ASN Report 2017

418 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 15  - Decommissioning of Basic Nuclear Installations With regard to EDF, the stress test reports for the BNIs undergoing decommissioning (Bugey 1, Chinon A1, A2 and A3, Saint-Laurent-des-Eaux A1 and A2, Chooz A, Superphénix, Brennilis) and the Fuel Evacuation Facility (APEC) (Creys-Malville) were submitted on 15th September 2012. ASN gave its conclusions on 10th October 2014. It considered that the procedure followed complied with the specifications and asked for further information relative to the seismic risk in the APEC and the Gas-Cooled Reactors (GCRs), and the flood risk in the GCRs. The first answers from EDF were examined in 2016, while those still to be received will be examined as part of the periodic safety reviews of the GCR installations. With regard to the CEA installations, the Plutonium Technology Facility (ATPu) (Cadarache) currently undergoing decommissioning was the subject of the ASN resolution 2012-DC-0296 of 26th June 2012 setting out additional requirements in the light of the conclusions of the stress tests. In addition to the generic requirements, ASN asked CEA to keep up to date the estimated quantities of fissile materials present in each area within the ATPu. The quantities of material have greatly decreased in the last few years with the decommissioning and material removal operations. ASN resolution 2012-DC-0293 of 26th June 2012, issued subsequent to the transmission on 15th September 2011 of the stress tests report for the Phénix reactor (Marcoule), sets out additional requirements which aim to reinforce the robustness of the installation against extreme situations, notably by establishing a “hardened safety core”. ASN resolution 2015-DC-0480 of 8th January 2015 also sets additional stipulations specifying the requirements applicable to the “hardened safety core” of the Phénix reactor and the management of emergency situations. In 2017, ASN examined the licensee’s study of the flood risk in the event of beyond design-basis rainfall, which should be supplemented in 2018, and authorised the licensee to put in place information transfer from the NPP to the emergency centre of the Marcoule site. ASN has not issued requirements for the Rapsodie reactor (Cadarache), for which the stress test report was issued on 13th September 2012. Nevertheless, at the request of ASN, the CEA has studied the scenario of a sodium-water reaction induced by rainfall occurring after an extreme earthquake causing devastation of the BNI buildings. ASN considered there was no need to establish additional requirements if the sodium tanks were removed to the Phénix BNI 71 at Marcoule for treatment before the end of 2018. This end-of-removal deadline was stipulated by ASN resolution CODEP-CLG-2017-0222587 adopted on 8th June 2017. The stress test report concerning the Irradiated Materials Facility (AMI) operated by EDF at Chinon was submitted on 6th June 2014. ASN considered on 10th July 2015 that the measures adopted by EDF to mitigate the consequences of an accident situation associated with extreme external hazards, such as those taken into consideration for the stress tests, were satisfactory, provided that the quantity of radioactive substances present in the installation was reduced in the short term. Lastly, with regard to the Areva facilities, after discovering the inadequate earthquake resistance of the Donzére-Montdragon Canal embankment, the systems to mitigate the consequences of a toxic discharge in case of flooding at the Comurhex facility (BNI 105) have been reinforced so that they fulfil their functions in the event of an earthquake (see box in chapter 13, page 381). On the La Hague site, the licensee has put in place provisions to extinguish a fire following an earthquake of the “hardened safety core” design standards in silo 130 and examined their potential deployment in silo 115. ASN will monitor performance of the work to protect silo 115 in 2018. The experience feedback from the Fukushima Daiichi accident for the facilities presenting lower risks will be assessed by ASN later on, more specifically during the next periodic safety reviews of the Procédé and Support BNIs (Fontenay-aux-Roses). The stress tests are not applicable to installations in which decommissioning has reached a stage where such studies would not be justified, or to installations very close to delicensing whose potential source term is very low. 1.6 The international action of ASN in the area of decommissioning ASN participated in various international initiatives relating to decommissioning in 2017. It is involved more specifically in the multilateral work of WENRA (Western European Nuclear Regulators Association), the IAEA and the NEA (Nuclear Energy Agency). ASN takes part in bilateral exchanges between safety Authorities on subjects relating to decommissioning and legacy situations (particularly the retrieval and packaging of legacy waste and polluted sites and soils), the scale of which is growing on the international scene. In 2017, ASN had exchanges more specifically with the NRC (Nuclear Regulatory Commission, United States), the NRA (Nuclear Regulation Authority, Japan) and the ONR (Office for Nuclear Regulation, United Kingdom). A joint visit by ASN-ASND to the main facilities in question (silos, pools) on the Sellafield site in the United Kingdom took place in April 2017, while the ONR visited facilities on the DBNI of Marcoule (spent fuel reprocessing plant UP1, APM pilot unit at Marcoule, etc.) in May 2017, leading to fruitful discussions on the monitoring and verification of the progress of decommissioning projects and on decommissioning preparation work. The three regulators have regular audioconferences on these subjects. A visit to La Hague addressing the same theme is planned in April 2018 2. Situation of nuclear installations undergoing decommissioning Thirty five nuclear installations in France are definitively shut down or undergoing decommissioning. It is planned to shut down some ten more installations in the coming years (see map on following page).