Nuclear spectroscopy experiments were performed for 100g metallic uranium rod enriched to 93% 235U, in order to establish and characterize the most prominent γ-rays in the natural decay series and photofission reaction. Single γ-ray spectra and γ–γ coincidences measurements were conducted before irradiation. The uranium sample was subsequently irradiated with 15MeV bremsstrahlung photons. Relative intensities of γ-lines and several values of half-lives of the fission fragments decays were determined. The obtained information can be utilized in detection of smuggled nuclear materials and characterization of bulky nuclear waste packages. •The γ-lines in the natural decay series and photofission of highly enriched uranium were studied.•Single γ-ray spectra, γ–γ coincidences and photofission of uranium were investigated.•High-energy γ lines were identified as indicators of the presence of a uranium.•Enrichment of a U sample was roughly estimated.