Published July 1978 | Version v1
Report Metadata-only

Relationship of microstructural components in pyrocarbon coatings to fission product retention

Creators

  • 1. Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.)

Description

The influence of the microstructure of pyrocarbon coatings on the fission product permeability is discussed. The permeability of as-deposited and irradiated coatings for gases, Hg or Cs is strongly dependent on the microstructure of the as-deposited pyrocarbon. The Cs diffusion coefficient varies with the microstructure and the fast neutron fluence. The neutron induced release of gaseous fission product is due to microcracks formed in the high-density 'Mosaic' component. The fission gas release can be considered as a prestate of mechanical coating failure. Both failure mechanisms are due to low amounts of the porous 'fiber' component of the coating. (GSC)

Abstract (German)

Es wird der Einfluss der Mikrostruktur von Pyrokohlenstoff-Beschichtungen auf die Spaltproduktdurchlaessigkeit diskutiert. Die Durchlaessigkeit der so gelagerten und bestrahlten Beschichtungen fuer Gase, Hg oder Cs haengt stark von der Mikrostruktur des so gelagerten Pyrokohlenstoffs ab. Der Diffusionskoeffizent fuer Cs aendert sich mit der Mikrostruktur und der schnellen Neutronenfluenz. Die neutroneninduzierte Spaltgasfreisetzung haengt von in der hochdichten 'Mosaik'-Komponente gebildeten Mikrorissen ab. Die Spaltgasfreisetzung kann als ein Vorstadium eines mechanischen Versagens der Beschichtung angesehen werden. Beide Versagensmechanismen ruehren von dem geringen Anteil an den poroesen 'Faser'-Komponenten in der Beschichtung her. (GSC)

Additional details

Publishing Information

Imprint Title
Contributions for the fifth London international conference on carbon and graphite
Journal Page Range
p. 22-30.
Report number
Juel-Conf--25

Conference

Title
5. London international conference on industrial carbon and graphites.
Dates
18 - 22 Sep 1978.
Place
London, UK.

INIS

Country of Publication
Germany
Country of Input or Organization
Germany
INIS RN
10440843
Subject category
S36: MATERIALS SCIENCE;
Resource subtype / Literary indicator
Conference
Descriptors DEI
CESIUM; COATED FUEL PARTICLES; DIFFUSION; FAST NEUTRONS; FISSION PRODUCTS; MERCURY; MICROSTRUCTURE; NEON; NEUTRON FLUENCE; PERMEABILITY; PHYSICAL RADIATION EFFECTS; PYROLYTIC CARBON; VAPOR DEPOSITED COATINGS; VERY HIGH TEMPERATURE
Descriptors DEC
ALKALI METALS; BARYONS; CARBON; COATINGS; CRYSTAL STRUCTURE; ELEMENTARY PARTICLES; ELEMENTS; FERMIONS; FUEL PARTICLES; HADRONS; ISOTOPES; METALS; NEUTRONS; NONMETALS; NUCLEONS; RADIATION EFFECTS; RADIOACTIVE MATERIALS; RARE GASES