  We calculate the ground, first intrinsic excited states and density
distribution for neutron-rich thorium and uranium isotopes, within the
framework of relativistic mean field(RMF) approach using axially deformed
basis. The total nucleon densities are calculated, from which the
cluster-structures inside the parent nuclei are determined. The possible modes
of decay, like {\alpha}-decay and \b{eta} -decay are analyzed. We find the
neutron-rich isotopes are stable against {\alpha}-decay, however they are very
much unstable against \b{eta} -decay. The life time of these nuclei predicted
to be tens of second against \b{eta} -decay.
