ASN Report 2018

ASN ASSESSMENTS PER LICENSEE EDF The Nuclear Power Plants (NPP) in operation ASNconsiders that the safety of EDF’sNPPswasmaintained at a satisfactory level in 2018. However, EDF must make improvementswith regard to certain subjects. This ismore particularly the casewithmanaging the compliance of the facilities with their baseline safety requirements, which needs to be reinforced. On the whole, the number of significant events in 2018 was stable in relation to 2017. No significant event exceeded level 1 on the INES scale. The verifications conducted by EDF regularly bring to light defects which affect several NPPs. Most of these defects are deviations related to the design of equipment, its installation or its maintenance and compromise its ability to perform its function in all the situations considered in the nuclear safety case. The conformity of the facilities As in previous years, ASN considers that the actual conformity of the facilities needs to be appreciably improved. This is more particularly the case with the seismic strength of the equipment. EDF must continue with the targeted inspections it has been gradually implementing for the past few years and which will allow regular detection of the equipment needing to be strengthened. Managing the conformity of the facilities in operation will be a major focus for ASN oversight in 2019, notably on the occasion of the fourth ten-yearly outage inspection of the Tricastin NPP reactor 1. In 2018, EDF began a revision of its internal baseline requirements in order to improve deviations processing and ensure reactive information of ASN: this is a first step forwards. In 2018, ASN also noted that, by comparison with previous years, EDF placed greater emphasis on rapidly restoring the conformity of its facility after detecting a deviation. In order to combat the risk of fraud, EDF has modified its inspection practices, making greater use of unannounced or cross inspections. In 2018, EDF also completed its review of the manufacturing files of the forged components produced by the Creusot Forge plant. The ASN examination of the deviations identified by this review did not reveal any new deviations in 2018 requiring repair or immediate replacement of any equipment item, but it nonetheless issued requests for additional justifications in order to back up the demonstrations provided by EDF. Examination of these additional justifications will continue in 2019. Maintenance EDF has taken steps to reduce the occurrence of maintenance quality defects: their number is however still too high. Some of them could have been avoided by taking greater account of operating experience feedback from other EDF reactors, including on the same site. ASN however finds that most sites have successfully been able to carry out large-scale maintenance operations, such as the preparation for and performance of the ten-yearly outage inspections, which constitute a considerable drain on their human resources, notably those with the most experience, owing to the particularly intense maintenance phases. ASN also considers that proactive measures must be taken by EDF to reinforce its maintenance programmes for certain equipment items. ASN in particular notes very high levels of fouling in certain internal structures of the steam generators in several reactors, which could impair their operating safety. These fouling levels are the result of maintenance that was insufficient to guarantee satisfactory cleanness. ASN considers that the in-service monitoring of the other equipment on the main primary system is carried out appropriately. In 2017, this notably led to the detection of a crack on the vessel bottom head penetration of Cattenom NPP reactor 3, with no change being observed in 2018. ASN ASSESSMENTS PER LICENSEE AND PER FIELD OF ACTIVITY A SN carries out its oversight role by using the regulatory framework and individual resolutions, inspections, and if necessary, enforcement measures, in a way that is complementary and tailored to each situation, to ensure optimal control of the risks that nuclear activities represent for people and the environment. ASN reports on its duties and produces an assessment of the actions of each licensee, in each field of activity. 8  ASN report on the state of nuclear safety and radiation protection in France in 2018