- 33 - organisation is not systematic: some NPPs only have a "heat sink correspondent" who also performs other duties at the same time. The inspectors observed disparities in the monitoring of the heat sink equipment by the sites. In general, those sites where there was no clearly identified person in charge of monitoring the "heat sink" system were less reactive and exhaustive in applying the EDF national requirements. For example, on the Cattenom7 site, where no "heat sink" engineer is appointed, ASN observed a lack of site commitment to preventing heat sink loss risks and a lack of anticipation in the maintenance of certain structures. The recommendations contained in the EDF requirement documents concerning heat sink safety were incompletely adopted and monitoring of the progress of the actions taken was less rigorous than on the other sites. There is also room for improvement in the relations between the NPPs and the EDF head office departments. On numerous occasions, the inspectors found sites waiting for answers or analysis by EDF head office departments, with no real indication of when this would be done. For example, on several sites (including Cattenom and Golfech) the inspectors found deviations from the EDF national frame of reference for the "heat sink" system awaiting processing by the EDF head office departments. Synergy between EDF head office departments and the sites must thus be improved in general. 2.3.3 Conformity of pumping station systems with the EDF national frame of reference (deployment of particular directive DP 143) The 2003 EDF particular directive DP 143 asks the sites to diagnose the conformity of the pumping station systems with the applicable national frame of reference and to take all steps to deal with any anomalies. Exhaustive application by the sites would guarantee the conformity of the NPP pumping stations with the EDF national frame of reference. ASN observed that the steps expected to achieve conformity have been or are in the process of being taken, although anomalies were nonetheless observed at Cattenom NPP. This latter NPP has a list of identified anomalies still in the process of being corrected, but the inspectors were unable to obtain any corresponding deadlines. For its part, the Le Blayais site had problems with integration of the requirements of DP 143. A few sites still need to finalise a number of actions. Overall, ASN observes that EDF is making efforts to bring all the heat sinks into conformity with the national frame of reference and is asking EDF to clear the actions still ongoing. 2.3.4 Integration of experience feedback (REX) particularly interim requirement 303 concerning how to deal with clogging of the heat sink Natural hazards such as the large scale arrival of clogging material (algae, plant debris, fry, silt, etc.) have in recent years had impacts on the heat sinks of several EDF nuclear power plants. EDF was thus asked to learn the lessons from these events and take corrective measures to reduce the vulnerability of its NPPs to the risk of total or partial loss of the heat sink. The inspectors in particular examined application of the internal requirement concerning how to react to clogging of the heat sink (DT 303), as happened to the fleet on two occasions at the end of 2009. In most cases, the inspectors found that operating experience feedback had been satisfactorily integrated by the sites inspected. At least four sites (Bugey, Cattenom, Fessenheim and Golfech among others) have however not yet completed their assimilation of DT 303. For the others, not all the requirements of the directive are applied, which requires further corrective action on the part of EDF. Despite the fact that cooling tower fouling was the cause of a partial heat sink loss in the past, there is no systematic monitoring of this under quality assurance conditions (for example at Saint-Alban). Several sites have mentioned that the internal requirement concerning the collection of data on the heat sink clogging risk (DT 222) for the time being only concerns the coastal sites and that an update to be issued by the EDF head office departments should include the riverside sites by 2012. Examination of local experience feedback showed that the equipment in place was adequate for dealing with heat sink problems, although sometimes not without difficulty. For example, the equipment which retains the plant debris at Golfech was unable to contain the large scale arrival of algae in June 2011. More 7 The Cattenom site is however less susceptible to the risk of loss of heat sink owing to the presence of Mirgenbach Lake which constitutes a cooling water reserve of several weeks in the event of loss of the Moselle river primary heat sink.
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