ASN Report 2017

220 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 on the environment; these measures must be continued and maintained over the longer term. Lastly, ASN has also observed an increase in cooling fluid discharges into the atmosphere and significant deviations in control of the explosion risk and lightning protection. In the area of radiation protection, ASN notes that improvements are required in the control of the risk of contamination dispersion, particularly during reactor outage periods. Chinon site ASN considers that the safety and environmental protection performance of the Chinon NPP on the whole is in line with ASN’s general assessment of EDF, and that the radiation protection performance is above the national average. With regard to nuclear safety, the site is maintaining a satisfactory level, as illustrated by the good management of the general operating rules and the temporary safety instructions. Nevertheless, many of the notified significant events are linked to a lack of rigour on the part of the operators and anomalies in the content of the documents used. Reactor outage management can manifestly also be improved, given the numerous findings from the inspections carried out in 2017, particularly concerning management of the risk analyses and of the work tracking documents. The organisation of radiation protection is deemed satisfactory, giving the site good results in dosimetry and radiological cleanness. The risk prevention department is particularly involved in these areas and its field response times are short. Raising the awareness of service providers to radiation protection, and in particular to the rigorous application of the rules for work in radiological environments must however be continued in view of the notified events, albeit few in number. Environmental performance, while comparable with the national average, was down with respect to preceding years. Although gaseous and liquid effluent discharge values remain within limits and few significant events concern the environment, numerous deviations relating to management of the lightning risk and of waste were observed during the inspections in 2017. In June 2017, ASN gave EDF a hearing on its change in decommissioning strategy for the gas-cooled reactors, decided in 2016. This new strategy involves decommissioning the Chinon A2 reactor pressure vessel first, in air rather than under water, before starting decommissioning of the other GCR pressure vessels (see chapter 15). In 2018, ASN will examine the files requested for the examination of this strategy. ASN will also prescribe submission of the decommissioning file for the Chinon A1 and A2 reactors under the Decree of 28th June 2016. Lastly, ASN will examine the periodic safety reviews of the Chinon A1 and Chinon A2 reactors, for which the conclusions reports were received at the end of 2017. ASN considers that the level of safety of the Chinon site nuclear installations undergoing decommissioning (Chinon A1, A2 and A3) is satisfactory in the short term. The inspections carried out in 2017 confirmed the licensee’s involvement in the safety initiative. This being said, waste management – particularly the tracking of interim storage times and waste removal – must be improved. Decommissioning of the Chinon A3 heat exchangers was resumed in August 2017 after developing a new handling system and cleaning out the parts containing asbestos. ASN will be particularly attentive to EDF’s monitoring of the outside contractors who perform the decommissioning operations. With regard to the Chinon A2 reactor, further to the results of the first analyses of the components removed from the reactor systems, additional analyses will be carried out to determine the treatment strategy for this waste. The treatment of chemically polluted soils is in progress. The measures to reinforce groundwater monitoring have been taken and the additional characterisation of the gaseous discharges was finalised in January 2018. The analysis and expert assessment activities of the Irradiated Material Facility (AMI) have stopped and the decommissioning preparation operations are in progress. Since early 2017 the facility has been operated by a new structure that depends on the EDF department in charge of decommissioning. The management of waste treatment operations and the monitoring of equipment in service are satisfactory. Particular attention must however be focused on operating rigour. In a context where the facility’s activities are changing significantly, ASN will be attentive to the management of these changes and compliance with the baseline requirements. The decommissioning authorisation application file was submitted to the environmental authority in the last quarter of 2016 and to a public inquiry in early 2017. ASN is continuing its examination of the decommissioning file. Pending issuing of the decommissioning decree, ASN will be attentive to the progress of the decommissioning preparation operations to reach the initial state planned for when the decree takes effect. In addition, as required by the Decree 2007-1557 of 2nd November 2007 relative to BNIs, EDF transmitted its report on the conclusions of the periodic safety review at the end of 2017. ASN will examine this report and develop its opinion for the Ministry responsible for Nuclear Safety. ASN considers that the operating organisation of the Chinon Inter-regional Fuel Warehouse (MIR) seems robust and ensures efficient monitoring of the commitments made further to the inspections and significant events. Several physical improvements have thus been made in protection against the risks of fire and flooding. The validity of the criteria applied for the inspection of the cranes remains an issue. In November 2017, further additions were made to the periodic safety review file which was initially submitted in 2015 and received its first supplement in June 2016. To compensate for the insufficient earthquake resistance of the handling crane detected in this review, the licensee, as of 2016, put into service two gates to protect the halls against the risk of flooding induced by an earthquake. CENTRE-VAL DE LOIRE