 A further 6 plants lie within zone 2.The current process for evaluating the seismic hazard for a nuclear plant is set out in "Règle Fondamentale de Sûreté" (Fundamental Safety Rule) RFS 2001-01, published by the Institute for Radioprotection and Nuclear Safety, which uses more detailed seismotectonic zones.RFS 2001-01 replaced RFS I.2.c, published in 1981, however it has been criticised for continuing to require a deterministic assessment (rather than a probabilistic approach) that relies primarily on the strongest 'historically known' earthquake near a site.