The first EPR project in France (Flamanville-3) had problems documented in an official report (dubbed 'Folz', per the name of its main author), sadly AFAIK it wasn't translated into English: https://www.economie.gouv.fr/rapport-epr-flamanville

A piece about it: https://www.archyde.com/the-folz-report-draws-up-a-severe-as...

This study may also offer some hints: https://www.sciencedirect.com/science/article/pii/S030142151...