Launched in 1974, the second generation of nuclear power plants owned and operated by EDF was unique in its scope and degree of standardization. It comprised 6 series of PWR units:
• 6 “CP0” 900 MWe Plants (including the first 3 ordered before 1974)
• 18 “CP1” 900 MWe Plants
• 20 “CP2” 900 MWe Pants
• 6 “P4” 1300 MWe Plants
• 14 “P’4” 1300 MWe plants
• 4 “N4” 1450 MWe Plants
As a matter of fact, all 34 CPx units identical NSSS and differ only in the nonnuclear balance of plant BOP. The same applies to P4 and P’4.
This high degree of standardization allowed a drastic cost reduction along the series CP and P. The N4 series was too short to exhibit any significant series effect.
Table 5.3.2 (Continued)
An additional cost reduction came from building systematically several units (2 to 6) along one another on the same site. Standardization allows also a very efficient return of experience because any lesson learned on one unit is completely suitable to be applied on all its identical twins. Standardization facilitates the training of operation and maintenance teams who can move from one plant to the other without losing their efficiency.
On the other hand, going standardized was a bold decision because of the risk of common mode failure… And some such failures did happen, but only in the process of ageing: they could therefore be repaired during the normal periodical outages before each unit reached the “critical age” for a given defect to appear.
The huge planned construction program allowed Framatome to invest in very modern construction plants and facilities, dimensioned to accommodate eight NSSS per year, including two for potential exports. These modern facilities allowed reducing fabrication costs by fully taking advantage of the standardization: what could be called a “virtuous” circle.
With the connection of Civaux 2, the last of the N4 series to the grid, the “quantitative program” was completed in 2000.
The first 900 series were actually plants built under license, duplicated from an existing “lead plant” already operating in the United States. But after 1974, in stark contrast to the French situation, the US nuclear program ran into deep troubles (which are beyond the scope of this paper). As a result, Paluel 1, the first of the P4 series, had to be completed far in advance of South Texas 1, its supposed “lead plant”. Westinghouse was no longer in a position to act as a true licensor, and Framatome terminated prematurely the license agreement in early 1981. From then on, the PWR technology was recognized to be entirely “naturalized French”, and the N4 technology is genuinely French.
Table 5.3.2 recapitulates the main features of the French NPP in operation and in construction.