Identification and categorisation of safety issues for ESNII reactor concepts. Part I: Common phenomena related to materials

International audience; With the aim to develop a joint proposal for a harmonised European methodology for safety assessment of advanced reactors with fast neutron spectrum, SARGEN-IV (Safety Assessment for Reactors of Gen IV) Euratom coordination action project gathered together twenty-two partners' safety experts from twelve EU Member States. The group consisted of eight European Technical Safety Organisations involved in the European Technical Safety Organisation Network (ETSON), European Commission's Joint Research Centre (JRC), system designers, industrial vendors as well as research and development (RandD) organisations. To support the methodology development, key safety features of four fast neutron spectrum reactor concepts considered in Deployment Strategy of the Sustainable Nuclear Energy Technology Platform (SNETP) were reviewed. In particular, outcomes from running European Sustainable Nuclear Industrial Initiative (ESNII) system projects and related Euratom collaborative projects for Sodium-cooled Fast Reactors, Lead-cooled Fast Reactors, Gas-cooled Fast Reactors, and the lead-bismuth eutectic cooled Fast Spectrum Transmutation Experimental Facility were gathered and critically assessed. To allow a consistent build-up of safety architecture for the ESNII reactor concepts, the safety issues were further categorised to identify common phenomena related to materials. Outcomes of the present work also provided guidance for the identification and prioritisation of further RandD needs respective to the identified safety issues. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-NDlicense

Considerations on GEN IV safety goals and how to implement them in future sodium-cooled fast reactors

International audienceFrom a general perspective generation IV (GEN IV) reactors shall excel in safety and, as part of a continuous improvement process, provide safety enhancements. Safety objectives for GEN III reactors are already very ambitious and, therefore, relevant for GEN IV reactors. This notably concerns et61607;Severe accident prevention; et61607;Severe accident mitigation which is considered in the frame of the fourth defense in depth level;et61607;Response to external hazards, including natural hazards of extreme intensity.Concerning GEN IV sodium-cooled fast reactors (SFR), the achievement of these ambitious safety objectives and the reinforcement of the robustness of the safety demonstration, will be ensured et61607;Firstly, by mastering the sensitive points of the SFR such as neutron reactivity potential of the core, chemical reactivity of sodium, in-service inspection of structures under sodium.et61607;Secondly, by taking full benefit in the design of the favorable characteristics of the SFR such as large thermal inertia, large margin to boiling, natural convection capabilities and by providing high diversification and independence between safety systems associated to different levels of defense in depth.The paper presents some of these possible ways of safety improvement for the future SFR

Astrid safety design radiological confinement improvements compared to previous sfrs

International audienc

Astrid safety design progress on prevention of severe accident

International audienc

ASTRID project : Main progress on safety design provisions

International audienceASTRID is the Advanced Sodium Technological Reactor for Industrial Demonstration which is intended to prepare the Generation IV reactor, with improvements in safety and operability. In order to comply with the related specifications, the Astrid project integrates innovative options. In the earlier phase of ASTRID project, a specific safety approach was set and its main guidelines were agreed by the French Nuclear Safety Authority. This safety design guide is currently applied as reference for the choices of the design options. The paper presents: - The main design provisions, to prevent any severe accident, as far as reasonably possible; - The design approach, called “top-down” approach, relating to the radiological “confinement” safety function

Mitigation of severe accidents for SFR and associated event sequence assessment

International audienc

SARGEN-IV Consideration on the possible content of the safety analysis report for innovative ESNII reactors

International audienceIn view of the potential deployment of demonstrators and prototypes associated with the European Sustainable Nuclear Industrial Initiative (ESNII), the present licensing framework, based on the current Light Water Reactor (LWR) technology, will have to adjust as necessary taking into account to the new safety aspects introduced by these innovative technologies. Within the SARGEN-IV project under the Euratom Framework Programme FP7, an extensive work has been done to review the critical safety features of the reactor concepts developed under ESNII. This review has also been used as a reference to provide guidelines on the structure and content of the Safety Analysis Report (SAR) for the innovative ESNII reactors. Structure and content of a SAR generally differ among countries. The approach followed to give recommendations and guidance was to adopt as far as possible the format of the current practices for LWR based on the US NRC Reg Guide 1.70 together with IAEA publication GS-G-4.1 and to identify those chapters whose subjects need to be adapted to the specific design. Due to the innovative nature of the design, the licensing process for new ESNII concepts may take longer. The early involvement of regulators in defining safety objectives and criteria and acceptable solutions to meet these criteria may be beneficial to shorten this process. Therefore, it is recommended that parts of the SAR should be submitted to the regulatory body at an early stage and in accordance with an agreed timetable; this approach will permit a smoother review process and help preventing unnecessary delays. © 2016 The Authors. Published by Elsevier B.V