NUCL 132 |
| A key feature of the proposed Department of Energy's (DOE) Global Energy Partnership (GNEP) initiative is to specifically remove various groups of actinides and fission products (Cesium /Strontium) via an aqueous reprocessing scheme that recycles both fissile and fissionable radioisotopes for efficient nuclear energy production. Even though the more traditional-and repository limiting- radioactive isotopes (with both relatively short and long half –lives) are removed via earlier Cs/Sr separation steps or recovered as a useful fissile or fissionable material, there still remains sufficient radio toxicity and some chemical toxicity associated with final separation stage raffinates to justify their long–term immobilization in a deep geological repository. As such, these remaining high-level waste components (Ln and non-Ln fission products) must be immobilized with both high waste loadings and high durability to meet the current constraints of the repository without exceeding the repositories capacity over the next 100 years. To accomplish these objectives this paper explores, investigates, and evaluates the use of synthetic ceramics of specific crystalline assemblages as waste forms for the remaining GNEP high–level waste. Of all the different classes of ceramics, this paper specifically addresses the monazite class along with its research history, mineralogy, properties, and fabrication methods. Since the monazite ceramic waste form is geologically known to incorporate thorium and uranium (and therefore maybe other trace actinide isotopes it is logical to evaluate and study this form since the use of actual waste constituents (e.g., the Lanthanides and Rare Eartg elements) to construct the underlying monazite structure (e.g., Ln ortho phosphates)- may result in exceptional waste loadings with superb durability. |
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Global Nuclear Energy Partnership (GNEP): Science and Technology for a Nuclear Future
1:30 PM-5:10 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 253, Oral
Division of Nuclear Chemistry & Technology |