[en] This article presents the design, specificities and innovating features of the control room of the N4-type PWR. A brief description of control rooms of previous 900 MW and 1300 MW -type PWR allows us to assess the change. The design of the first control room dates back to 1972, at that time 2 considerations were taken into account: first the design has to be similar to that of control rooms for thermal plants because plant operators were satisfied with it and secondly the normal operating situation has to be privileged to the prejudice of accidental situations just as it was in a thermal plant. The turning point was the TMI accident that showed the weight of human factor in accidental situations in terms of pilot team, training, procedures and the ergonomics of the work station. The impact of TMI can be seen in the design of 1300 MW-type PWR. In the beginning of the eighties EDF decided to launch a study for a complete overhaul of the control room concept, the aim was to continue reducing the human factor risk and to provide a better quality of piloting the plant in any situation. The result is the control room of the N4-type PWR. Today the cumulated feedback experience of N4 control rooms represents more than 20 years over a wide range of situations from normal to incidental, a survey shows that the N4 design has fulfilled its aims. (A.C.)

[en] Large companies like EDF or Framatome-ANP have to face a big turnover of staff because a lot of employees are expected to retire by 2015. They have drawn special training policies in order to avoid the loss of practical knowledge particularly in the field of maintenance. Technological progress, bringing more flexibility and reactivity to the power demand, are constant challenges for nuclear industry. In this series of short articles major improvements are reviewed. A new cladding material: the M5 alloy (zirconium + niobium + oxygen) can undergo up to 78 GWj/tU burnup and presents high resistance to corrosion, low generation of hydrogen, good behaviour in power ramps and in accidental situations. Progress in instrumentation and the broad use of digit technology have also led to improvements in reactor monitoring systems. Studies concerning the hydrogen risks back the decision to implement in each reactor unit a hydrogen catalytic re-combiner whose role will be to reduce the concentration of gaseous hydrogen through the production of water. (A.C.)