A study of antineutrino spectra from spent nuclear fuel at Daya Bay

The Daya Bay Reactor Antineutrino Experiment is designed to determine the as yet unknown neutrino mixing angle, θ13, by measuring the disappearance of electron antineutrinos from several nuclear reactor cores. The projected sensitivity in sin2 (2θ13) of better than 0.01 at a 90% CL should be achieved after three years of data-taking. Antineutrinos emitted from spent nuclear fuel (SNF) distort the soft part of the energy spectrum. In this article, a calculation of the antineutrino spectra from the long-life isotopes in SNF is performed. A non-equilibrium generation of long half-life isotopes during the running time of the reactor is also analyzed. Finally, we show that the antineutrino event rate contribution from SNF, which has been stored in the SNF pool for several years, may be non-negligible. (authors)