Crystals subjected to quenching or irradiation often develop a high concentration of vacancies, resulting in a supersaturated state. These vacancies interact with dislocations by migrating to their cores, where they are absorbed, merging with the half-plane associated with the dislocation’s edge component. As a result, the half-plane shortens, effectively driving the dislocation perpendicular to its slip plane in a process known as climb. This motion is driven by the significant energy gain when a vacancy joins the dislocation core, creating an osmotic force that acts on the dislocation normal to its line. This force is so strong that no obstacle can impede the dislocation’s climb. A pinned dislocation segment in a crystal with supersaturated vacancies bends and, at a certain level of supersaturation, forms loops. In this chapter, we analyze the effect of the process zone on this phenomenon. Furthermore, in such crystals, prismatic loops are subjected to radial osmotic pressure, which leads to their instability at a critical radius. We examine the contribution of the dislocation’s process zone to determining this critical radius. This chapter analyzes the evolution of elements of the dislocation ensemble—Bardeen-Herring sources, and prismatic loops—in a crystal supersaturated with vacancies. This supersaturation can occur due to rapid cooling during quenching or as a result of irradiation. The vacancies accumulate at dislocations, causing them to climb (Korzhenevskii and Lisachenko, 1990).