Magnetic resonance as a structural probe of a uranium (VI) sol-gel process

Conference · Sun Jan 01 00:00:00 EST 1989

OSTI ID:7116108

King, C M; Thompson, M C; Buchanan, B R ^[1]; King, R B ^[2]; Garber, A R ^[3]

---

1. Westinghouse Savannah River Co., Aiken, SC (United States)
2. Georgia Univ., Athens, GA (United States). Dept. of Chemistry
3. 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; USDOE, Washington, DC (United States)
• DOE Contract Number: AC09-89SR18035
• OSTI ID: 7116108
• 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
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
URANIUM DIOXIDE
SYNTHESIS
AMINES
AMMONIUM URANATES
CARBON 13
CHEMICAL REACTION KINETICS
HYDROGEN
HYDROLYSIS
MICROSPHERES
NITROGEN 15
NUCLEAR MAGNETIC RESONANCE
OXYGEN 17
SOL-GEL PROCESS
URANYL COMPOUNDS
URANYL NITRATES
ACTINIDE COMPOUNDS
AMMONIUM COMPOUNDS
CARBON ISOTOPES
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
EVEN-ODD NUCLEI
ISOTOPES
KINETICS
LIGHT NUCLEI
LYSIS
MAGNETIC RESONANCE
NITRATES
NITROGEN COMPOUNDS
NITROGEN ISOTOPES
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
REACTION KINETICS
RESONANCE
SOLVOLYSIS
STABLE ISOTOPES
URANATES
URANIUM COMPOUNDS
URANIUM OXIDES
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication
050700 - Nuclear Fuels- Fuels Production & Properties
665100 - Nuclear Techniques in Condensed Matter Physics - (1992-)