Premium
Kernel Migration for HTGR Fuels from the System Th‐U‐Pu‐C‐O‐N
Author(s) -
LINDEMER T. B.,
PEARSON R. L.
Publication year - 1977
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1977.tb16082.x
Subject(s) - pyrolytic carbon , materials science , diffusion , actinide , fission , fission products , radiochemistry , analytical chemistry (journal) , nuclear chemistry , chemistry , thermodynamics , pyrolysis , nuclear physics , physics , neutron , chromatography , organic chemistry
Nuclear fuels for the high‐temperature gas‐cooled reactor (HTGR) consist of spherical kernels of actinide compounds contained in gaslight pyrolytic carbon and SiC. The fuel kernels migrate up the temperature gradient and into the coating layers. A theoretical analysis of in‐reactor migration data indicates that a solid‐state diffusion process controls the migration rate in fissioned Th 0.84 U 0.16 C 2 , UO 2 , ThO 2 , PuO 2‐x , and Th 0.8 U 0.2 O 2 particles. The theoretically based kernel migration coefficient (KMC) measured in units (cm/s) °K 2 ( o K/cm)‐ 1 , is thus used to correlate the laboratory and in‐reactor data. The KMC values for Pu‐containing particles may be dependent on the initial and in‐reactor O/Pu values. The other in‐reactor KMC values were apparently not dependent on the extent of fission, the fission of either 233 U or 235 U, or the presence of an SiC coating layer. Laboratory KMC values were obtained for unirradiated ThO 2 , UO 1.65 N 0.25 ,UC 2 ThC 2 , and Th 0.84 U 0.16 C 2 particles and generally appeared to be consistent with in‐reactor data.