Preparation of monophasic [NZP] radiophases: Potential host matrices for the immobilization of reprocessed commercial high-level wastes
- Los Alamos National Lab., NM (United States)
- Pennsylvania State Univ., University Park, PA (United States). Intercollege Materials Research Lab.
The compositional flexibility of the sodium zirconium phosphate (NaZr{sub 2}(PO{sub 4}){sub 3}) structure has been exploited in the design of monophasic radiophases capable of immobilizing the most common cations associated with reprocessed high-level commercial waste streams. Highly crystalline, monophasic members of the NaZr{sub 2}(PO{sub 4}){sub 3} structural family ([NZP]) have been prepared with conventional processing methods and equipment. These radiophases were tailored to accommodate 10--20 wt% modified PW-4b simulated calcine as single phases isostructural with NaZr{sub 2}(PO{sub 4}){sub 3}. To meet the challenge of designing monophasic materials capable of accommodating the chemical complexity of PW-4b, an ionic substitution scheme based on crystal chemical principles was developed. The radiophases were prepared with inexpensive, inorganic precursors and a solution sol-gel method; these materials were heat treated and/or sintered under a variety of conditions to determine the optimum conditions for single phase [NZP] formation. X-ray powder diffraction provided valuable information that was used to assess the suitability of the ionic substitution model developed in this investigation. The results of this investigation suggest that monophasic [NZP] radiophases capable of accommodating 10--20 wt% modified PW-4b simulated calcine may be continuously processed with conventional ceramic processing methods and equipment. Moreover, the relatively low temperatures involved and the reproducibility of the process make [NZP] radiophases economically attractive hosts for radioactive and heavy metal industrial wastes.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- OSTI ID:
- 572093
- Report Number(s):
- CONF-961202-; TRN: 98:003716
- Resource Relation:
- Conference: 1996 Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 2-6 Dec 1996; Other Information: PBD: 1997; Related Information: Is Part Of Scientific basis for nuclear waste management XX; Gray, W.J. [ed.] [Pacific Northwest National Lab., Richland, WA (United States)]; Triay, I.R. [ed.] [Los Alamos National Lab., NM (United States)]; PB: 1389 p.; Materials Research Society symposium proceedings, Volume 465
- Country of Publication:
- United States
- Language:
- English
Similar Records
NANOSTRUCTURED CERAMICS AND COMPOSITES FOR REFRACTORY APPLICATIONS IN COAL GASIFICATION
Sodium zirconium phosphate (NZP) as a host structure for nuclear waste immobilization: A review