4.5.1 Characterization of nuclear power plants in operation

The structure of the individual types of nuclear power plants in operation includes WWER-440 /V-230 reactor units (2 units at NPP Bohunice) and WWER-440/V-213 reactor units (2 units at NPP Bohunice and units at NPP Mochovce). Two WWER-440/V-213 units are under construction at Mochovce ( their construction was however frozen in mid-90s and the facility was preserved). The V-230 reactors are quite different from V-213 reactors as far as their structure and safety elements are concerned, whereas both types of V-213 reactors at NPP Bohunice and Mochovce are based on the same design concept. The V-213 reactors at NPP Mochovce showed a number of improvements in their original design, and also included some new safety elements. During the construction of NPP Mochovce, the safety standard of the original design was reassessed, and a number of safety relevant improvements was introduced.

In the framework of the extensive gradual reconstruction, the project base of WWER-440/V-230 units at Bohunice was significantly supplemented and upgraded, so that the units may presently be considered advanced type of the original WWER-440/V-230 project.