Thermophysical Properties of Uranium-Based Niobium and Zirconium Alloys from 23 A°C to 175 A°C

The thermal diffusivities of uranium alloys were measured by the laser-flash method between room temperature and 448 K. In recent years, several UZrNb alloys have been studied by many researchers and it was shown that additions of niobium and zirconium improve the properties of uranium-based alloys. The purpose of this article is to summarize the thermophysical properties of two uranium alloys that have been studied by CDTN in a program of development of fuel for low-power reactors. The nominal compositions of the studied alloys are U4Zr6Nb and U3Zr9Nb. The results obtained by the original laser-flash method and by the mathematical model developed by the laboratory were compared to the literature data. The adaptive Monte Carlo method was used to obtain the endpoints of the probabilistically symmetric 95% coverage interval for estimates of the output quantities and its uncertainties.