Universal Registration Document 2022

Introduction

C – Issues related to decommissioning of nuclear power plants

In its capacity as operator, EDF takes full regulatory, financial, and technical responsibility for the decommissioning of its plants and the other nuclear installations it operates (1).  EDF therefore ensures that it controls the entire life cycle of nuclear power generation resources.

Regulatory notice

Regulations applicable to the decommissioning of nuclear facilities

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 accordance with the legal provisions in force.

The regulatory process for decommissioning involves the following:

  • a final shutdown declaration at least two years before the planned shutdown date, which describes the preparatory decommissioning operations planned;
  • a decommissioning request filed within two years from the final shutdown declaration, which after investigation by the authorities and a public inquiry, will result in a decree ordering the decommissioning of the facility;
  • key progress reviews with the ASN, included in a safety reference system relative to decommissioning;
  • finally, once the work and final shutdown have been completed, the declassification of the facility to remove it from the legal regime governing basic nuclear facilities.

To date, 11 reactors using four different technologies have been permanently shut down:

  • three pressurised water reactors (PWR): one at Chooz A and two at Fessenheim;
  • the heavy water reactor (HWR) at Brennilis;
  • the Superphénix fast neutron reactor (FNR);
  • the six Natural Uranium Graphite Gas (NUGG) reactors at Bugey, Saint-Laurent and Chinon.

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 fifteen years for the decommissioning of Pressurised Water Reactors.

The decommissioning of EDF’s historic nine first-generation reactors in 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% corresponds to ILW or VLLW. 2% of this waste is long-lived and therefore requires the availability of a storage facility for ILW-LL and LLW-LL.

Decommissioning of the two Fessenheim reactors shut down 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 Conditioning and Storage Facility for Activated Waste (ICEDA) for the conditioning and storage of activated waste from operations and decommissioning (ILW-LL) (2).

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 “The issues relating to nuclear activity”). Moreover, the new dismantling schedule of the NUGG plants provides for the construction of a storage facility for the LLW-LL liners (3) 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 the 56 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.

The work begun in 2017 to decommission the Chooz A reactor vessel and its internal components is experiencing difficulties. The health crisis had a serious impact on the work site, in particular due to the halting of filtration resulting in high turbidity levels in the water. The handling crane required to lift the reactor vessel is out of service and the repair works are more complex than anticipated. The work site has also experienced other unexpected issues (slower cutting rates than expected, etc.). The end of the reactor vessel decommissioning work site has therefore been put back to December 2025. There is still a risk of a further deferral of 14 months.

In a separate development, a partnership agreement between EDF and CNRS on a project to reuse the caverns for research on neutrinos once the installations have been decommissioned was entered into on 7 September 2022, in order to make the most of the particular configuration of the facility.

Fessenheim

Reactors 1 and 2 at the power plant were permanently shut down on 22 February 2020 and 30 June 2020 respectively. At the end of 2020, the “PREDEM Fessenheim” project was put into place to coordinate all the end-of-operation procedures (draining of circuits, evacuation of bore, permanent locking-out and removal of certain equipment and support functions, removal of fuel, decontamination of primary circuits, etc.).

All of the spent fuel was removed from the site and sent to La Hague in the space of just over 2 years, a highly satisfactory performance. As a result, 99.9% of the radioactivity has been removed from the site. Work to carry out Full System Decontamination was performed on Reactor 1 in collaboration with Framatome. The same work is also scheduled in the first half of 2023 for Reactor 2, and will allow the best possible working conditions in terms of radioactivity during decommissioning.

The decommissioning dossier was filed with the Minister of Ecological and Solidarity Transition and the ASN in December 2020. Obtaining the decree will mark the start of the decommissioning phase. In early 2022, MSNR (4) and the ASN acknowledged receipt of a fuller version of this dossier (5), marking the resumption of its examination. The current schedule foresees the Decree allowing Fessenheim facility decommissioning to be issued in early 2026. As of the end of 2022, the trajectory for decommissioning preparation activities was in line with the provisional schedule.

In addition, Decree No. 2021-1785 of 24 December 2021 authorised the collection of water from and discharge into the Grand Canal in Alsace for the cooling of various auxiliary circuits at Fessenheim.

 

(1) BCOT (Base chaude opérationnelle du Tricastin), Silos de Saint Laurent, ICEDA…

(2) See “ICEDA” paragraph in section 1.4.1.1.2.3.

(3) 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.

(4) MSNR: French Nuclear Safety and Radiation Protection Mission (Mission de la sûreté nucléaire et de la radioprotection).

(5) Supplied on 23 December 2021 following the MSNR letter dated 4 August 2021.