The main purpose of the project was to extend the scope of simulation in terms of normal operation modes, anticipated deviations from the normal operation conditions, and accident conditions, together with significant increase in the quality of simulation for the Nuclear Steam Supply System (NSSS) within the extended simulation scope. In addition, enhancement of the simulator operational features was envisaged, as well as extension of its capacities, so as to satisfy the user requirements to the training process or for other practical purposes, including the checkup of emergency instructions and/or procedures.