  The neutron-rich nuclei 130Cd and 206Hg, so important in the astrophysical
processes, may also be useful in tracking the evolution of nuclear shell gaps
as one traverses the neutron-rich region. The high spin 8+ isomer in 130Cd and
the 10+ isomer in 206Hg turn out to be the lampposts, which may shed light on
the shell gaps and validity of the seniority scheme in the neutron-rich
systems. We explore the robustness of the N=82 and N=126 magic numbers in the
neutron-rich 130Cd and 206Hg nuclides, respectively. A parallel between the two
nuclides in terms of the high-spin isomers allows us to investigate these
waiting-point nuclei, which have limited experimental data, by using the
concept of seniority as the stepping stone. In this paper, we report large
scale shell model calculations by using the available realistic effective
interactions derived from the Charge Dependent Bonn potential through the
renormalized G matrix. We also explore if any change in the interaction is also
required to consistently explain both the level structures as well the B(E2)
values. A structural similarity between the 8+ isomer in 130Cd and the 10+
isomer in 206Hg is noticed due to goodness of seniority. They are found to
possess a maximally aligned, seniority v = 2 configuration from their
respective intruder orbits. No shell quenching seems to be needed for the
seniority isomers in these nuclei. Therefore, N=82 and 126 appear to be very
robust magic numbers even in the neutron-rich region.
