  We investigate how strong a hypothetical 1S0 bound state of two neutrons
would affect different observables in the neutron-deuteron reactions. To that
aim we extend our momentum space scheme of solving three-nucleon Faddeev
equations to incorporate in addition to the deuteron also the 1S0 dineutron
bound state. We discuss effects induced by dineutron on the angular
distribution of the neutron-deuteron elastic scattering and cross sections of
the deuteron breakup. A comparison to the available data for neutron-deuteron
total cross sections and elastic scattering angular distributions cannot
decisively exclude a possibility that the two neutrons can form 1S0 bound
state. However, the strong modifications of a final-state-interaction peak of
the neutron-deuteron breakup when changing from negative to positive values of
the neutron-neutron scattering length seems to exclude existence of dineutron.
