Most on-site maintenance activities are entrusted to subcontractors selected on the basis of an assessment and qualification system concerning which the ASN considered no particular comments to be necessary. The ASN observed that in 2004, the supervision of the activities entrusted to the subcontractors needed to be improved. It observed in 2005 that progress had been made on this point, through implementation of a national reference system designed to ensure that supervision was better organised and better implemented by the licensee. The situation does however need to be further improved for those aspects concerning the coordination of this improvement process and its correct implementation by all departments, the quality of the supervision programmes and the effective supervision of activities in the field. The ASN will in 2006 continue its monitoring and assessment of EDF on these points. During field inspections it will check that the action initiated continues, is better coordinated and takes account of acquired experience concerning supervisory methods and human resources.

The ASN considers that the skills and resources dedicated to maintenance are on the whole appropriate. The inspections carried out on the worksites however indicate that the workload imposed on the staff is heavy and that conventional workplace safety requirements are not always complied with.

Equipment condition

The ASN believes that the equipment maintenance and replacement programmes, the safety reviews approach and the questioning attitude consisting in checking the design and conformity of the facilities in order to correct any anomalies, help maintain the plant equipment in an adequate condition.

• First barrier

The ASN is on the whole satisfied with the control of the first containment barrier, in other words the fuel cladding. However, damage or loss of fuel assembly tightness still occurs on most sites despite preventive steps being taken.

• Second barrier

The ASN considers that the second barrier, mainly consisting of the primary system, remains satisfactory: EDF pays particular attention to it and implements stringent maintenance programmes. EDF action concerning the first generation of steam generators - replacement programme underway since the 1990s and targeted maintenance since 2004 - is helping to achieve significant improvements in their integrity. The ASN considers that it is necessary to maintain particular attention on controlling the ageing phenomena affecting the main primary system.

• Third barrier

The condition of the third barrier, that is the reactor containment, is on the whole satisfactory. Feedback from operation of the single-wall containments of the 900 MWe reactors was reviewed in 2005 with the third ten-yearly outages in mind. EDF was asked for additional studies, particularly concerning containment in outage states, definition of third barrier extension and the "auxiliary buildings containment" doctrine.

The additional studies requested will be reviewed as of 2006. EDF also proceeded with its 1300 and 1450 MWe reactor containments tightness reinforcement work, scheduled to continue until 2011.