costly • Need for in-situ and on-line monitoring • site assessment before, during and following remedial action

3. Sample Concentration Sample Data Detection Prep Separation Sample Concentration Sample Data Separation Prep Detection Dual FunctionalitySimultaneous Concentration and Detection Li and Schlenoff, 1994 DeVol, et al., 1997 Campi, et al., 1998 Link and Synovec, 1999 Egorov, et al., 1999 Headrick, et al., 2000 Heimbuch, et al., 1964

4. Inert polystyrene chromatographic supports (100 - 150 mm particle size, ~700 m2/g) Extractive Scintillating Resin

5. Experimental- Flow cell procedure • Flow cell • resin dry packed into FEP Teflon tubing • placed in front of PMT(s) • Test procedure • conditioning, loading and washing steps with appropriate reagents • collecting on-line data during flow • pulse height spectra before and after load • aliquots of effluent analyzed off-line (mass balance) • Radioactivity • spiked solutions of 241Am, 239Pu and 233U • Anthropogenic samples • natural groundwater containing U

6. Simultaneous Separation and Detection Manually controlled pump Extractive Scintillator in Flow-cell Radiation Detector Effluent Loading Solution LSC Sample Eluant Computer

7. Flow-Cell Detection Systems Ultraviolet Illumination Coincidence System for TRU ES Modified Hidex Triathler for Actinide ES Modified Eberline E-600 for Tc ES II

8. TRU ES Loading Profile I Condition w/ 2 M HNO3 II Load 239Pu in 2 M HNO3 III Rinse w/ 2 M HNO3 I II III

9. TRU ES Pulse Height Spectra 239Pu Background

10. Chromatographic capacity of the ES TRU resin as illustrated by the loading and elution of 233U k’ ~ 3000

11. Sequential Elution of 241Am, 239Pu and 233U from TRU ES Resin On-Line Counting Off-Line Counting

12. Analysis of SRTC High Level Waste Sludge Plot of average activity (n=3) with 1 standard deviation

13. On-Line Monitoring233U in Synthetic Groundwater 8.62 Bq L-1 CR(cps) = 0.165 + 4.631*V(L) R= 0.99 4.92 Bq L-1 CR(cps) = 0.159 + 2.729*V(L) R= 0.97 1.74 Bq L-1 CR(cps) = 0.151 + 0.650*V(L) R= 0.95

14. Monitoring Natural Uranium in Water 125 mL sample acidified to 0.5 M HCl Expected 7.48 Bq/L Measured 9.6 Bq/L from slope of first 50 mL

15. Actinide ES Resin 685 mg U/L 17.4 Bq/L

16. m 30 mg uranium/L (0.76 Bq/L) Actinide ES Resin Natural Uranium in Groundwater acidified to pH 1

17. Summary of Results

18. Conclusions • Extractive scintillating resins are selective dual-purpose media • High ea • Transparent to scintillation light • Chromatographic property of ES resin is similar to non-scintillating commercially available resin • Quantification has been demonstrated on-line • Applicable toward environmental screening applications. Continuing to work on solving the stability, sensitivity, benign sample matrix, and reusability issues

19. FUTURE WORK • Solve the problems that affect the results, such as, • Chemical luminescence • Dark adaptation time • Signal variation with radionuclide position in flow-cell • Optimize flow-cell geometry for maximum sensitivity • Develop ruggedize field instrument and demonstrate in the field • Off-line evaluation procedures

20. Acknowledgments Dr. James Harvey, Dr. Jonathon Duffey, and Joel Williamson at Eichrom Technologies, Inc. NSF SBIR Phase I contract # NSF/SBIR-9760934 DOE Office of Science (BER) grant DE-FG07-99ER62888