EDF takes full regulatory, financial, and technical responsibility for the decommissioning of its plants and the other nuclear installations it operates (including BCOT, St Laurent Silos, and ICEDA). EDF has taken steps to ensure that throughout decommissioning, it controls the entire life cycle of nuclear power generation resources.
Regulatory notice
The decommissioning of a BNF is ordered by a decree, issued after an opinion by the ASN and completion of a public enquiry. This decree determines the characteristics of the decommissioning, the timeframe for its completion, and where applicable, the operations incumbent upon the operator after decommissioning.
The reference scenario adopted by EDF since 2001 is for decommissioning without a waiting period, consistent with French regulations, which provide for decommissioning “in as short a time as possible” after final shutdown on acceptable economic terms and in line with the principles set out in
Article L. 1333-2 of the French Public Health Code and Article L. 110-1 II of the Environment Code (see Article L. 593-25).
The regulatory process for decommissioning involves the following:
The power plants in question that have been permanently shut down are a heavy water reactor (HWR) at Brennilis; a fast-neutron reactor (FNR), Superphenix; the industry’s six natural uranium graphite gas reactors (NUGG) in Bugey, Saint-Laurent, and Chinon, and three pressurised water reactors (PWR): one in Chooz A and those at the Fessenheim site.
The sites remain the property of EDF, and they will remain under its responsibility and monitoring. Given its role as responsible operator, EDF will act as the contracting authority for the decommissioning.
EDF plans a period of 15 years for the decommissioning of Pressurised Water Reactors.
The decommissioning of EDF’s historic nine first-generation units in final shutdown (“first generation” programme) will produce approximately one million tonnes of primary waste materials, of which 80% is standard waste material and none is
High-Level Waste. The remaining 20% comprises Very-Low to Intermediate-Level Waste including about 2% Long-Lived Waste requiring the availability of a storage facility for ILW-LL and LLW-LL. Decommissioning of the two Fessenheim reactors shutdown in 2020 will produce 380,000 tonnes of waste, 95% of which will be
non-radioactive waste.
The existing means of removal of short-lived VLLW and LILW have been supplemented by the Installation de conditionnement et d’entreposage des déchets activés (Conditioning and Storage Facility for Activated Waste, ICEDA) for the conditioning and storage of activated waste from operations and decommissioning (ILW-LL) located on the Bugey site (the commissioning of which was authorised by the ASN on 30 July 2020);
The scheme for handling waste from decommissioning still needs to include the construction of the LLW-LL repository (see the paragraph on LLW-LL in section 1.4.1.1.2.3 “Nuclear fuel cycle and related issues”). Moreover, the new dismantling schedule of the NUGG plants provides for the construction of a storage facility for the LLW-LL liners of the silos at Saint-Laurent, pending the availability of a definitive disposal route (first removal of graphite in 2044).
2020 was impacted by the Covid-19 health crisis, which affected all the decommissioning works in progress; these were stopped for a period of 3-4 months (with varying degrees of impact on the critical path of these projects).
Chooz A: deconstruction of the Chooz A plant is continuing to schedule with cutting and extraction of the internal components of the reactor vessel (following the filling of the reactor pool in 2018). However, the interruption of worksites during the lockdown phase resulted in extensive growth of organic matter, worsening the turbidity of the pool between March and July. This required the implementation of new, more cumbersome treatment solutions, causing a further suspension of internal component cutting operations. The estimated delay for the critical path of the project is between 15 and 18 months.
Chooz A is a pressurised water reactor using a technology similar to the 58 units in operation, but of an older design. This design makes effective treatment of the water in the pool difficult. It was commissioned in 1967 and operated until 1991 (final ending date for power generation). The reactor location, in a rocky cave in a hillside, means that access conditions and entry and exit of materials and effluent management are more difficult than those of the rest of the existing PWR fleet.
Creys Malville: following the filling of the Creys-Malville reactor vessel at the end of 2017, the decommissioning process continued with the remotely operated cutting of the core cover cap, followed in June 2020 by the start of decommissioning of the internal components of the reactor vessel.
Brennilis: pursuant to a 2008 agreement(1) with the CEA, EDF has become fully responsible for the decommissioning of this facility(2). The deconstruction works included in the scope of the Decree authorising partial decommissioning were finalised by end-2020. The safety concrete for the effluent processing station has been demolished, and the spoil removed. Following the final inspections, decommissioning works to allow this zone to be relisted as a conventional zone were undertaken. At the same time, examination of the decommissioning dossier (filed in 2018) with a view to the publication of a full decommissioning decree (allowing decommissioning of the reactor block itself) is ongoing, with a public enquiry planned for the end of 2021.
NUGG: the industrial strategy of the dismantling of the NUGG reactors was thoroughly reviewed at the end of 2015 with the shift from “in-water” dismantling to “in-air” dismantling. This alternative combined with the newly proposed sequencing of operations took into account the results of the 2013-2015 pre-project studies. They show a prolongation of the operations to dismantle the caisson (about 25 years instead of 10 as originally planned), by completely dismantling an initial series unit before dismantling the other 5 units. Updating the industrial decommissioning scenario for first-generation power plants, particularly NUGG plants, led to a € 590 million increase in the provision at 31 December 2015.
The new dismantling strategy was presented to the ASN’s Audit Council in
March 2016. At the ASN’s request, a group of independent experts was commissioned to assess the robustness of the proposed dismantling whose chief features were confirmed.
The NUGG strategy file, the safety option report for the reactors, and the detailed timetable for operations over the 2017-2032 period were sent to the ASN in 2017. These provided supporting grounds for the technical options adopted, in particular the decommissioning sequencing for the six reactors:
This scenario forecasts an initial removal of the graphite from the first NUGG reactor by 2044 and pushes back the need for a disposal route for the other graphite waste by 2070.
(1) With this agreement the CEA has become fully responsible for the decommissioning of Phénix.
(2) French Decree no. 2000-233 of 19 September 2000.
