Exploring the heat-treated ammonium diuranate fingerprint for nuclear forensics.

Uranium ore concentrate plays an essential role in the fabrication of uranium dioxide. Uranium ore concentrate as ammonium diuranate (ADU) is an intermediate nuclear material, making it one of the materials of concern in nuclear forensics. In industrial processes, ADU was dried at the temperature range of 120 – 400 °C and the calcination process in the temperature range of 400 – 850 °C, which allows for changes in morphology and structure. The final product is very dependent on the starting material. The ADU powder from the pilot conversion plant (PCP) – BRIN needed to be characterized for its fingerprint. Heat treatment was varied at 250 °C, 300 °C, and 400 °C with an air atmosphere. Characterization included uranium content, morphological observations using a Scanning Electron Microscope (SEM), and revealing the phase composition using X-Ray diffraction (XRD). The results showed that the uranium content increased with increasing temperature, the highest at a temperature of 400 °C, where the uranium content is 79.66 ± 0.51%. Visually, the pore size of the powder is getting smaller, and the amount decreases with increasing temperature. In ADU powder, before heat treatment consists of two phases, and after the heat treatment forms three phases. The results of this characterization can be devoted to a nuclear forensics database of nuclear and radioactive materials. [ABSTRACT FROM AUTHOR]