TITLE:
Thermodynamic Assessment of UO2 Pellet Oxidation in Mixture Atmospheres under Spent Fuel Pool Accident
AUTHORS:
Dong-Joo Kim, Jong Hun Kim, Keon Sik Kim, Jae Ho Yang, Sun Ki Kim, Yang-Hyun Koo
KEYWORDS:
Spent Nuclear Fuel Pool, UO2 Fuel Pellet, UO2 Oxidation, Oxygen Partial Pressure
JOURNAL NAME:
World Journal of Nuclear Science and Technology,
Vol.5 No.2,
April
15,
2015
ABSTRACT: For an analysis of the oxidation behavior of UO2 nuclear fuel
pellet under a loss of water coolant accident in a spent nuclear fuel pool of
an LWR, thermodynamic assessments of UO2 oxidation were carried out
under various atmospheric conditions. In a steam atmosphere, it was assessed
that UO2 would not be fully oxidized into U3O8 due to the relatively lower oxygen partial pressure, while UO2 will
be fully oxidized into U3O8 in an air atmosphere. In an
air and steam mixture atmosphere, the UO2 oxidation was dominantly
affected by the air volumetric fraction, because of the relatively higher
oxygen partial pressure of air. In addition, the effect of H2 volumetric fraction on the oxygen partial pressure under a mixture atmosphere
was calculated, and it was revealed that UO2 pellet oxidation could
be reduced above the critical value of H2 volumetric fraction.