At Fessenheim, the two pressurised water reactors were shut down definitively on 22 February 2020 and 30 June 2020 respectively, in accordance with the law and before the end of their technical operating life. The Consolidated Preliminary Plan (avant-projet consolidé or APC) was finalised in late 2018, with more in-depth studies and derisking of the Summary Preliminary Plan (avant-projet sommaire or APS). The dismantling plan was sent to the ASN in September 2019 together with the declaration of the permanent shutdown of this INB. The studies conducted in 2019 and 2020 focused on preparing the dismantling plan, which was sent to the ASN on 2 December 2020. After the filing date, the ASN will examine the documents for a period of 3 to 5 years. 2021 was marked by the complete defueling of reactor 1, preparations for decontamination of the primary circuit which will take place in 2022, dispatch of the first operating waste to the ICEDA facility, and dispatch of the uppermost parts of the steam generators to the subsidiary Cyclife Sweden for processing, in line with the objectives of the work and studies done in preparation for decommissioning of Fessenheim.
The decommissioning provisions cover future decommissioning expenses as described above (excluding the cost of removing and storing waste, which is covered by the provisions for long-term radioactive waste management).
Details of changes in decommissioning provisions for nuclear power plants are as follows:
| Increases |
Decreases |
31/12/2021 | |||||
|---|---|---|---|---|---|---|---|
| (in millions of euros) | 31/12/2020 | Operating | Financial (1) | Utilisations | Reversals | Other changes (2) | |
| Provisions for decommissioning nuclear plants in operation | 12,775 | - | 396 | (7) | - | (484) | 12,680 |
| Provisions for decommissioning permanently shut-down nuclear plants | 4,714 | 262 | 253 | (179) | - | - | 5,050 |
| TOTAL DECOMMISSIONING PROVISIONS FOR NUCLEAR POWER PLANTS | 17,489 | 262 | 649 | (186) | - | (484) | 17,730 |
(1) Cost of unwinding the discount and effects of changes in the net discount rate for provisions without related assets.
(2) Other changes in provisions for decommissioning nuclear plants in operation notably include the impact of the extension to 50 years of the depreciation period for 1,300MW-series plants (see note 2.1.1), partly counterbalanced by the effects of the change in real discount rate at 31 December 2021.
Until 2013, provisions were estimated based on a 1991 study by the French Ministry of Trade and Industry, which set an estimated benchmark cost for decommissioning expressed in €/MW, confirming the assumptions defined in 1979 by the PEON Commission. These estimates had been confirmed from 2009 by a detailed study of decommissioning costs conducted by EDF at the representative site of Dampierre (four 900MW units), and its results were corroborated by an intercomparison with the study carried out by consultants La Guardia, based mainly on the Maine Yankee reactor in the US.
In 2014 the Dampierre study was reviewed by EDF to make sure that the previous calculations were still valid in view of recent developments and experience, both internationally and internally. For this revision, the decommissioning provisions for plants in operation were based on costs resulting from the Dampierre study, in order to incorporate best estimates and experience from inside and outside France. This change of estimate had no significant impact on the level of provisions at 31 December 2014.
Between June 2014 and July 2015, an audit of dismantling costs for EDF’s nuclear fleet currently in operation was conducted by specialised consulting firms, at the request of the French Department for Energy and Climate (Direction générale de l’énergie et du climat or DGEC). On 15 January 2016 the DGEC published a summary of the audit report. It stated that although estimating the cost of decommissioning nuclear reactors is a demanding exercise due to relatively limited past experience, the prospects of changes in techniques, and the distant timing of the expenditure, overall, the audit confirmed EDF’s estimate of decommissioning costs for its nuclear fleet currently in operation. The DGEC also made a number of recommendations to EDF following this audit.
In 2016, EDF revised the decommissioning estimate, in order to incorporate the audit recommendations and past experience gained from dismantling operations for first-generation reactors (particularly Chooz A).
A detailed analytical approach was used to revise this estimate, identifying all costs for the engineering, construction work, operation and waste processing involved in future decommissioning of reactors currently in operation. This led to figures based on detailed timetables for plant decommissioning. The approach adopted made it possible to explore more thoroughly the assessment of costs specific to the initial units of each series, estimated for each series based on transposition coefficients applied to the baseline costs for the initial 900MW unit, and the series and mutualisation effects, as these costs and effects are inherent to the fleet’s size and configuration.
The natures of the principal series and mutualisation effects used to arrive at the estimate are explained below.
Series effects (effects of work for the first-of-a-kind site on the following sites of the same series) are mainly of two types:
Mutualisation effects (effects between units in the same site, whether in operation or being decommissioned) are of several different types:
Due to mutualisation effects, dismantling a pair of reactors on the same site costs less than dismantling two standalone reactors on two different sites. In France, unlike other countries, there are no single reactors but sites with two or four, and in one case six reactors.
Series and mutualisation effects reduce the estimated decommissioning cost by 10% and 6% respectively compared to an estimate that ignores these effects. These effects vary depending on the series: they are greater when there are more units in a series (series effect) and more units on a site (mutualisation effect), leading to a combined effect (series and mutualisation effect) of over 16% for the 900MW series.
In particular, series and mutualisation effects explain why it is not appropriate simply to compare the average dismantling cost per reactor between the French fleet and other countries’ nuclear fleets.
In contrast, the estimates only marginally reflect changes in productivity and the learning effect. The external audit of the decommissioning cost for the fleet currently in operation, ordered by the DGEC, considered that this approach resulted in a prudent estimation method.
