EDF_REGISTRATION_DOCUMENT_2017

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 “riverside” 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 379.1TWh in 2017, down 4.8TWh compared to that of 2016. 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 2017 the Kp factor reached 68.55%, little changed from 69.2% in 2016. This results from a Kd of 77.1%, down from 2016 (79.6%) and a Ku of 88.92%, up 1.9 points from 2016 (87%). Generation in 2017 was affected by several significant factors, including: continuing controls to better show that the stream generator potentially affected ■ by the phenomenon of carbon segregation are able to perform their function safely. The analyses and controls performed made it possible to obtain approval from the ASN to restart all of the affected reactors, thus confirming that the reactors are able to operate safely; continuing to investigate quality discrepancies in some of the manufacturing ■ records for forged parts (the records are said to be “crossed” or “uncrossed”) at AREVA NP’s Creusot Forge plant. By end 2017, all roughly 1,600 records had been inspected, of which a little over 1,100 had undergone a technical review. The results of the technical reviews showed that none of the parts in question presented any safety concerns. In the second half of 2017, the analysis summaries for 12 reactors were sent to the ASN which passed the reactors and issued Test Certificates at over 110°C. In early July 2017, a comprehensive analysis of Fessenheim 2 was sent to the ASN with the results of the additional tests carried out in the autumn of 2016 on the steam generator in question which confirmed the integrity of the steam generator and its operational safety. The expert Committee met on 27 February and issued a favourable opinion on returning the Fessenheim 2 steam generator in question to operation. On 12 March 2018, ASN lifted its suspension of the pressure test certificate of a steam generator installed on Fessenheim reactor 2, considering that the anomaly did not compromise its serviceability and that its compliance with the regulations

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 (three series heads are concerned) and assume the risks on performance linked to 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 of 1.4.1.1.2 the nuclear fleet Nuclear power is a means of generation whose variable cost, mainly fuel-related costs, is low since it represents less 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 2017, 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; ■ Operation methods of the nuclear fleet Generation cycle and planned outages

1.

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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DF I Reference Document 2017