The Nuclear Safety Authority (ASN) had held a meeting of the GP ESPN on 9 April 2019 as part of its investigation into these quality deviations:
EDF indicated at the time that the recommendations and solution avenues suggested by the Permanent Group of experts could have an impact on the commissioning schedule and construction cost, and that EDF would continue its discussions with the ASN, which was to issue its decision regarding action to be taken on this matter a few weeks later.
Consequently, EDF stated that a detailed update of the schedule and construction cost for the Flamanville EPR would be given after the ASN’s decision had been published.
On 20 June 2019(1), EDF announced that it was aware of the decision issued by the ASN in its letter of 19 June 2019 regarding the quality deviations affecting the welds located on the main steam transfer pipes covered by the break preclusion principle at the Flamanville EPR.
In that letter, the ASN asked EDF to repair the eight containment penetration welds at the Flamanville EPR that were not compliant with the break preclusion principle.
On 26 July 2019(2), EDF announced that three scenarios for upgrading the penetration welds were under consideration, and that after a detailed examination of the three scenarios and discussions with the ASN, EDF would communicate the schedule and cost implications of the selected scenario in the next few months. EDF also stated that commissioning could not be expected before the end of 2022.
This work then resulted in discussions with the ASN, which sent EDF(3) a letter on 4 October 2019 concerning the technical feasibility of these three scenarios.
The penetration weld repair scenario presented as preferred by EDF involves the use of remote-operated robots, designed to conduct high-precision operations inside the piping concerned, a technology developed for nuclear power plants in operation that must be qualified for penetration weld repairs. The aim was to have this scenario qualified and validated by the ASN by the end of 2020, at which date EDF would be able to initiate the repair work. A second scenario involving extraction and realignment work in the Safeguard Auxiliary Buildings was held at this stage as a fall-back solution.
Based on this penetration weld repair strategy, the EDF Board of Directors approved continuation of the Flamanville EPR construction at a meeting hon 8 October 2019.
This led EDF to adjust the schedule and the estimated construction cost for the Flamanville(4) EPR.
The provisional schedule for implementation of the preferred penetration weld repair scenario, if the objective of ASN validation is achieved, sets the date of fuel loading in late 2022 and the revised construction cost at €12.4 billion(5), an increase of €1.5 billion. Most of these additional costs will be treated as operating expenses rather than being capitalised, and will affect the financial years 2020, 2021and 2022.
The main developments at the Flamanville site in 2020 were the following:
The second hot functional test phase started on 21 September 2019 was completed in February 2020. Hot functional testing checks plant performance under simulated normal operating conditions.
In the context of the Covid-19 pandemic, after a cluster of cases was identified in the Manche area, work on the Flamanville site was restricted from mid-March to safety, security and environment monitoring work only (see note 2.1). General activity on the site resumed progressively from 4 May 2020 and was back to near-normal levels in July 2020.
Functional tests of the open reactor vessel were successfully completed between 21 May and 25 June 2020.
In parallel, the upgrading work continued on non-penetration welds on the main secondary circuit that had quality deviations or did not meet the break preclusion requirements defined by EDF, and several welds were repaired in August 2020 once the ASN issued its first authorisations. EDF also decided to include the welds on the circuit supplying water to the steam generators in the scope of the repairs concerning the main secondary circuit. Qualification of the repair procedure for these welds is currently in process, with the objective of performing the work in the second half of 2021. At this stage, the repairs concern a hundred welds in the secondary circuits.
A review was conducted in 2020 of the impact of France’s first national lockdown on the Flamanville project. This did not lead to any change to the fuel loading dates or the construction cost announced in October 2019, but it showed that the project has no remaining margin in its schedule or cost. However, achievement of the targets depends on a number of factors, notably the ASN’s examinations of EDF’s proposed methods for repairing the main secondary circuit welds, particularly the qualification of welding robots for repairing the penetration welds.
Work on these repairs cannot begin until the ASN makes its final decision as to approval of the entire process involving remote-controlled robots, which has been deferred to the first quarter of 2021. This phase of the project is among those in the critical path for on-schedule finalisation of the EPR. A further review of the project will be conducted in 2021.
Since 2014 EDF has been implementing its Grand Carénage programme designed to enhance reactor safety and continue nuclear fleet operations beyond 40 years. The cost of this programme was estimated in 2015 at €55 billion (in 2013 euros) for the period 2014 to 2025. After optimisations and deferrals, this cost was revised in 2018 to €45 million in 2013 euros, i.e. €48.2 billion in current euros, still for the period 2014-2025.
On 29 October 2020, EDF adjusted the programme’s cost for the same period to €49.4 billion in current euros.
The new cost estimate mainly reflects the first findings on the works to be conducted in the context of the ongoing fourth periodic safety review of the Group’s 900MW reactors. This review focuses on studies, modification work and initially unplanned additional equipment to improve safety levels. The estimate also factors in the revised duration of scheduled maintenance outages for ten-year and partial inspections, in response to prior year experience and the impacts of the Covid-19 pandemic for the period 2020-2022 (see note 2.1).
The Grand Carénage programme is continuing with 33 ten-year inspections conducted at the Group’s 900MW, 1,300MW and 1,450MW reactors, and 55 out of 56 emergency diesel generators commissioned.
The ASN’s decision setting the requirements for 900MW reactors in the light of the conclusions of the generic phase of their fourth periodic review is expected by the end of February 2021.
(1) Cf. press release of 20 June 2019.
(2) Cf. press release of 26 July 2019.
(3) Cf. press release of 9 October 2019.
(4) The issue of deviation from the technical manufacturing standards for Framatome reactor components (stress-relieving heat treatment process for the welds with electrical resistance) concerns the four steam generators and pressuriser at Flamanville 3 EPR – see press release of 9 September 2019.
(5) In 2015 Euros, excluding interim interest.
