ASN Report 2017

420 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 15  - Decommissioning of Basic Nuclear Installations 2.1 EDF nuclear installations 2.1.1 The decommissioning strategy of EDF The first decommissioning strategy for definitively shut down EDF reactors was transmitted in 2001 at the request of ASN. This strategy has been updated regularly, for example, to adjust the decommissioning schedule or incorporate the complementary studies requested by ASN and elements concerning the future decommissioning of the reactor fleet in service. These updates did not call into question either the decommissioning scenarios or the pace of decommissioning. In March 2016, EDF informed ASN of a complete change in strategy for its Gas-Cooled Reactors (GCRs) which pushes back their decommissioning by several decades. With this new strategy, EDF wants to start with complete decommissioning of the Chinon A2 reactor pressure vessel “in air”, without filling it with water as was initially planned for the Bugey 1, Saint-Laurent-des-Eaux A1 and A2 and Chinon A3, then to decommission the other reactors, also “in air”. ASN heard EDF on this strategy in June  2016 and asked that the files justifying this change be submitted to it in order verify that the new strategy meets the regulatory requirements obliging the decommissioning of nuclear installations in the shortest times possible. EDF submitted the requested files to ASN in March and December 2017. ASN will examine these files in 2018, with a view to adopting a position in 2019. ASN also inspected EDF on this subject in December  2017. This inspection shows that the process applied for the “under water” decommissioning of Bugey was rigorous and effectively took into account the questions of nuclear safety and radiation protection. The inspectors found that the decision to change strategy seems to result primarily from project management difficulties (costs, technical aspects, control of project risks). On the other hand, the decommissioning strategy for the other reactors, namely Brennilis, Chooz A and Creys-Malville, has not been significantly modified. 2.1.2 The Brennilis NPP The Brennilis NPP on the Monts d’Arrée site (BNI 162), called EL4-D, is an industrial prototype heavy water moderator nuclear power reactor cooled with carbon dioxide which was definitively shut down in 1985. EDF has been the nuclear operator of this installation since 2000. Partial decommissioning operations were carried out from 1997 to mid-2007 (plugging systems, dismantling certain heavy water and carbon dioxide systems and electromechanical components, demolition of non-nuclear buildings, etc.). The Decree of 27th July 2011 authorised part of the decommissioning operations with the exception of reactor block decommissioning. The Decree of 16th November 2016, issued after consulting ASN, extended the time frame for carrying out the decommissioning operations authorised by the Decree of 27th July 2011, and more specifically: ཛྷ ཛྷ decommissioning of the heat exchangers; ཛྷ ཛྷ clean-out and demolition of the effluent treatment station. These operations are to be completed before 28th July 2018. During 2017, EDF continued firstly the operations to clean and rehabilitate the equipment present in the reactor containment following the September 2015 fire on the heat exchanger decommissioning worksite, and secondly decommissioning of the effluent treatment station. In 2018, the major issues involved are associated with completion of decommissioning of the heat exchangers and the effluent treatment station, including remediation of the soils situated beneath this building, and performance of the periodic safety review, the conclusions of which shall be submitted at the end of 2018. Furthermore, ASN resolution CODEP-CLG-2017 of 21st August 2017 makes it necessary to obtain the prior consent of ASN before taking samples from the Brennilis reactor block. The Decree of 16th November 2016 stipulates that EDF must submit a complete decommissioning file for the installation before 31st July 2018. ASN shall start examining this file in 2018. FOCUS ASN is preparing for the decommissioning of the Pressurised Water Reactors (PWR) and Fessenheim in particular. In 2017, Decree 2017-508 of 8th April 2017 repealing the license to operate the Fessenheim NPP, makes this repeal conditional on commissioning of the Flamanville 3 EPR reactor, insofar as this repeal would be necessary to avoid exceeding the authorised maximum total production capacity for nuclear-generated electricity, set at 63.2 gigawatts by the Energy Code EDF is therefore preparing to definitively shut down the two Fessenheim reactors should the above conditions be satisfied. The final shutdown notification provided for in Article L. 593-26 of the Environment Code has not yet been sent for the Fessenheim reactors. ASN has nevertheless continued discussions with EDF on the in-service reactor decommissioning files, particularly regarding the applicable administrative procedures and the preparatory operations to be carried out before the decommissioning decree is obtained. Coordination between the various ASN and EDF departments is effectively necessary to control the interim period between final shutdown and decommissioning of the reactors, so that their decommissioning can be carried out in the shortest time possible as required by law in Article L. 593-25 of the Environment Code.