ASN Report 2018

AUVERGNE-RHÔNE-ALPES REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION In 2018, ASN noted shortcomings more particularly in the handling of deviations and in environmental protection. ASN therefore considers that EDF must rapidly put in place fundamental measures to restore, in the field, the required technical capacities to maintain the conformity of its installations with the equipment design, manufacturing, production and operating requirements. As regards nuclear safety, ASN notes some improvements with respect to 2017. The Cruas‑Meysse NPP is showing greater compliance with the operating technical specifications, with indicators that having been pointing upwards over the last five years. ASN thus notes a drop in the number of reactor trips and better management of the activities that involve placing system components in a given configuration such that the system and equipment meet operating, availability and safety targets. In late 2017, ASN issued a resolution requiring the Cruas-Meysse NPP to ensure tightened oversight of the operations performed on equipment ensuring the dependability of control of nuclear chain reactions. ASN notes that EDF has taken the subject duly in hand, notably by identifying difficulties in personnel training and shortcomings in the knowledge of certain equipment and in reactor management. A follow-up inspection showed that EDF had put in place a suitable organisation tomeet the requirements of the ASN resolution. However, a significant event reported by EDF in September 2018 shows that EDF must continue its efforts andmaintain its vigilance in this area. The fire risk remains a subject of concern on the site. Despite a reduction in the number of fire outbreaks in 2018, ASN considers it absolutely vital for the NPP to improve its organisation in this respect. Concerning reactor outages, ASN considers that the situation shows a mixed picture; EDF must improve the quality of reactor outage preparation by safeguarding its internal processes. With regard to environmental protection, the summer of 2018 was marked by two cases of water table pollution, one by tritium, the other by hydrocarbons. With regard to radiation protection, 2018 continues in line with the preceding years: collective dosimetry is controlled but there are difficulties in obtaining satisfactory levels of radiological cleanliness during reactor outages and deficiencies in the control of access to areas with high dosimetric risks. Tricastin site The Tricastin nuclear site, situated in the Drôme and Vaucluse départements , is a vast industrial site accommodating the largest concentration of nuclear and chemical facilities in France. It harbours a large number of installations, with a nuclear power plant comprising four 900 MWe reactors, nuclear fuel cycle facilities, and the BCOT (Operational Hot Unit) which fulfils maintenance and storage functions. It is situated on the right bank of the Donzère‑Mondragon Canal (a diversion channel of the river Rhône) between Valence and Avignon. It occupies a surface area of 800 hectares covering three municipalities, namely Saint‑Paul‑Trois‑Châteaux and Pierrelatte in the Drôme département , and Bollène in the Vaucluse département . Tricastin nuclear power plant The Tricastin NPP comprises four 900 MWe pressurised water reactors: reactors 1 and 2 were commissioned in 1980 and constitute BNI 87, while reactors 3 and 4, commissioned in 1981, constitute BNI 88. ASN considers that the overall performance of the Tricastin NPP with regard to nuclear safety and environmental protection is in line with ASN’s general assessment of EDF plant performance. ASN considers that the radiation protection performance, however, is below the national average. In 2016 and 2017, ASN obliged shutdowns of all or part of the facility, due firstly to the question of carbon segregation in the steam generators, and secondly to the deficiency in the earthquake resistance of the embankment protecting the Tricastin NPP against flooding. ASN observes that the management of these outages and the simultaneous restarting of the Tricastin reactors was a real challenge which EDF managed capably on the whole, with no noteworthy significant events. With regard to nuclear safety, although the NPP’s performance was satisfactory until the end of the summer, with areas showing progress (compliance with the operating technical specifications, the configuring of systems, processing alarms in the control room, etc.), ASN nevertheless noted weaknesses in operating quality in the autumn, with the reporting of twelve significant safety- related events in September and October 2018. ASN notes that the Tricastin NPP still has weaknesses in the area of periodic tests. With regard to maintenance, ASN notes that despite the busy industrial programme for 2018, the scheduled refuelling and maintenance outages were capably managed on the whole. 30  ASN report on the state of nuclear safety and radiation protection in France in 2018