[natmaka]

Before the N4 there is no question, read page 12 (first paragraph) and 13 (first paragraph): https://archive.wikiwix.com/cache/index2.php?url=http%3A%2F%...

The N4 double containment is a mainly quantitative change, as are all the other changes you mentioned: the very architecture remains the same, as do the associated exploitation processes.

Those modifications were big enough to justify seeing the N4 as a "new design" because the French worked hard to master this design, and since 1981 (Nuclear Technical Cooperation Agreement, NTCA) Westinghouse & the French formally exchanged know-how. Moreover Westinghouse didn't work on the N4 and it escaped the Westinghouse license (which expired in 1992). However the very design isn't disruptive. As for this approach efficiency the note #17 seems pertinent.

The newest design ('EPR') also is a mere evolution, as officially stated: https://www.irsn.fr/savoir-comprendre/surete/presentation-hi...