BEHAVIORS OF MOLYBDENUM IN UO2FUEL MATRIX

• DOI: 10.5516/net.2011.43.3.309
• Publication Date: 2011-09-15T12:03:25Z
• Authors: Yeong-Keong Ha; Jong-Goo Kim; Yang-Soon Park; Soon-Dal Park; Kyu-Seok Song
• Keywords: Burnup; Nuclear Fuel; Nuclear fission product; Uranium dioxide

Molybdenum is the most abundant fission product since its fission yield is equivalent to that of xenon, and it has a very special role in the chemistry of nuclear fuel because it influences the oxygen potential of UO₂ fuel. In this study, the distribution of molybdenum in spent UO2 fuel specimens with 33.3, 41.0 and 57.6 GWd/tU burnup was measured by a LA-ICP-MS system and the reproducibility of the measured data was obtained. The Mo distribution was almost constant along the radius of a fuel except an increase at the periphery of the fuel. It showed a drop in reproducibility with relatively high deviation of measured values for the highest burnup fuel. To explain this, the state of molybdenum in a UO₂ matrix and its effect on the oxidation behavior of UO₂ were investigated. The low reproducibility was explained by the segregation of molybdenum, and the inhibition of oxidation by the molybdenum was also observed.