EDF / 2018 Reference document

PRESENTATION OF EDF GROUP Description of the Group's activities

other specific maintenance operations, in particular renovation or replacement of ■ major components. At the end of the ten-year inspection, the ASN decides whether to approve the restart of the reactor and then issues technical prescriptions setting the conditions for continuing operation. Operation of EDF’s nuclear fleet Nuclear generation resources, owing to their low variable cost are first used for base-load generation, immediately after run-of-river hydropower and other unavoidable renewable energies, as well as the energy purchased under buying obligations from decentralised energy producers. Variations in energy consumption over one year (summer-winter, day-night) and the currently restricted fluidity of wholesale markets due to limited interconnections on the borders lead nuclear energy to be used also for mid-merit generation. High variations in seasonal consumption in France and its major variation during winter months require that planned nuclear fleet outages be concentrated between April and October. The 2003 heat wave highlighted the consequences of very strong warming of rivers, especially on the conditions for operating “riverside” units. The scheduling of unit outages was therefore reviewed to reduce the number of outages of “seaside” units in July and August to encourage these units to continue operating as much as possible since cooling capacities are less dependent on weather conditions. Generation and technical performance The nuclear fleet produced 393.2TWh in 2018, up 14.1TWh compared to that of 2017. Nuclear generation expressed in annual energy corresponds to a load factor rate referred to as “Kp” for the French nuclear fleet (defined as the ratio of energy generated to the maximum theoretical energy, or the energy generated if the installed capacity were operated year-round). This rate is obtained by multiplying two coefficients (Kp = Kd × Ku): the availability factor (“Kd”) (the available energy (3) as a percentage of the ■ theoretical maximum energy, or the energy generated if the installed capacity were operated year-round). The Kd depends on outage durations, and is therefore impacted by standard durations and the work programme to be performed; a utilisation factor, “Ku” (energy generated compared to energy available). The ■ Ku factor reflects environmental, regulatory and social constraints, supply of system services and optimisation implemented by EDF (fuel and modulation). In 2018, the Kp factor reached 71.1%, on a slight increase compared with that of 2017 (68.55%). This results from a Kd of 76.5%, lower than in 2017 (77.1%) and a Ku of 92.8%, higher than in 2017 (88.92%). In 2018, generation performance was affected by exceptional damages and large generation incidents (costing around 12.5TWh), longer-than-expected outages (costing around 5TWh) and environmental constraints (costing around 2TWh). The outage extensions experienced in 2018 were caused in equal measure by maintenance and operational quality issues, technical failures and project management deficiencies. Performance losses related to unplanned outages rose from a rate of 3.26% in 2017 to 3.7% in 2018 because of several exceptional incidents. Without these, the rate of unplanned outages would have been 3%. These figures do not undermine the maintenance strategy implemented in 2007 to renovate and replace major components which has brought the overall rate of unplanned outages down to 30% since 2009. The main technical incidents that impacted generation in 2018 are: continuing and finalising activities to restart the Paluel 2 reactor after the fall in ■ late March 2016 of a worn-out steam generator in the Paluel 2 reactor building, when it was being replaced during the reactor’s third ten-year inspection. The primary coolant system passed the hydropower test performed on 20 April 2018 and the ASN (French Nuclear safety authority) officially authorised the criticality of the Paluel No. 2 reactor on 13 July 2018. Paluel 2 was returned to the network on 23 July 2018;

The purpose of these generation allocation contracts is to make available to each partner the proportion of energy generated actually due to him, based on the share of the capacity allocated to him – in return for payment of their share of the construction costs, annual operating costs (including upstream and downstream fuel costs), local taxes and taxes specific to nuclear energy, and the costs relating to decommissioning. In these transactions, the partners have shared with EDF the industrial risks in the development of the fleet and assume the risks linked to performance concerning the current operation of the power plants. On the other hand, they have no operational role. Furthermore, EDF signed a second type of generation allocation contract relating to a pool of power plants (totalling approximately 2GW) under which EDF makes available to its partners a share of the electricity determined by the level of availability of all or part of a standard fleet, applied to the capacity share reserved to the partners for the units concerned. These contracts mainly concern the following power plants: Chooz B1-B2 (N4 initial series unit): Electrabel (21.7%); ■ Cattenom 3-4: Électricité de Laufenbourg (7.8%) and CNP (21.8%). ■ Operation and technical performance 1.4.1.1.2 of the nuclear fleet Nuclear power is a means of generation whose variable cost, mainly fuel-related costs, is low since it represents les than 30% of operating costs (1) . The main competitive levers of the nuclear fleet in its operating phase are thus the amount of generated energy and the optimisation of fixed operating and maintenance costs. The levers relating to the fuel cycle are further discussed in section 1.4.1.1.4 “The nuclear fuel cycle and related issues”. To reconcile the challenges linked to the strong variations in seasonal consumption in France, due to its strong temperature sensitivity, the availability of maintenance resources and the efficient use of reactor fuel, EDF has now adopted generation cycles of 12 and 18 months for its fleet. At the end of 2018, this breakdown was as follows: 28 units of the 900MW series have an operating cycle of approximately ■ 12 months; 6 units of the 900MW series, 20 units of the 1,300MW series and 4 units of the ■ N4 (1,450MW) series have an operating cycle of approximately 18 months. At the end of these operating cycles, shutdown periods are programmed in order to replace a fraction of the fuel loaded in the core and perform maintenance work. Two types of planned outages are alternated at the end of each generation cycle: an ordinary shutdown for refuelling, for a standard period of approximately ■ 35 days, during which unloading spent fuel and reloading new fuel is the main operation performed; although light maintenance or periodic testing may also take place during this type of outage; a partial inspection for refuelling and maintenance for which the standard ■ period (2) lasts approximately 70 days. Every ten years, the power plant is shut down for a standard period of approximately 110 days in order to carry out a ten-year inspection. This length of time varies according to the works and maintenance programme, as well as the series concerned. The programme for a ten-year inspection includes the following: unloading of spent fuel and reloading of fresh fuel, as at each outage; ■ hydropower tests of the primary coolant system, a leak test of the containment, ■ and inspection work of the reactor’s pressure vessel; modification work, associated with ten-year safety re-evaluations; ■ peration methods of the nuclear fleet Generation cycle and planned outages

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Operating costs are defined as follows: fuel costs (including downstream expenses in the fuel cycle), operating expenses (purchases and external services, employee expenses) and (1) maintenance costs (expenses and investments). They do not include investments related to construction or decommissioning expenses. Standard durations represent optimised and realistic reference durations by outage types. They take into account the feedback from past outages. Outage planned durations (2) fluctuate around these standard durations, depending on the work programme to be performed. Available energy is equal to the maximum theoretical energy less generation losses due to technical reasons inherent to power plants, such as planned outages, unplanned (3) outages due to failure or safety requirements, and performance of regulatory tests.

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EDF I Reference Document 2018