PMK-2 projects were initiated at the very beginning of the 1980s, parallel to the start-up of the Paks nuclear power plant of VVER-440/213 type. The main aims of the projects were to get experimental information on transients and accidents anticipated to occur in the plant, and to apply the experimental results obtained for validation of thermohydraulic system codes applied to the national licensing analysis of the Paks nuclear power plant. Experiments simulating the off-normal events occurring in the plant had been performed in the PMK-2 facility, the integral-type thermohydraulic model of the plant. At that time, PMK-2 was the first and only plant model for VVERs. The whole spectrum of design basis accidents had been simulated and results were applied to validate thermohydraulic system codes for VVER-440/213 applications, with the participation of experts from 29 countries. The validated codes were applied to the reassessment of the safety of the Paks nuclear power plant and to all the modifications performed in the plant. Results published in Volume I and II are offered to the present and future generation of specialists in areas of accident analyses of water cooled reactors.