ASN Report 2018

NOTABLE EVENTS 2018 A review with major implications The 34 EDF reactors with a power of 900 MWe were commissioned between 1977 and 1987 and the first ones are approaching their fourth periodic safety review. This is the context in which the conditions for the continued operation of these reactors will be defined. This fourth periodic safety review comprises particular challenges: •  Some equipment is reaching its design lifetime. The studies concerning the conformity of the installations and the management of equipment ageing therefore need to be reviewed to take account of the degradation mechanisms actually observed and the maintenance and replacement strategies adopted by EDF. •  The modifications associated with this periodic safety review will enable the integration of the modifications specified by ASN following the Fukushima Daiichi NPP accident to be completed on these reactors. •  The safety reassessment of these reactors and the resulting improvements must be carried out in the light of the new generation of reactors, such as the EPR, the design of which meets significantly reinforced safety requirements. At the end of 2020, ASN will issue a position statement on the EDF generic studies applicable to all reactors In 2013, EDF sent ASN its objectives for this periodic safety review, in other words, the level of safety to be achieved for continued operation of the reactors. After examining the objectives proposed by EDF, with the support of IRSN, and following consultation of its Advisory Committees, ASN released a position statement on these objectives and issued additional requests in April 2016. EDF supplemented its programme of work and in 2018 presented ASN with the measures it envisages taking in response to these requests. With the support of IRSN, ASN is continuing to examine the generic studies linked to this review. In 2018, ASN more particularly obtained the opinion of its Advisory Committees on the management of ageing and obsolescence and on the mechanical strength of the reactor pressure vessels. It will again ask them for their opinion in 2019 and 2020 regarding: •  nuclear pressure equipment, more particularly the thermomechanical loads stressing the vessels; •  the accident studies in the safety case; •  the ability of the installations to withstand internal and external hazards; •  the probabilistic safety analyses; •  the management of accidents with core melt. In September 2018, ASN sent EDF its initial observations on the inspections and modifications EDF intends to implement on its reactors in order to meet the objectives of the periodic safety review. ASN will issue a position statement on the generic studies for this periodic safety review at the end of 2020. 2017 2016 2013 GENERIC GUIDANCE GENERIC ASN position statement on the review objectives, further to the opinion of the IRSN and the Advisory Committees and to the public consultation EDF generic guidance file Proposed review objectives and programme Partial conclusions of the generic EDF studies GENERIC PHASE OF THE 40-YEAR Nuclear power plants Fourth periodic safety review of the 900 MWe nuclear reactors I n the same way as any BNI, the nuclear reactors undergo an in-depth periodic safety review every 10 years, in order to check their level of safety and make any necessary improvements. 16  ASN report on the state of nuclear safety and radiation protection in France in 2018