Abstracts ASN Report 2019

to reinforce maintenance of the piping liable to lead to internal flooding and to ensure improved management of their ageing. • ³ƺǣɀȅǣƬ ȸǣɀǸɀ łŅĸ ĺĸŁĸŅĴĿĿŌё ŇĻĸ ļŁņŃĸĶŇļłŁ ŃŅłĺŅĴŀŀĸņ ļŀŃĿĸŀĸŁŇĸķ ĵŌ lead it to regularly report significant safety events owing to the lack of seismic resistance of certain equipment. These events are the result of targeted inspections gradually being deployed ĵŌ є Ļĸņĸ ŁłŁіĶłŀŃĿļĴŁĶĸņ ĶĴŁ ĻĴʼnĸ ņĸŅļłňņ ĶłŁņĸńňĸŁĶĸņ in the event of an earthquake and they are thus systematically ĴŁĴĿŌņĸķє łŅ ĸŋĴŀŃĿĸё ļŁ ӅӃӄӌё ŅĸŃłŅŇĸķ Ĵ ņļĺŁļĹļĶĴŁŇ ĸʼnĸŁŇ łĹ ĿĸʼnĸĿ ӅׇłŁ ŇĻĸ ŁŇĸŅŁĴŇļłŁĴĿ ňĶĿĸĴŅ ʼnĸŁŇņ ĶĴĿĸ Ҏ ҏ łŊļŁĺ to the lack of seismic resistance of the piping of the emergency diesel generator sets on several NPPs (see box). Ł ӄӄׇ łʼnĸŀĵĸŅ ӅӃӄӌё ĴŁ ĸĴŅŇĻńňĴľĸ łĶĶňŅŅĸķ ļŁ ŇĻĸ ŀňŁļĶļŃĴĿļŇŌ łĹ ĸ ĸļĿє łĿĿłŊļŁĺ ŇĻļņ ĸĴŅŇĻńňĴľĸё ļŀŃĿĸŀĸŁŇĸķ ŇĻĸ operating procedure required in the event of an earthquake on the Cruas-Meysse NPP. This was because the seismic motion detected on this site reached the level requiring shutdown of the reactors so that checks could be carried out. An inspection programme was then defined and carried out before the reactors were restarted. • «ǣɀǸɀ ǼǣȇǸƺƳ ɎȒ ƺɴɎȸƺȅƺ ɎƺȅȵƺȸƏɎɖȸƺɀ The inspections concerning the risks associated with extreme ŇĸŀŃĸŅĴŇňŅĸņ ņĻłŊ ŇĻĴŇ ѡņ łŅĺĴŁļņĴŇļłŁ ŀňņŇ ĵĸ ļŀŃŅłʼnĸķ on the majority of sites. On several sites, ASN more particularly found a lack of forward planning in preparing the facility for the summer or winter configuration. ňŅļŁĺ ļŇņ ļŁņŃĸĶŇļłŁņ ŅĸŃĸĴŇĸķĿŌ ŁłŇĸņ ŇĻĴŇ ķłĸņ not systematically initiate the required measures if certain temperature thresholds are exceeded. These findings led ASN to issue requests for corrective action. The risk assessments associated with the deployment of countermeasures must also be improved. • nǣǕǝɎȇǣȇǕ ȸǣɀǸɀ The inspections relating to lightning reveal the need on all sites to set up reinforced organisation and oversight to improve the integration of the regulatory requirements associated with the ŀĴŁĴĺĸŀĸŁŇ łĹ ŇĻļņ ĻĴōĴŅķє The lightning risk assessments may be based on information which does not actually reflect the real situation on the facilities. Once again this year, ASN observed a significant delay in the performance of the work identified in the technical studies. The deadlines for performance of the periodic checks on the lightning protection systems by the competent inspection organisations are on the whole not adhered to. These points were the subject łĹ ŅĸńňĸņŇņ ĹłŅ ĶłŅŅĸĶŇļʼnĸ ĴĶŇļłŁє ĻĴņ ķĸĹļŁĸķ Ĵ ŃŅłĺŅĴŀŀĸ of work to improve the situation. א ِ ג ِ ו xȒȇǣɎȒȸǣȇǕ ǔƏƬǣǼǣɎǣƺɀ ƬȒȅȵǼǣƏȇƬƺ ɯǣɎǝ Ɏǝƺ ȸƺȷɖǣȸƺȅƺȇɎɀ Maintaining the conformity of the facilities with their design, construction and operating requirements is a major issue insofar as this conformity is essential for ensuring compliance with the safety case. The processes employed by the licensee, notably during reactor outages, contribute to maintaining the compliance of the facilities with the requirements resulting from this safety case. • «ƺƏƬɎȒȸ ȒɖɎƏǕƺɀ The nuclear power reactors must be periodically shut down for replacement