Abstracts ASN Report 2019

ASN ASSESSMENTS PER LICENSEE EDF Áǝƺ zɖƬǼƺƏȸ ¨Ȓɯƺȸ ¨ǼƏȇɎɀ ٢z¨¨ɀ٣ ǣȇ ȒȵƺȸƏɎǣȒȇ ASN considers that the operating rigour of the EDF NPPs regressed in 2019. The number of significant events rated level 1 on the International Nuclear and Radiological Event Scale (INES) has been increasing steadily for several years. It has increased by more than 30% since 2017. Three significant events were rated level 2 in 2019. Two of them reveal inappropriate actions and decisions on the part of the operators and the crossing of organisational defence lines. Furthermore, as in the previous years, the verification procedures undertaken by EDF regularly reveal deficiencies in the design, installation or maintenance of equipment, calling into question their ability to fulfil their functions in all the situations considered in the nuclear safety case. These deficiencies often concern several reactors, given the similarities in the design and operation of the EDF NPPs. The situation scenarios the EDF teams have to address during the ASN inspections show that the operational documentation is not always adapted to the reality on the ground and can contain errors, inaccuracies, and even instructions that are impossible to carry out. Analysis of the significant events moreover reveals situations in which groups of people eventually cease to be aware of the safety implications of their actions, sometimes even becoming used to non-compliant situations. ASN considers that EDF must give fresh meaning to the activities in order to federate the operators around the real safety issues. Improvements in fire risk prevention were nevertheless observed. ASN also notes that EDF places greater importance on the conformity of its installations, which is essential for nuclear safety. Continued operation of the reactors The far-reaching modifications EDF plans making to the facilities and the methods of operational management within the framework of the reactor periodic safety reviews will significantly improve the safety of the facilities. EDF is deploying considerable engineering resources for these reviews. ASN notes however that these national engineering teams have reached the maximum of their capacity. In 2019, EDF performed the first of its 4th ten-yearly outages on one of the reactors at the Tricastin NPP. EDF deployed significant resources for this ten-yearly outage which went reasonably satisfactorily. ASN wonders whether EDF has the capacity to deploy such resources in the future for the other reactors, particularly when several 4th ten-yearly outages take place concurrently. The conformity of the facilities As in 2018, ASN noted that, in comparison with previous years, EDF placed greater emphasis on rapidly restoring the conformity of its facility after detecting a deviation, which is satisfactory. However, as in previous years, ASN considers that the actual conformity of the facilities with the rules applicable to them needs to be significantly improved. The year 2019 was again characterised by the detection of deviations affecting equipment that call into question their ability to fulfil their function in an accident situation. Some of these deviations date back to the construction of the reactors, others have been created when implementing modifications to the facilities, including recently, or result from ageing or insufficient maintenance of the facilities. In 2019, a number of pumping stations were found to be in sub-standard condition and, once again, deviations affecting the emergency diesel generator sets were discovered. Several deviations were also linked to the manufacture of components of items important to safety. This was the case in particular with defective electrical components, which led to a significant event rated level 2 on the INES scale affecting reactor 2 of the Penly NPP. EDF must continue the targeted inspection actions it has been gradually deploying over the last few years, but must also widen their scope. ASN notes that the necessary spare parts are not always available in sufficient quantities. In these situations, ASN is particularly attentive to the effectiveness, the efficiency and the durability of the compensatory measures implemented by EDF pending correction of the anomaly. ASN 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. ASN ASSESSMENTS 8 ASN Report on the state of nuclear safety and radiation protection in France in 2019