Streamlining Gallium and Atom Percent Fission Analysis in MOX Fuels with Eichrom Resins

1. Using Eichrom Resins to Simplify the Analyses for Gallium Content and Atom Percent Fission of Irradiated MOX Fuels J. M. Giaquinto D. L. Denton Oak Ridge National Laboratory* Chemical Sciences Division Oak Ridge, Tennessee 37831-6043 *Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract DE-AC05-00OR22725.

2. Presentation Overview • Fissile Materials Disposition Program • Mixed Oxide Fuel Assembly • Separations for Gallium Analysis • Separations for Atom Percent Fission • Some Burnup Results vs. Predicted • Conclusions

3. Fissile Materials Disposition Program (FMDP) • International effort to reduce highly enriched uranium and weapons-grade plutonium stockpiles. • Sep93: Pres. Clinton commits U.S. to eliminate or reduce stockpiles. • Dec96: DOE announces preferred approach for disposal of plutonium will be LWRs. • Dec01: Pres. Bush endorses moving forward with a surplus weapons plutonium program based on using LWRs. ORNL is the lead laboratory for the reactor based initiative. • Mar05: NRC issues licensing amendments for Duke Power to allow the receipt and use of four MOX fuel lead assemblies.

4. Why Gallium? • Commercial light water reactors use a zirconium alloy for the fuel clad material. • Gallium will attack zirconium metal. • Weapons-grade plutonium contains gallium. • Will gallium migrate from the fuel into the clad material and cause degradation?

5. Why Atom Percent Fission Analysis? • Precise documentation of irradiation period for the various tests (PIEs, gallium, fission gas release, etc.) • Validation of INEL computer codes (Gray Chang)

6. MOX Pellets • Fabricated at LANL • ~95% uranium (~99% U-238) • ~5% plutonium (~94% Pu-239)

7. Test Assembly • Stainless Steel outer cladding • Zircaloy inner cladding • 15 MOX pellets • Irradiated in the Advanced Test Reactor (INEL)

8. Un-irradiated MOX Solution Scan

9. Un-irradiated Clad Solution Scan

10. MOX Fuel Fission Products Scan

12. TRU Resin Separation -Conditioned with 4 M HNO3. -Loaded matrix exchanged aliquot onto column. - Rinsed with 4 M HNO3. - Rinse collected with earlier eluant.

14. Sr/TRU Resin Separation • Condition with 6M HNO3 (20mL) • Load matrix exchanged aliquots onto columns • Rinse with 6M HNO3 (7-8mL)

15. Irradiated MOX Post Sr/TRU Separation

16. Irradiated Clad Post Sr/TRU Separation

17. Poor Ba and FP Removal in Clads • ~6,000 ug Zr in load solution • HF complexed with boric acid and matrix exchange into nitric acid • Manageable interferences • High Sn in solution has caused flow problems with some samples

18. ASTM E321 96 Overview • U, Pu, and the Nd fission products are chemically separated and determined by IDMS • Atom fractions are calculated for the dominate contributors and fission product 148Nd • The atom fraction of fuel consumed is equal to the atom fraction of 148Nd/148Nd effective yield • Percent burnup is calculated by dividing the atom fraction of fuel consumed by the unirradiated sum of the dominate fissionable isotopes

19. High Mass Fission Products Natural Nd check mass Spike mass Burnup mass

20. ASTM E321 96 Nd Separations

21. Eichrom Technologies Ln Resin • di(2-ethylhexyl) orthophosphoric acid (HDEHP) • Hydrophobic support • Resin capacity: 2-4 mg Nd/mL Ln resin

22. Ln Resin Simplified Separation • 5 mL to 6 mL bed volume • Resin conditioned with 0.18 M HCl • Sample matrix adjusted to 0.18 M HCl • Sample loaded onto column and rinsed through with 0.18 M HCl. Eluant collected in 5 mL fractions. • Nd fractions combined for MS analysis

25. Conclusions • Combining Eichrom Sr and TRU Resins provide for a simple and effective solution for Ga analysis by ICPMS • Eichrom Ln resin provides for an effective baseline separation of the high mass fission products (REEs) • Data supports FMDP goals for reducing Pu stockpiles by using MOX fuels in commercial LWRs. • Security and waste issues still remain however.