[en] Fission-product decay energy-release rates were measured for thermal-neutron fission of ²³⁵U. Samples of mass 1 to 10 μg were irradiated for 1 to 100 s by using the fast pneumatic-tube facility at the Oak Ridge Research Reactor. The resulting beta- and gamma-ray emissions were counted for times-after-fission between 2 and 14,000 s. The data were obtained for beta and gamma rays separately as spectral distributions, N(E/sub γ/) vs E/sub γ/ and N(E/sub β/) vs E/sub β/. For the gamma-ray data the spectra were obtained with a NaI detector, while for the beta-ray data the spectra were obtained by using an NE-110 detector with an anticoincidence mantle. The raw data were unfolded to provide spectral distributions of moderate resolution. These distributions are given in graphical and tabular form as differential cross-section values of d sigma/dE/fission for gamma-ray energy intervals ranging from 10 keV for E/sub γ/ less than 0.18 MeV to 100 keV for E/sub γ/ greater than 6.8 MeV, and beta-ray energy intervals ranging from 20 keV for E/sub β/ less than 0.25 MeV to 160 keV for E/sub β/ greater than 6.4 MeV. Counting-time intervals range from 1 s for times-after-fission (t/sub w/) less than 6 s to 4000 s for t/sub w/ equals 10⁴ s. The graphical representations also include calculated spectra using summation methods and the ENDF/B-IV fission yield and decay scheme data base. 92 figures, 87 tables