The assembling of galaxy clusters by mergers and accretions happens concurrently with the quest of these systems to reach virialization. Depending on the environment where the cluster resides, each of these processes may predominate, and the time the system will take to reach its final dynamical state may extend longer. In a relatively isolated environment, the cluster will only pass a single virialization process, while in the core of a supercluster it will go through different unrelaxed/relaxed states, till reaching a maximum size, the same way as fossil D galaxies clean completely their surroundings at some time. In this work we study the case of these probable largest clusters that someday will reach equilibrium, that is, we are searching for what we call "nucleation zones", which are these supercluster cores that are expected to still collapse despite of the accelerated expansion of the Universe. We have studied a sample of about 50 rich superclusters of galaxies (multiplicity ≥ 5), with z ≤ 0.15, for identifying their nucleation zones and characterizing their structure. We use mainly the entropy of these structures, calculated based on the properties and distribution of galaxies and galaxy groups and clusters inside these cores, to delimit the collapse regions. Here we present the preliminary results of this study. We have found that some superclusters possess more than one nucleation zone. Our results agree with the very few cases previously studied according to the literature.