  The properties of recently predicted thermally fissile Th and U isotopes are
studied within the framework of relativistic mean field (RMF) approach using
axially deformed basis. We calculated the ground, first intrinsic excited state
and matter density for highly neutron-rich thorium and uranium isotopes. The
possible modes of decay like $\alpha$-decay and $\beta$-decay are analyzed. We
found that the neutron-rich isotopes are stable against $\alpha$-decay, however
they are very much unstable against $\beta$-decay. The life time of these
nuclei predicted to be tens of second against $\beta$-decay. If these nuclei
utilize before their decay time, a lots of energy can be produced within the
help of multi-fragmentation fission. Also, these nuclei have a great
implication in astrophysical point of view. The total nucleonic densities
distribution are calculated, from which the clusters inside the parent nuclei
are determined. %Most of the thorium isotopes are $\alpha$ emitters, where as
some %of them have short half-lives. In some cases, we found the isomeric
states with energy range from 2 to 3 MeV and three minima in the potential
energy surface of $^{228-230}$Th and $^{228-234}$U isotopes.