of the fuel depleted during the electricity production cycle. One third or one quarter of the fuel is thus renewed at each outage. These outages allow temporary access to certain parts of the facility which are not accessible during production, although with specific radiation protection precautions. They are thus put to good use for verifying the condition of the equipment by carrying out checks, tests and maintenance, as well as for performing works on the facility. These refuelling outages can be of several types: ҄ Refuelling Outage (ASR) and Maintenance Outage (VP): these outages, which last a few weeks, are devoted to replacing a part of the fuel and to carrying out a verification and maintenance programme, which is more extensive during a VP than during an ASR. ҄ Ten-yearly Inspection (VD): this is an outage involving a programme of in-depth verification and maintenance. This type of outage, which lasts several months and takes place every ten years, enables the licensee to carry out large-scale operations such as the complete inspection and hydraulic testing of the reactor coolant system, hydrotesting of the containment or incorporation of design changes resulting from the periodic safety reviews. These outages are scheduled and prepared by the licensee several months in advance. ASN checks the steps taken by the licensee to ensure the safety of the facility, environmental protection and radiation protection of the workers during the outage, as well as the safety of the reactor for the next production cycle. Ł ŇĻĸ ĿļĺĻŇ łĹ ŇĻĸ ŃŅłʼnļņļłŁņ łĹ ļŇņ ŅĸņłĿňŇļłŁ ӅӃӄӇі іӃӇӇӇׇłĹ ӄӈׇ ňĿŌ ӅӃӄӇׇĶłŁĶĸŅŁļŁĺ ņĻňŇķłŊŁņ ĴŁķ ŅĸņŇĴŅŇņ łĹ ŃŅĸņņňŅļņĸķ water reactors, the monitoring performed by ASN primarily concerns: ҄ during the outage preparation phase, the content of the outage programme drawn up by the licensee. As necessary, ASN may ask for additions to this programme; Áǝƺ ƳƺˡȇƺƳ ȸƺȷɖǣȸƺȅƺȇɎɀ The Order of 7 February 2012 states that a defined requirement is a “ requirement assigned to an Element Important for the Protection (EIP) of persons and the environment, so that it can, with the expected characteristics, perform the function stipulated in the safety case mentioned in the second paragraph of Article n٫ ڳ ׮ ײ ׬ װډ Ȓǔ Ɏǝƺ 0ȇɮǣȸȒȇȅƺȇɎ !ȒƳƺ٦ Ȓȸ ɎȒ Əȇ ƬɎǣɮǣɎɵ Important for the Protection (AIP) of persons and the environment, so that it can meet its objectives with regard to this safety case ”. For the EIP, these requirements can in particular concern: ཛྷ the characteristics of the materials used; ཛྷ the manufacturing, assembly, erection and repair processes; ཛྷ the physical parameters and criteria characteristic of the performance of the EIP. For the AIP, these requirements can in particular concern: ཛྷ the skills needed to perform the activity; ཛྷ any qualifications necessary; ཛྷ checks and hold points; ཛྷ the equipment and hardware needed to enable the activity to be carried out in accordance with the regulatory or even contractual requirements, such as to guarantee compliance with the safety case. 292 ASN Report on the state of nuclear safety and radiation protection in France in 2019 ׏׎ ٲ THE EDF NUCLEAR POWER PLANTS