  The main physical goal of the project is to search with reactor antineutrinos
for small mixing angle oscillations in the atmospheric mass parameter region
around {\Delta}m^{2}_{atm} ~ 2.5 10^{-3} eV^2 in order to find the element
U_{e3} of the neutrino mixing matrix or to set a new more stringent constraint
(U_{e3} is the contribution of mass-3 state to the electron neutrino flavor
state). To achieve this we propose a "one reactor - two detector" experiment:
two identical antineutrino spectrometers with $\sim$50 ton liquid scintillator
targets located at ~100 m and ~1000 m from the Krasnoyarsk underground reactor
(~600 mwe). In no-oscillation case ratio of measured positron spectra of the
\bar{{\nu}_e} + p \to e^{+} + n reaction is energy independent. Deviation from
a constant value of this ratio is the oscillation signature. In this scheme
results do not depend on the exact knowledge of the reactor power, nu_e
spectra, burn up effects, target volumes and, which is important, the
backgrounds can periodically be measured during reactor OFF periods. In this
letter we present the Krasnoyarsk reactor site, give a schematic description of
the detectors, calculate the neutrino detection rates and estimate the
backgrounds. We also outline the detector monitoring and calibration
procedures, which are of a key importance. We hope that systematic
uncertainties will not accede 0.5% and the sensitivity U^{2}_{e3} ~4 10^{-3}
(at {\Delta}m^{2} = 2.5 10^{-3} eV^2) can be achieved.
