ASN Report 2017

368 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 12  - EDF Nuclear Power Plants In 2019, Tricastin reactor 1 will be the first 900 MWe reactor to undergo its fourth ten yearly outage inspection. The fourth ten-yearly outage inspections for the 900 MWe reactors will continue until 2030. Ageing management In preparation for the fourth periodic safety review of the 900 MWe nuclear power reactors, EDF intends to continue the ageing management approach applied since the third periodic safety review of these reactors, while reinforcing its equipment refurbishment and replacement projects with the prospect of continued operation up to 60 years. Ageing management, in particular for irreplaceable items whose integrity is vital for safety (such as the reactor pressure vessel – see point 2.2 – and its containment – see point 2.3), and obsolescence management, are essential for maintaining a satisfactory level of safety. In 2013 and then in 2016, ASN considered that the implementation of an organisation able to identify the various equipment degradation modes, the corresponding countermeasures and integration of operating experience feedback comply with the majority of its requirements. Nonetheless, this needs to be supplemented, in particular to: ཛྷ ཛྷ evaluate the need for exceptional maintenance operations; ཛྷ ཛྷ identify the possible vulnerabilities in the industrial processes for replacement of components, including in the case of an unforeseen operational events on the nuclear power reactors, and propose steps to improve the robustness of these processes; ཛྷ ཛྷ provide a robust demonstration of the mechanical resistance of the vessels beyond their fourth ten-yearly outage inspection. ཛྷ ཛྷ take account of environmental effects on the mechanical fatigue phenomenon. This ageing and obsolescence management approach, currently being reviewed with the assistance of IRSN, will again be examined at the beginning of 2018 by the GPR and GPESPN. In addition, the issue of ageing management was the subject of the first Topical Peer Review stipulated by Council Directive 2014/87/EURATOM of 8th July 2014 amending Directive 2009/71/Euratom establishing a Community framework for the nuclear safety of nuclear installations. This Directive requires a peer review, every six years, of a technical aspect relating to the nuclear safety of their nuclear facilities. The procedures of this review are defined by ENSREG (European Nuclear Safety Regulators Group) (see chapter 7, point 1.1) reporting to the European Commission. 1,300 MWe reactors The second periodic safety review In 2006, ASN gave a favourable opinion to the generic aspects of continued operation of the 1,300 MWe reactors up to their third ten-yearly outage inspections, provided that the modifications decided on during this review were effectively implemented. The twenty 1,300 MWe reactors have now all undergone their second ten-yearly outage inspections and have incorporated the improvements identified by the periodic safety review. Pursuant to Article L.593-19 of the Environment Code, ASN in 2014 sent its position statement on the continued operation of the two Saint-Alban reactors, Cattenom reactors 2 and 3, the two Nogent-sur-Seine reactors and Penly reactor 1 and took this opportunity to issue additional requirements designed to reinforce the safety of these nuclear power reactors. It is currently preparing its position regarding the continued operation of the other 1,300 MWe reactors. The third periodic safety review In early 2015, ASN ruled on the generic aspects of the continued operation of the 1,300 MWe reactors beyond thirty years. ASN considers that the steps taken or being envisaged by EDF to assess the condition of its 1,300 MWe reactors and manage their ageing up until the fourth periodic safety review are acceptable. ASN also considers that the modifications identified by EDF during this study phase will help to significantly improve the safety of these installations. These improvements in particular concern reinforcing protection of the facilities against hazards, reducing releases of radioactive substances in the event of an accident, with or without core melt, and preventing the risk of uncovering of the fuel assemblies stored in the spent fuel pit or during handling. Paluel reactor 1 was the first 1,300 MWe reactor to carry out its third ten-yearly outage inspection, in 2016. The Paluel 3, Cattenom 1 and Saint-Alban/Saint-Maurice 1 reactors carried out their third ten-yearly outage inspection in  2016 and 2017. The third ten-yearly outage inspection for the Paluel 2 reactor is in progress. These third ten- yearly outage inspections for the 1,300 MWe reactors will continue until 2024. 1,450 MWe reactors The first periodic safety review The generic studies and modifications associated with the first periodic safety reviews of the 1,450 MWe reactors were the subject of an ASN position statement in 2012, which in particular requested additional work by EDF to demonstrate the adequacy either of the studies carried out, or of the modifications made to the installations during their first ten- yearly outage inspection, in order to comply in full with the objectives set in the periodic safety review. The first ten-yearly outage inspections took place between 2009 and  2012.