- 60 - The field visits highlighted discrepancies in the equipment contributing to the cooling function in safeguard mode: lack of clamping of a pipe restraint device, absence of a valve tightness plug, lack of an oil reserve on the cooling pumps; deteriorated external condition of certain exchangers; deteriorated (rusted) condition of pumps. A risk of potential damage from stored equipment was identified as being possible on the safeguard cooling lines. To conclude, anomalies were identified on the equipment taking part in cooling (exchangers, fan coil units, piping), with the conclusion being that their maintenance needs to be improved and the continued adequacy of their design over time needs to be checked. Moreover, the continued use of natural ventilation in one of the stores, here the ECC, would seem to be compromised by the anomalies observed during the inspection. Tricastin site None of the facilities inspected during the campaign covered by this report shows any increased safety risk in the event of loss of the heat sink or cooling systems. Only the total loss of the cooling at Eurodif for several tens of hours (the estimate varies depending on the outside temperature) would lead to the UF6 solidifying in the diffusers, entailing probably irreversible clogging of the plant, although with no releases into the environment. Consequently, the licensees have made no provision for any organisation or specific means to prevent this risk. Nuclear fuel fabrication facilities (Mélox, FBFC) For Mélox, the inspectors found that there was tutor-based training in the use of the reflex response sheets. The alarms are transmitted to the control room (security post in the PSG) and to the two safeguard consoles. The inspectors noted that the structures, equipment and functions that need to remain operational were listed. The cooling units are equipped with several control stations. If the chilled water is lost, connection to the industrial water network is possible. The stock of spares is monitored. For the filters, there is a minimum safety stock designed to deal with an earthquake, supplemented by an off-site depot (Pont-Saint-Esprit). No general loss of cooling has been recorded since the creation of Mélox. The annual exercises led the licensee to renovate the safeguard stations. To conclude, the facility is in conformity with its frame of reference. Cooling of the STE stores is safeguarded and, in the event of a loss of the cooling coils - even though they are designed to seismic standards it would be possible to connect industrial water from a fire hydrant or from the Rhone river. The inspectors also noted that Mélox, owing to changes in the materials used and the growth in its production capacity, has had to acquire additional storage capacity (pellets, rods, assemblies) which are equipped with their own cooling system. The inspectors considered that the impact of this new equipment on the safety of the plant should be the subject of an overall assessment. For FBFC, only a few areas of the facilities require cooling, and for no more than a few hours once they are shut down. This mainly concerns the BTU sintering furnaces, owing to their hydrogen risk during operation. These furnaces comprise closed-circuit cooling towers. The inspectors found no anomalies concerning this equipment. 3.4.3 Other facilities ATPu The loss of heat sink was not considered to be pertinent for the ATPu. Only one thermal equipment item is used during operation (the oven in cell C12) but in principle it represents no particular cooling-related safety issues. Masurca For Masurca, the inspectors noted that the licensee considers that in the current configuration, the facility does not require "active" cooling (see part 3.3.1). The licensee thus considers that natural ventilation and
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