Development of the installment for measuring melting temperature of nuclear fuels with laser surface melting method

Harada, Makoto; Arima, Tatsumi*

Melting temperature of nuclear fuels is important for safety assessment in nuclear reactor. In conventional method, they were measured using a metallic capsule, but a small extent of reactions was observed. In this study, laser surface melting method was applied. This method is to melt about 1 mm diameter of sample's surface, so container isn't needed. On the other hand, this method measures temperature from the sample directly, so its emissivity has to be determined. Therefore, some devices was used to measure its emissivity. In this study, Platinum and Black ZrO were used as a reference and a surrogate material, respectively. Using integrating sphere, melting temperature of Platinum was obtained at 7% lower than reference value and of Black ZrO was enabled to obtained with changing the condition of laser heating. Using multichannel spectrometer, it was calibrated using a blackbody furnace and thermal radiation spectrum of samples in freezing point was obtained.