- 56 - The older facilities were not designed in compliance with these frame of reference. At Eurodif for instance, the ability of the U annex to withstand the SSE is not demonstrated and measures are in place to limit the quantities of uranium present in this annex. The inspections revealed no breach of these restrictions. For Socatri, the strength of the URS building still needs to be demonstrated on the occasion of the ongoing periodic safety review. For W, operated by AREVA NC, the hydrofluoric acid store would not withstand a SSE and there are uncertainties regarding the SSE resistance of the "ovens" zones. With regard to Comurhex I, neither the BNI nor the SEVESO class chemical facilities are built to SSE design standards. From an organisational viewpoint, there is no overall approach to seismic resistance on the site, with the facilities being organised independently, each under the responsibility of a different licensee. However, there are links between the GBII and Eurodif emergency organisations and Eurodif staff can take part in the emergency crews of the Société denrichissement du Tricastin (SET) or Socatri. The licensees have local initial response teams (ELPI) but the site FLS also responds to all events. The inspections revealed no major discrepancy with regard to the intended earthquake management resources stipulated in the safety report and in the general operating rules. In the facilities, the equipment identified as EIS (element important for safety) in a seismic situation is designed for this risk: maintained function, integrity, stability, absence of potential hazard, as applicable. However, the list of EIS in the case of an earthquake is limited: for example, in the GB II plant, the list of EIS depends on the situation of the facility and there are for example "backup" diesel generators, but which are not EIS, with no "safety" function and not designed to seismic standards (the diesels and their fuel reserves). In the GBII facility, the devices that are "active" in the event of an earthquake (emergency drainage for example) are designed to protect the "investment" rather than being required on safety grounds. However, in the event of an emergency further to an earthquake (UF6 leak, criticality accident, etc.), the licensees of the Tricastin platform can find themselves in a delicate situation: some facilities have no specific instructions concerning how to react in the event of an earthquake (Comurhex for example); most of the facilities have no seismic qualified backup electrical power supplies, because this is not required by the safety frame of reference. Some equipment has a battery or UPS (uninterruptible power supply) backup electrical power supply, but this can be limited to only 30 minutes; the means of communication and monitoring in the facilities are backed up by batteries, for a time ranging from only 30 mn to a few hours (also not designed to seismic standards); on most of the facilities, the crisis centres, the electrical power supply to the control room, the backup electrical generators and the communication networks are not designed to seismic standards; the availability of the fire detection and firefighting resources cannot be guaranteed (power supply to detectors, networks, water); the availability of the resources of the FLS and its ability to intervene on several licensees at Tricastin simultaneously following an earthquake remains to be proven. No water, food, nor stable iodine is stored in the individual facilities, as this has all been grouped for the site as a whole. The food stocks present in the canteens are not protected from any contamination. Finally, the inspectors observed that the availability of the facility or release monitoring resources could not be guaranteed in the event of an earthquake, because this is not generally required in the applicable safety frames of reference. At Eurodif, the licensee found anomalies with tightening of the diffuser anchors in the slab supporting them. The licensee also found an anomaly on the U annex store area: on a 48Y type container of UF6 undergoing cooling, the cover protecting the drain valve against shocks was not locked. This device is not however designed to withstand an earthquake. This anomaly was also observed on other covers and was analysed as a significant safety-related event, with corrective measures.
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