Universal Registration Document 2022

Introduction

Other risks
  • Furthermore, despite the quality of operations and the changes made by the Group to its nuclear facilities, it cannot be ruled out that some of these facilities will be subject to special operating conditions to reinforce the operating safety margins at the initiative of the nuclear operator responsible for nuclear safety or at the request of the Nuclear Safety Agency.
  • Finally, a potential serious nuclear accident not involving the Group but with widespread consequences worldwide could lead the safety authorities to require new reactor upgrades applicable to the Group’s reactors, and to those in which the Group has a stake.
c) Control actions

The action plans for this risk are carried out by all the operational engineering and operating teams of the nuclear fleet, particularly in the context of the Start 2025 and Grand carénage projects (see section 1.4.1.1.2.1 “EDF’s nuclear plant in France and its operation”).

During the ten-year inspections, the safety assessment makes it possible to increase the level of safety by taking into account, on the one hand, international best practices and, on the other hand, the condition of the facilities, the experience acquired during operation and the developments in the knowledge and rules applicable to similar facilities.

The increase in the number of VD4s completed each year (1 in 2019, 1 in 2020, 4 in 2021 and 5 in 2022) and the increase in the load on the industrial fabric are covered by an approach involving the main suppliers of the plant in operation, in order to have a multi-year vision of the load, and to enable the entire nuclear industry to implement the necessary measures (in terms of resources, contractual terms, standardisation, etc.) so as to secure the success of the industrial programme for the plant in operation.

Since December 2019 the Group has been implementing the Excell plan, which aims to enable the French nuclear industry to return to the highest level of rigour, quality and excellence in order to keep up with major projects and meet the needs of existing nuclear power plants in France and the United Kingdom (see section 1.4.1.1.1 “The excell plan”).

Concerning stress corrosion, out of the 16 reactors most sensitive to this occurrence (reactors of the N4 and P’4-1300 series), 10 were treated in 2022 or are undergoing treatment. EDF initiated a plan for inspections across the nuclear fleet, with the aim of completing them by the beginning of 2025, during scheduled- maintenance and fuel-renewal outages of all the reactors. In the case of the reactors of the P’4-1300 series, EDF adapted its treatment strategy for the series as a whole. This strategy, presented in 2022 to the ASM, is aimed at treating the CSC issue on all the 1300-P’4 reactors by the end of 2023. For these reactors, EDF is contemplating full preventive replacement of the pipes for the safety injection lines of which the welds could be affected by CSC.

At the beginning of 2023, as part of the inspection and assessment program initiated by EDF, a defect was detected on a weld in the safety injection circuit of the Penly 1 reactor, which has the particularity of having been repaired twice during the initial assembly of the circuit during construction. On 10 March 2023, EDF proposed to ASN a change in its stress corrosion control strategy and accelerated the control of the RIS and RRA welds concerned, in order to take account of the elements identified on the repaired weld at Penly 1(1).

The ASN announced to have taken note of this evolution in the strategy and to continue the technical dialogue with EDF. As of 16 March 2023 and on the basis of the control strategy proposed by EDF, the estimate of nuclear generation in France for 2023 remains within the range 300-330 TWh.

See also section 1.4.1.1.2.1 "Handling of stress corrosion detected on the auxiliary circuits of a number of nuclear reactors".

In the United Kingdom, risk control is also based on:

  • ongoing interactions with the regulator on safety cases relating to the life cycle of facilities, assessment by the regulator and licensing requirements;
  • the graphite management and ageing monitoring programme for the AGR fleet, with frequent graphite inspections, in particular at Heysham 2 and Torness;
  • Sizewell B’s long-term operating programme to manage the production of the business case in support of the decision on the investment programme required for extending the operating life;
  • reviews, where necessary, of the life cycle of the AGRs and actions to prepare for fuel retirement in the event of early closure;
  • strategies for preventive monitoring and maintenance of facilities to enable early consideration of problems that could lead to loss of generation.
5B – Control of radioactive waste treatment and decommissioning of nuclear facilities, and ability to meet related commitments

Summary: The provisions set aside by the Group to cover the expenses relating to the decommissioning of nuclear facilities in France and for the treatment, decommissioning and ultimate disposal of radioactive waste, including long-lived waste from spent fuel treatment and decommissioning, may be exposed to technical, cost and planning risks which could make them insufficient. In order to control these risks, EDF has instituted a dedicated organisation to carry out decommissioning and waste management projects covered by these provisions. The 2020-2021 audit by the DGEC on the decommissioning of halted facilities and the ASN inspection in 2021 on the management of projects for decommissioning NUGG reactors, lent strength both to the scenarios examined and to the relevance of the organisation and management for the projects instituted by EDF. However, several exogenous factors remain, with a likely impact on the expenses of decommissioning and long-term waste management, particularly the following: the inflation risk, the uncertainties regarding the tax treatment of the CIGEO waste management project, the tensions on the industrial fabric and skills shortages, etc. These risk factors could unfavourably impact the estimated expenses, requiring upward revision of the related provisions and of the assets dedicated to covering them, with a negative impact on the Group’s cash flow, earnings and prospects. In addition, these operations must address the CSR challenge of waste management and the circular economy.

Criticality: Intermediate

a) Decommissioning of finally shut-down power plants

In France, the law (Environmental Code) requires every basic nuclear plant operator to prudently evaluate the expenses for decommissioning their facilities and the expenses for managing spent fuel and radioactive waste, including expenses of transport away from the site. The law also requires the setting aside of provisions corresponding to these expenses and the exclusive allocation to covering these provisions of the necessary assets also termed “dedicated assets”. This obligation also applies both to installations that have already been halted, where their decommissioning has not been completed and the authority has not pronounced them to be declassified, and to installations currently in operation, in anticipation of their future decommissioning.

Currently, the operations for decommissioning EDF nuclear installations in France (see section 1.4.1.1.2.3 “The issues relating to the nuclear activity”) chiefly concern reactors that were constructed, operated then finally shut down. These operations cover four different reactor technologies: heavy water reactor (Brennilis), sodium-cooled fast-neutron reactor (Superphenix at Creys-Malville), graphite-moderated and gas-cooled reactors (NUGG reactors at Chinon, Saint Laurent and Bugey) and the pressurised water reactors (“PWR”) at Chooz A and Fessenheim.

(1) See EDF’s press release of 16 March 2023 “Clarification on the stress corrosion phenomenon detected on parts of the auxiliary circuits of the main primary circuit of several nuclear reactors”.