Measurement of Gd content in (U,Gd)O2 using thermal gravimetric analysis

We propose a simple and precise method for measuring the Gd content in the (U,Gd)O2 pellet by only measuring the weight variation of the pellet during thermal heat treatment in air. The (U,Gd)O2 fuel pellets were oxidized at 475 °C, subsequently heat treated at 1300 °C, and then cooled to room temperature in air. The accompanying weight variations were measured using thermo gravimetric analysis (TGA). The measured weight variations were mathematically analyzed with reference to the successive phase reactions during the heat treatment. This method provides an advantage in that the rare-earth element content including Gd can be measured using relatively simple equipment such as an electric furnace and a balance.