Porosity correction factor for the thermal conductivity of porous materials (LWBR Development Program)

Technical Report · Sun Feb 01 04:00:00 EST 1970

OSTI ID:6745891

Marino, G P

The variation of the porosity correction factor, ..beta.., with temperature and pore shape was studied by using the Fricke equation for the thermal conductivity of a two-phase medium containing the second phase as randomly distributed ellipsoids. Since the temperature variation occurred via the parameter ..gamma.. = K/sub pore//K/sub 100/, the conductivity of the pores was also calculated for various gas contents in the pores. The thermal radiation contribution to pore conduction was also included. The effect of pore shape was determined via the axial ratio, epsilon, of oblate or prolate ellipsoidal pores. The results are presented graphically in curves showing the variation of ..beta.. with ..gamma.. and epsilon. The above model was applied to actual conductivity data of ThO/sub 2/ and ThO/sub 2/-UO/sub 2/ specimens in an effort to correlate the general porous structure typical of ceramic fuels to the parameters (epsilon and ..gamma..) in the Fricke equation. It was shown that the ..beta.. factor for ceramic fuels could be related to their general microstructure and pore conductivity in a self-consistent mathematical framework. The technique, therefore, minimized much of the guesswork heretofore required in estimating the porosity correction factor. (NSA 24: 27828)

• Research Organization: Bettis Atomic Power Lab., Pittsburgh, PA (USA)
• DOE Contract Number: AT(11-1)-GEN-14
• OSTI ID: 6745891
• Report Number(s): WAPD-TM-807
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ACTINIDE COMPOUNDS
BREEDER REACTORS
CHALCOGENIDES
LWBR TYPE REACTORS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POROSITY
REACTORS
THERMAL CONDUCTIVITY
THERMAL REACTORS
THERMODYNAMIC PROPERTIES
THORIUM COMPOUNDS
THORIUM OXIDES
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM OXIDES
VOIDS
WATER COOLED REACTORS
WATER MODERATED REACTORS