Title  Dissolution, Reactor, and Environmental Behavior of ZrO2-MgO Inert Fuel Matrix	Researchers K. Czerwinski Collaborators Mitchell Meyer, Idaho National Laboratory
Background  There has been a recent resurgence of interest in different oxide fuel types (e.g., Th, inert matrix, and Pu fuels) as potential advanced fuels that can be operated to relatively high burnups at lower costs than current UO2 fuels. These fuels can also be formed to incorporate transuranics elements in the matrix.  Inert fuel matrices have the advantage of burning Pu and other transuranic elements from the fuel cycle without the production of other actinide elements.  Of the possible materials for use in an inert matrix, ZrO2 has been examined.  The inclusion of ZrO2 is expected to increase chemical stability and radiation resistance.  The natural analogue of zirconia, baddeleyite ((Zr,M)O2), where M is a tetravalent ion such as hafnium), contains up to 3000 ppm U or Th.  This supports the durability of inert matrix fuels using ZrO2 in reactor conditions and repository conditions.  However, fuels appropriate for the advanced fuel cycle applications should have desirable reprocessing properties, namely ease of dissolution for separations.  An additional oxide which is somewhat soluble may need to be added to the ZrO2 matrix to achieve desirable reprocessing properties.  A candidate oxide is MgO.	Research Objectives and Methods This project will examine inert fuels containing ZrO2 and MgO as the inert matrix.  Ceramics with this inert matrix, Ce, U and eventually Pu will be synthesized and examined.  While the Advanced Fuel Cycle Initiative focus is on inert fuels with Pu as the fissile component, this task will perform initial laboratory experiments with Ce and U.  The initial work with Ce will be performed early in the project with results used as a basis for U studies.  Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf.  Most fuels use Gd or Er, but the chemical properties of Hf lend themselves to formation of solid solutions with Zr and the tetravalent actinides and will therefore be investigated.  This project will provide the necessary data for evaluating the performance, reprocessing, and waste behavior of the MgO-ZrO2 fuels from a quantified, chemical perspective.  Reactor physics calculations are used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10% of 239Pu.  Ceramics are synthesized and characterized based on the reactor physics results.  The solubility of the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, are investigated in a manner to provide thermodynamic data necessary for modeling.  The research objectives of this project are as follows:   · To examine the neutronic behavior of MgO-ZrO2 inert fuels.  Variation of MgO and ZrO2 composition ranges from 30% to 70% MgO in ZrO2.  Analysis of Gd, Er, and Hf for reactivity control ranging from 5-10% lanthanides.  Analysis of reactor grade Pu as fissile component ranging from 5-10% Pu.  Results will be used as parameters for fuel composition. · To synthesize and characterize MgO-ZrO2 ceramics containing burnable poison and fissile composition.  Synthesis is based on a precipitation method.  Range of MgO in ZrO2, fissile component concentration, and burnable poison concentration based on results of neutronic calculations.  Characterization of ceramics will include density, X-ray diffraction (XRD), surface area analysis, X-ray absorption fine structure, and chemical composition.  Results will be applied to behavior in high temperature water, acid, and environmental conditions. · To describe the chemical behavior of synthesized ceramics.  Chemical thermodynamic and kinetic analysis will use equilibrium data, kinetic data, and surface area normalized dissolution.  Different conditions will include reactor conditions (high temperature and high pressure water) and reprocessing conditions (nitric acid and elevated temperature).  Environmental conditions will be near neutral solution conditions. · To utilize project data in kinetic and thermodynamic modeling codes to evaluate the speciation of the elements in the ceramics under reactor, reprocessing, and repository conditions.
Students  Kiel Holliday G	Department Chemistry
Final Report	Annual Report
Proposal 04/01/04	Quarterly Reports   07/01/04-09/30/04  10/01/04-12/31/04   01/01/05-03/31/05  04/01/05-06/30/05   01/01/06-03/31/06
Papers Neutronic Evaluation of MgO-ZrO2 Inert Fuels - July 2006 (final  report) Neutronic Evaluation of MgO-ZrO2 Inert Fuels - Jan. 2006 (3rd Progress  report) Neutronic Evaluation of MgO-ZrO2 Inert Fuels - June 2005 (final  report) Neutronic Evaluation of MgO-ZrO2 Inert Fuels - Oct. 2004 (progress report) Neutronic Evaluation of MgO-ZrO2 Inert Fuels - July-Sept. 2004 (progress report benchmark) Dissolution, Reactor, and Environmental Behavior of ZrO2-MgO Inert Fuel Matrix - Feb. 2005 (progress report) Dissolution, Reactor, and Environmental Behavior of ZrO2-MgO Inert Fuel Matrix - May 2005 (final progress report) Revisiting Basics of Fertile-Free-Fuel Reactor Physics - Dec. 2004 (abstract) The Effect of Ln(III) / An(III) Separation on Feasibility of TRU Recycling in PWRs - IYNC 2006 (draft) Monthly Report Jan. 2006	Researchers E. Fridman, A. Galperin, E. Shwageraus E. Fridman, A. Galperin, E. Shwageraus E. Fridman, A. Galperin, E. Shwageraus E. Fridman, A. Galperin, E. Shwageraus , S. Kolesnikov E. Fridman, A. Galperin, E. Shwageraus , S. Kolesnikov E. Fridman, A. Galperin, E. Shwageraus , S. Kolesnikov E. Fridman, A. Galperin, E. Shwageraus , S. Kolesnikov E. Fridman, E. Shwageraus

 Thesis
M.S. Mechanical Engineering, Satish Dronavalli, “Residual Stress Measurements and Analysis by Destructive and Non Destructive Techniques” Aug. 2004 (TRP Task 14)
M.S. Mechanical Engineering, Anand Venkatesh, “Comparative Analyses of Residual Stresses in Target Sub-System Materials” Aug. 2004 (TRP Task 14)
M.S. Mechanical Engineering, Vikram Marthandam, “Metallurgical Characterization and Residual Stress Measurements of Target Structural Materials” Aug. 2004 (TRP Task 14)