Flux and spectrum of reactor antineutrinos

In order to perform reactor experiments aimed at studying the nature of the neutrino and measurements in the realms of geo- and astrophysical neutrinos and to meet practical requirements in this field, it is highly desirable to obtain deeper insight into the operation of nuclear reactors as a source of antineutrinos. The fluxes and spectra of neutrinos from a reactor in the on and off modes and from a reservoir intended for storing a spent reactor fuel and situated near the reactor being considered are calculated. Features that are peculiar to the flux and spectrum of reactor antineutrinos and which are of importance for implementing and interpreting experiments, but which were disregarded previously, are analyzed here.