Document Type

Grant

Publication Date

5-31-2003

First page number:

1

Last page number:

2

Abstract

Fluorapatite, fluorinated calcium phosphate, has been identified as a potential matrix for the entombment of the zirconium fluoride fission product waste stream from the proposed FLEX process. If the efficacy of fluorapatite-based waste-storage can be demonstrated, then new and potentially more-efficient options for handling and separating high-level wastes, based on fluoride-salt extraction, will become feasible. This proposal will develop a dual-path research project to develop a process to fabricate a synthetic fluorapatite waste form for the ZrF4, FP waste stream, characterize the waste form, examine its performance under environmental conditions, and correlate the behavior of the waste form with natural analogs. Characterization of the material will be accomplished through probing the molecular-scale electronic and geometric structure of the materials in order to relate them to macroscopic properties, with the goal of developing techniques to evaluate and predict the performance of different waste-form materials. Time and funding permitting, other waste forms for the zirconium fluoride, fission product salt waste stream will be examined and benchmarked against the fluorapatite matrix baseline.

Highlights of Accomplishments:

1. Baseline spectroscopic measurements have been obtained for commercial hydroxyapatite and natural fluorapatite using a wide variety of techniques (e.g., Raman, XPS, FT-IR) useful for probing the chemical and physical properties of materials.

2. Detailed SEM images of natural fluorapatite crystals indicate the presence of naturally included minerals (e.g., Ni), offering the possibility of studying natural analogs to waste-loaded apatite materials.

Keywords

Calcium phosphate; Fluorides; Fluorination; Hydroxyapatite; Phosphate minerals; Radioactive wastes — Storage; Separation (Technology); Zirconium compounds

Controlled Subject

Radioactive wastes--Storage; Separation (Technology); Zirconium compounds

Disciplines

Chemistry | Oil, Gas, and Energy | Physical Chemistry

File Format

pdf

File Size

61 KB

Language

English

Rights

COPYRIGHT UNDETERMINED. For more information about this rights statement, please visit http://rightsstatements.org/vocab/UND/1.0/

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