Abstracts Book - IMRC 2018

• SE3-O002
OXIDATION OF PYROLYTIC CARBON COATINGS AND NUCLEAR
GRADE GRAPHITE AT TEMPERATURES BETWEEN 700 AND 1000
°C
David Jacob Navarro Solis 1 , Eddie Lopez Honorato 1
1 Centro de Investigación y de Estudios Avanzados del IPN - CINVESTAV Unidad Saltillo,
Céramica, Mexico.
The TRISO coated fuel particle (tristructural isotropic) has a uranium oxide
kernel coated with three layers of pyrolytic carbon (PyC) and one of silicon
carbide (SiC). Although originally designed for the High Temperature Reactor
(HTR), this fuel is currently being considered as accident tolerant fuel for the
Light Water Reactor (LWR). For this reason, is of paramount important to
understand the stability of these coatings under oxidising conditions. In this
work we compare the oxidation behaviour of different PyC coatings and nuclear
grade graphite in air at temperatures between 700 and 1000 °C using
thermogravimetry and differential scanning calorimetry. Samples have also
been characterised by Raman spectroscopy and SEM. The thermogravimetric
analysis showed that nuclear grade graphite (NBG-18 and R6650) had a weight
loss of 1.9 and 3.2% at 700 °C, whereas at 1000 °C the oxidation increased up to
14 and 9%, respectively. PyC showed a higher weight loss regardless of density
compared to graphite. PyCs with an initial density of 1.9 and 1.7 g/cm 3 showed
a weight loss of 3.5 and 10% at 700°C, and 17 and 26% at 1000 °C, respectively.
We discussed the effect of microstructure on the oxidation rate of each material.
Acknowledgment:
I want to thank the National Council of Science and Technology for the
scholarship granted to do the doctorate in the Center for Research and
Advanced Studies of the National Polytechnic Institute, Saltillo Unit.
Keywords: TRISO fuel particle, Pyrolytic carbon, Nuclear grade graphite.
Presenting authors email: david.navarro@cinvestav.mx