- 26 - states that if the half design response spectrum is exceeded, the reactors are taken to the safest state, jointly with the RTE (electricity transport grid) and the COPM (production contracts operations centre). ASN finds that this step does not meet a safety requirement, does not conform to RFS I.3.b and that the procedures have to be corrected accordingly. Post-seismic diagnostic RFS I.3.b states that "operation may only resume once ASN has been provided with evidence of the harmlessness of the earthquake for the subsequent behaviour of the facility; an analysis of the behaviour of equipment important for safety will be [ ] necessary to obtain authorisation to continue with operation of the units." The inspections revealed that there was no official list of the checks to be performed on the facilities (equipment and buildings) following an earthquake larger than half the operating basis earthquake. Some sites stated that the alarms present in the control room were able to indicate the unavailability of equipment important for safety. These alarms do not give the status of the buildings and equipment not important for safety (IPS) but which enable the reactor to be kept in a safe state over the long term. Other sites indicated that EDF head office departments would be called on in a situation such as this. ASN considers that any crisis situation must be anticipated and that detailed official procedures must be in place so that when the time comes, decisions can be taken in stressful conditions. ASN considers that the diagnosis to be carried out following an earthquake cannot be based simply on the alarms situated in the control room. This diagnosis must be formalised and must take account of the condition of the reactor at the time of the earthquake. Resources available in the event of an earthquake During the inspections, the inspectors observed that the earthquake is managed by the crisis organisation and the material and organisational means defined by the PUI. Following an earthquake, this approach fails to take account of the potential condition of the internal communication routes for access by the emergency services, the vulnerability of fluid networks or the condition of certain buildings in which emergency resources are stored, or of other buildings housing persons designated in the procedures as decision-makers. ASN finds that for all of its sites, EDF needs to identify the general means that would be essential in the event of an earthquake on the site. EDF will check that these means (both on and off the site) are robust to the safe shutdown earthquake as defined in the safety reports. As applicable, other means will be defined in a PUI (radiological or other) and implemented. Training Generally speaking, the inspectors observed that on most of the sites, the operating staff are not made aware of the seismic risk (characteristics and physical manifestations of an earthquake exceeding the alarm trigger threshold or the reactor shutdown threshold). Inclusion of the seismic risk in the training programme The training programme followed by the EDF staff ("Professional Academy") requires familiarity with the requirements of internal directive (DI) n°81 "continued qualification for accident conditions of the equipment installed in PWR units". This DI requires that the approach taken consider the earthquake event 5. New staff also receive tutoring. Finally, awareness-raising campaigns are also conducted (for example at Blayais in 2007, Flamanville since 2010). However, a number of observations made during the field visits showed that the event earthquake approach was not correctly and completely taken into account (for example an overhead crane on the Le Blayais site was not in the parked position). The operational documents do not always mention this point (analysis of risks and inspection programmes for the Chooz construction site for example). 5 Certain functions and equipment require seismic qualification in order to guarantee that they are fully available following an earthquake. Furthermore, the operation of this equipment must not be affected by equipment that is not seismic classified, in particular temporary equipment put in place for maintenance worksites.
RkJQdWJsaXNoZXIy NjQ0NzU=