- 257 - FBFC Romans Design The design of the buildings constituting BNI 98 dates back to the end of the 1970's, and for some of them was based on the PS69 paraseismic rules. During the periodic safety review of BNI 98 carried out in 2003, the characteristics of the maximum historically probable earthquakes (MHPE) and the safety shutdown earthquakes (SSE) to be adopted for the Roman site were validated. These characteristics, obtained by application of RFS 2001-01 and the preceding RFS (RFS I.2.c), which encompass the spectra resulting from strict application of RFS 2001-01, are as follows: MHPE specific to the seismotectonic domain of the site: magnitude = 4.5; depth = 8 km; intensity at the site = VI-VII on the MSK scale; MHPE attached to the associated East seismotectonic domain (including the Vercors region), called "distant MHPE": magnitude = 5.3; focal distance to site = 21 km; near SSE: magnitude =5; focal depth = 8 km; distant SSE: magnitude =5.8; focal distance = 21 km. Measures to protect the facilities with respect to the seismic risk / design-basis earthquakes Further to the 2003 safety review of BNI 9, the two main buildings housing fuel production (buildings C1 and AP2) were reinforced in order to withstand the SSEs validated in 2003. The other structures of BNI 98, apart from the HF station, were not reinforced further to the 2003 periodic safety review. Their resistance to the MHPE and SSE defined in 2003 is not guaranteed. The HF station was put into service in 2005 and designed to withstand the SSEs defined in 2003. Conformity of the facility Conformity of the BNI 98 buildings with the current frame of reference for the facility is not confirmed because the licensee has not verified it exhaustively. The licensee nevertheless specifies the following: the HF station was judged in conformity with its design file when commissioned in 2005 and the reinforcements of building C1 are in conformity with the reinforcements file produced after the safety review of 2003. The next periodic safety review of BNI 98 is to be carried out in 2013. The file to be submitted by the licensee must include an examination of conformity of the entire BNI with the exception of building R1, which is to form the subject of a renovation file that will be submitted at the end of 2012. Assessment of the safety margins The licensee only performed the robustness analysis on the HF station and building C1, and reached the following main conclusions: for the HF station: it can be considered robust to an earthquake of intensity exceeding that of the SSE + 1; for building C1: o Block 4 containing the conversion autoclaves: the resistance of the block was substantiated by an experts' review for an earthquake of magnitude exceeding that of the SSE + 0.5; o Vaporisation unit: margins are reportedly available (not precisely quantified) owing to the margins intrinsic to the design codes used to substantiate the stability of the unit structures. According to the licensee, these margins cover an increase in the seismic loading by a factor of 2; o HF condensation: margins are reportedly available (not precisely quantified) owing to the margins intrinsic to the design codes used to substantiate the stability of the unit equipment. According to the licensee, these margins cover a 4-fold increase in the seismic loading of the structures and a 2fold increase in the seismic loading of the attachments and anchor points.
RkJQdWJsaXNoZXIy NjQ0NzU=