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 Aand 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 operators, EDF will act as the contracting authority for the decommissioning.
EDF plans for a period of 15 years for the decommissioning of Pressurised Water Reactors.
The decommissioning of EDF’s historic first nine-generation power plants in the final shutdown 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 shut down 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).
The scheme for handling waste from decommissioning still needs to include the construction of the LLW-LL repository (see paragraph on LLW-LL dissection 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(1) of the silos at Saint-Laurent, pending the availability of a definitive disposal route (first removal of graphite in 2044).
Chooz A: Chooz A is a pressurised water reactor using a technology similar to the58 units in operation. It was commissioned in 1967 and operated until 1991. 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.
In 2019, the underwater cutting of the internal components of the vessel(2) was carried out according to schedule. During the health crisis of 2020, the shutdown of the construction site, coupled with operating difficulties due to the lockdowns, resulted in a major turbidity incident in the water(3) of the pool, which strongly impacted the end of the project. The cutting of the vessel’s internal components was completed in late February 2021. The cutting of the vessel will begin in 2023 after the pool has been emptied and cleaned, as well as the cutting of the first components of the primary circuit piping.
Following the letter of interest sent by the CNRS in September 2021, a Memorandum of Understanding (MoU) should be signed with the management of the CNRS in early 2022. It concerns the proposed reuse of caverns for neutrino research in connection with the “SuperChooz” project.
Creys Malville: following the filling of the Creys-Malville reactor vessel at the end of 2017, the decommissioning process continued. In 2020 and 2021, the first two caps were cut (teleoperated procedures) and the cutting of the last cap is in progress. It will then be extracted, thus freeing access to the vessel’s internal equipment for decommissioning (2022-2026).
Brennilis: EDF has become fully responsible for the decommissioning of this facility (4) in place of the CEA. 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 entirely relisted as a conventional zone will be completed in 2022. At the same time, examination of the decommissioning application (5) with a view to the publication of a full decommissioning decree (allowing decommissioning of the reactor block itself) is ongoing: the permanent group on the application filed issued a satisfactory opinion without a recommendation and a public enquiry was begun on 15 November 2021 for a period of 7 weeks. On 17 January 2022, the Brennilis Local Information Commission (CLI) issued a favourable opinion on the proposed application. In addition, the enquiry commission appointed by the Rennes administrative court to conduct the public enquiry also issued a favourable opinion on 2 March 2022.
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 choice, as well as the proposed new sequencing of operations, took into account the results of the pre-project studies conducted between 2013 and 2015. They result in longer decommissioning operations for the reactor caisson (about 25 years instead of the ten years initially planned), requiring the performance of tests in the Graphite Industrial Demonstrator (DIG), and then the complete decommissioning of an initial series unit (Chinon A2) before the complete decommissioning of the other five 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.
This scenario forecasts an initial removal of the graphite from the first NUGG reactor by 2044 and postpones the need for a disposal route for the other graphite waste to 2070.
The ASN rulings published on 3 March 2020 have established a prescriptive framework for the operations and dossiers to be completed within the next 5-7 years on each of the sites. Unlike the aforementioned draught rulings submitted for public consultation, these defer the issue of the schedule for operations until the investigative phase for dossiers relating to decommissioning.
However, in a cover letter accompanying these rulings, the ASN deems that EDF should attempt to shorten the schedule for completing the operations “in view of the statutory obligation to decommission each reactor in as short a time as possible”. EDF confirmed the implementation of a regular review of the schedule based on the results obtained on the industrial demonstrator and the first reactor.
In connection with its subsidiary Graphitech, EDF is already working on avenues for schedule optimisation that should make it possible to include a schedule similar to that of the draught ruling submitted for public consultation in the dossiers filed at the end of 2022 (decommissioning of reactors other than ‘TTS’ lead units from 2055 onwards). Consistently with these works, and in the absence of any further information from tests using the industrial demonstrator and the first real-life operations, there was no change in 2021 to the valuation of the estimated provisions at the end of December 2020.
On 27 December 2021, following an analysis of the periodic review reports on the NUGG reactors submitted by EDF, the ASN indicated in a press release that it had no objection to continuing decommissioning operations or preparations for decommissioning these reactors.
On 20 November 2020, an ASN exploratory procedure designed to verify the maturity of EDF for running complex projects was completed. The Graphite Industrial Demonstrator (DIG) and Chinon A2 projects were inspected by a team comprising members of the ASN, IRSN, and DGEC. The ASN follow-up letter issued on 21 May 2021 confirms the strengths and areas for improvement presented during the hot debriefing. EDF’s response is due within 12 months (May 2022).
(1) The “graphite liners” come from the operation of the former French natural uranium graphite gas (UNGG) reactors. These are hollow cylindrical graphite envelopes that surround the fuel.
(2) The “internal” equipment includes all equipment located inside the reactor vessel, with the exception of the fuel assemblies themselves, the reactivity control clusters and the core instrumentation.
(3) Water clouded by suspended solids.
(4) Decree no. 2000-233 of 19 September 2000.
(5) Filed in 2018.
