  Using equations, governing np pairing correlations in S=1, T=0 pairing
channel (PRC 63 (2001) 021304(R)), it is shown that at low densities equations
for the energy gap in the spectrum of quasiparticles and chemical potentials of
protons and neutrons allow solutions with negative chemical potential. This
corresponds to appearance of Bose--Einstein condensate (BEC) of deuterons in
low density region of nuclear matter.
