ASN Report 2017

204 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 08  - Regional overview of nuclear safety and radiation protection to the periodic tests. The year 2017 was marked by the activation of two radiation safety emergency plans within the space of ten days, the first due to a fire which broke out on a section of the roof of the reactor 5 general auxiliary building on19th June 2017: this shows that the Bugey NPP can improve its control of fire-related risks. Noteworthy maintenance work in 2017 included the repair of the reactor 5 containment and the performance of a containment pressure test to requalify the repair. The result is that leakage rates for the Bugey NPP reactor 5 containment are once again in compliance with the general operating rules. The Bugey NPP reactor 5 restarted in July 2017, but EDF will have to demonstrate that the repair remains effective over the long term. With regard to environmental protection, ASN notes that the Bugey NPP adequately controls its discharges. The problem of the containment of liquid substances remains a major issue for the site, as witnessed by the event that led to the detection of tritium in the water table in December 2017. The Bugey NPP also showed a significant improvement in its occupational radiation protection results in 2017. Saint-Alban/Saint-Maurice nuclear power plant ASN considers that the nuclear safety performance of the Saint-Alban/Saint-Maurice NPP is above average for the plants operated by EDF, and that environmental protection and radiation protection performance levels on the whole are in line with the general assessment for EDF. The nuclear safety results for the SaintAlban/Saint-Maurice NPP are satisfactory. In certain areas (compliance with operating technical specifications, configuring the systems), the 2017 results consolidate the progress EDF has made in the last few years. The Saint-Alban/Saint-Maurice NPP does however show below average results in the areas of reactor trips and control of fire-related risks. Concerning maintenance work, the third ten-yearly outage of reactor 1 was an overall success for EDF, particularly with regard to the integration of modifications. Considering environmental protection, the operational results for discharges are satisfactory. The site must nevertheless improve its waste management and the monitoring of the service providers in charge of the premises in which the waste is stored. On the subject of worker protection, the operational results for radiation protection were satisfactory on the whole, particularly during the ten-yearly outage of reactor 1. The work health and safety results are also satisfactory: no serious accident occurred during the ten-yearly outage. Cruas-Meysse nuclear power plant ASN considers that the performance of the Cruas-Meysse NPP with regard to nuclear safety, environmental protection and radiation protection is, on the whole, in line with the general standard of EDF plant performance. With regard to nuclear safety, ASN has noted that the number of deviations notified is down in comparison with the preceding years, reflecting progress which is moreover observed in several areas of activity such as system configuring and reactor control. In 2017, ASN nevertheless found shortcomings in the application of the process to guarantee that certain components which are essential to safety and whose position cannot be seen from the control room are kept in the required position. ASN observes that the maintenance situation at the Cruas- Meysse NPP is still tenuous when the work load increases, particularly during the reactor refuelling and maintenance outages. The reactor 1 outage during which the steam generators were replaced was prolonged due to poor management of the personnel working on certain phases of this job. ASN also notes that the control of fire-related risks is below the standard of the preceding years: the NPP had two fire outbreaks in premises situated in controlled areas. Even though the rapid intervention of the site response teams enabled these fires to be brought under control, it is vital for EDF to improve fire risk prevention. With regard to environmental protection, progress can still be made in waste management, but the site has made improvements in the containment of liquid substances. In terms of radiation protection, the collective dosimetry is still well managed and the radiological cleanliness of the site’s facilities has been significantly improved. Tricastin nuclear power plant ASN considers that the overall nuclear safety performance of the Tricastin NPP is slightly below average for the plants operated by EDF, and that environmental protection and radiation protection performance levels on the whole are in line with the general assessment for EDF. 2017 was marked firstly by the question of carbon segregation zones in the steam generators and secondly by the inadequate earthquake resistance of the embankment protecting the Tricastin NPP against flooding. These two factors led ASN to oblige EDF to carry out specific reactor shutdowns at this facility. Although ASN finds that management of the reactor outage phases was satisfactory in these two situations, it does note that spring and summer were marked by significant events highlighting shortcomings in the monitoring of the facility’s control rooms. These factors led ASN to initiate a tightened inspection on this theme. With regard to maintenance and the initial reactor outage programme, finally only reactors 2 and 3 were shut down for scheduled maintenance and partial refuelling: these two outages went satisfactorily on the whole. With regard to protection of the environment, while the radioactive and chemical discharges are well managed, the Tricastin NPP must further improve its waste management and the containment of liquid radioactive substances. AUVERGNE-RHÔNE-ALPES