Magnetic resonance as a structural probe of a uranium (VI) sol-gel process
- Westinghouse Savannah River Co., Aiken, SC (United States)
- Georgia Univ., Athens, GA (United States). Dept. of Chemistry
- South Carolina Univ., Columbia, SC (United States). Dept. of Chemistry
NMR investigations on the ORNL process for sol-gel synthesis of microspherical nuclear fuel (UO{sub 2}), has been useful in sorting out the chemical mechanism in the sol-gel steps. {sup 13}C, {sup 15}N, and {sup 1}H NMR studies on the HMTA gelation agent (Hexamethylene tetramine, C{sub 6}H{sub l2}N{sub 4}) has revealed near quantitative stability of this adamantane-like compound in the sol-Gel process, contrary to its historical role as an ammonia source for gelation from the worldwide technical literature. {sub 17}0 NMR of uranyl (UO{sub 2}{sup ++}) hydrolysis fragments produced in colloidal sols has revealed the selective formation of a uranyl trimer, [(UO{sub 2}){sub 3}({mu}{sub 3}-O)({mu}{sub 2}-OH){sub 3}]{sup +}, induced by basic hydrolysis with the HMTA gelation agent. Spectroscopic results show that trimer condensation occurs during sol-gel processing leading to layered polyanionic hydrous uranium oxides in which HMTAH{sup +} is occluded as an ``intercalation`` cation. Subsequent sol-gel processing of microspheres by ammonia washing results in in-situ ion exchange and formation of a layered hydrous ammonium uranate with a proposed structural formula of (NH{sub 4}){sub 2}[(UO{sub 2}){sub 8}O{sub 4}(OH){sub 10}] {center_dot} 8H{sub 2}0. This compound is the precursor to sintered U0{sub 2} ceramic fuel.
- Research Organization:
- Westinghouse Savannah River Co., Aiken, SC (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC09-89SR18035
- OSTI ID:
- 10164513
- Report Number(s):
- WSRC-RP-89-1285; CONF-900466-107; ON: DE92017909
- Resource Relation:
- Conference: Spring meeting of the Materials Research Society (MRS),San Francisco, CA (United States),16-21 Apr 1990; Other Information: PBD: [1989]
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
URANIUM DIOXIDE
SYNTHESIS
NUCLEAR MAGNETIC RESONANCE
SOL-GEL PROCESS
AMINES
CARBON 13
NITROGEN 15
HYDROGEN
URANYL NITRATES
OXYGEN 17
HYDROLYSIS
MICROSPHERES
CHEMICAL REACTION KINETICS
AMMONIUM URANATES
URANYL COMPOUNDS
360201
050700
665100
PREPARATION AND FABRICATION
FUELS PRODUCTION AND PROPERTIES
NUCLEAR TECHNIQUES IN CONDENSED MATTER PHYSICS