- 95 - Belleville P4 VD2 RFS 2001-01 For the standard design, the DBE encompasses the earthquake resulting from RFS 2001-01. For the civil engineering reinforcements bars on the nuclear island and the site structures, the NRC 0.1 g spectrum entails slight overshoots beyond 4.5 Hz. Studies have confirmed that these overshoots are covered by the structural design margins. Cattenom 1-2-3 P4 VD2 RFS 2001-01 The DBE encompasses the earthquakes resulting from RFS I-2-C and 2001-01. Cattenom 4 P4 VD1 RFS I-2-C The DBE encompasses the earthquakes resulting from RFS I-2-C and 2001-01. Golfech P4 VD1 RFS I-2-C The DBE encompasses the earthquakes resulting from RFS I-2-C and 2001-01. Nogent P4 VD2 RFS 2001-01 The DBE encompasses the earthquakes resulting from RFS I-2-C and 2001-01. Penly P4 VD1 RFS I-2-C The DBE encompasses the earthquakes resulting from RFS I-2-C and 2001-01. Civaux N4 Before VD1 RFS I-2-C Civaux was initially designed on the basis of RFS I2-C. During the preparations for VD1, the facility underwent a seismic check resulting from RFS 2001-01. DBE overshoots beyond 5.5 Hz were brought to light. The licensee conducted studies to show that there was no significant impact on the buildings and equipment of the nuclear island and site structures, other than the BAS/BL equipment. Additional studies are in progress, as part of the preparations for the ten-yearly outage, to check the seismic qualification of the BAS/BL equipment. * For Fessenheim, the need for seismic reinforcement is not linked to a reassessment of the hazard, but to the implementation of new paraseismic calculation methods performed during the periodic safety reviews (see § 2.1.2). ** The Cruas site has the particularity of being built on a basemat resting on paraseismic supports, which considerably reduces the seismic loadings applied to the structures and equipment of the nuclear island, lowering the frequency of the island between 1 and 1.5 Hz. It can be seen that the main DBE overshoots are, pursuant to RFS 2001-01, due to: the use of a fixed minimum earthquake defined conventionally for zones with very low seismicity (Dampierre, Belleville, Saint Laurent), a reassessment in the high frequencies of the regulation earthquakes, frequencies which generally have little impact on the design of buildings and structures, as they are beyond their frequency of interest. ASN considers that these are overshoots for which the implementation of changes and reinforcements enables the margins to be restored (the goal of a reassessment being in particular to define the changes to be implemented for conformity with reassessed requirements). In addition, when the applicable baseline safety requirement is not yet the RFS 2001-01, EDF has already carried out studies in preparation for the forthcoming ten-yearly outage inspections using this baseline, in order to define and implement the necessary reinforcements or changes. The DBE margins for the nuclear island and the site structures are not identical, in that the site structures were designed on the basis of earthquakes normalized on local seismic characteristics. The robustness of the civil engineering structures participating in prevention of the loss of the heat sink (in particular the pumping station and networks) or electrical power supplies (in particular the
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