7. Conclusion

We successively presented the general operating principles of PWR units, the limits to be respected, the regulation and protection systems, and finally the transients typical of normal operation. In particular, it was explained how the units are able to modulate their power to meet the needs of the power grid. As we went along, we pointed out the progress that has made it possible to go from 900 MWe to 1,600 MWe units (EPR), while retaining the same reactor concept:

• GV design ;

• digital control technologies ;

• backup system architecture ;

• fixed internal neutron instrumentation.