The Committee on the Safety of Nuclear Installations (CSNI) is responsible for NEA programmes and activities that support maintaining and advancing the scientific and technical knowledge base of the safety of nuclear installations.
The Committee constitutes a forum for the exchange of technical information and for collaboration between organisations, which can contribute, from their respective backgrounds in research, development and engineering, to its activities. It supports the exchange of information between member countries and safety R&D programmes of various sizes in order to keep all member countries involved in and abreast of developments in technical safety matters.
The Committee reviews the state of knowledge on important topics of nuclear safety science and techniques and of safety assessments, and ensures that operating experience is appropriately accounted for in its activities. It initiates and conducts programmes identified by these reviews and assessments in order to confirm safety, overcome discrepancies, develop improvements and reach consensus on technical issues of common interest. It promotes the co-ordination of work in different member countries that serve to maintain and enhance competence in nuclear safety matters, including the establishment of joint undertakings (e.g. joint research and data projects), and assists in the feedback of the results to participating organisations. The Committee ensures that valuable end-products of the technical reviews and analyses are provided to members in a timely manner, and made publically available when appropriate, to support broader nuclear safety.
The Committee focuses primarily on the safety aspects of existing power reactors, other nuclear installations and new power reactors; it also considers the safety implications of scientific and technical developments of future reactor technologies and designs. Further, the scope for the Committee includes human and organisational research activities and technical developments that affect nuclear safety.
The Committee may sponsor specialist meetings and technical working groups to further its objectives. In implementing its programme the Committee establishes co-operative mechanisms with the Committee on Nuclear Regulatory Activities in order to work with that Committee on matters of common interest, avoiding unnecessary duplications.
The Committee also co-operates with the Committee on Radiation Protection and Public Health, the Radioactive Waste Management Committee, the Committee for Technical and Economic Studies on Nuclear Energy Development and the Fuel Cycle, the Nuclear Science Committee, and other NEA committees and activities on matters of common interest.
The CSNI meets twice per year to discuss nuclear safety and regulatory issues, review the work performed, and decide on the future programme.
This programme of work is carried out mostly by working groups. These working groups meet once or twice per year to discuss progress and to integrate their efforts; they often rely on the work of task groups to complete specific tasks.
Typical "products" are as follows:
On 1 June 2022, the NEA Committee on Nuclear Regulatory Activities (CNRA) and the Committee on the Safety of Nuclear Installations (CSNI) brought together the operational experiences of three guest speakers from the aviation, health and nuclear sectors. The speakers participated in a panel session that discussed lessons learnt from the COVID-19 pandemic. The Effective Nuclear Regulation and Safety Management in a Pandemic brochure highlights the lessons learnt related to ensuring business continuity during a health crisis and long-term risk management, as well as new initiatives to potentially build upon.
The Programme Review Group is established to perform a programme quality review function within the Committee on the Safety of Nuclear Installations (CSNI) and to provide scientific assistance to the decision-making process of the CSNI. The PRG also supports the Bureau in preparing CSNI meetings and in proposing actions concerning the achievement of CSNI objectives.
The NEA Committee on the Safety of Nuclear Installations (CSNI) established a task group to examine Defence in Depth of Electrical Systems and Grid Interaction (DIDELSYS). The DIDELSYS Project, carried out in 2008-2009, made recommendations (see the final report NEA/CSNI/R(2009)10) to strengthen the robustness and defence in depth capabilities of individual NPP onsite electric systems. This was done by systematically evaluating the full range of voltage/frequency transient hazards and planting specific capabilities to cope with these hazards.
The Senior Expert Group on Safety Research / Support Facilities for Existing and Advanced Reactors 2 (SESAR/SFEAR2) is responsible for reviewing and updating the previous SESAR assessments of research facilities required to support the safety of nuclear installations. The group shall recommend actions to be taken by the Committee on the Safety of Nuclear Installations (CSNI) and its member countries to facilitate broader use and sustained operation of essential research facilities required to support nuclear safety.
The Senior Expert Group on Safety Research Opportunities Post-Fukushima (SAREF) was established at the June 2013 CSNI meeting to identify research activities to address safety research knowledge gaps related to the Fukushima Daiichi nuclear accident, which would also support safe and timely decommissioning in Japan.
A Task Group on the Robustness of Electrical Systems of NPPs in Light of the Fukushima Daiichi Accident (ROBELSYS) had been set up to improve the understanding of nuclear power plant electrical system robustness and defence in depth by comparing design practices and plant emergency and operating procedures in member countries; to improve the safety review process of nuclear power plant electrical systems by learning from best practices in member countries; and to promote co-operation among member countries to improve safety.
This task group was set up to carry out a pilot project using the methodology propsed in the final SMAP report published in 2007. In this pilot project, the SMAP methodology was applied to the Zion nuclear power plant in consideration of the US NRC loss-of-coolant accident rulemaking change and a power uprate of 10%.
The Working Group on the Analysis and Management of Accidents (WGAMA) is responsible for activities related to potential accidental situations in nuclear power plants, including the following technical areas: reactor coolant system thermal-hydraulics; design-basis accidents; pre-core melt conditions and progression of accidents and in-vessel phenomena; coolability of over-heated cores; ex-vessel corium interaction with coolant and structures; in-containment combustible gas generation, distribution and potential combustion; physical-chemical behaviour of radioactive species in the primary circuit and the containment; and source term. The activities mainly focus on existing reactors, but also have application for some advanced reactor designs. Priority setting is based on established CSNI criteria and in particular on safety significance and risk and uncertainty considerations.
The main mission of the Working Group on the Safety of Electrical Systems (WGELEC) is to advance the current understanding and address safety issues related to electrical systems of nuclear installations. The activity of the Working Group aims at enhancing the safety performance of nuclear installations and improving the effectiveness of regulatory practices in NEA member countries.
The main mission of the Working Group on External Events (WGEV) is to improve the understanding and treatment of external hazards that would support the continued safety performance of nuclear installations, and improve the effectiveness of regulatory practices in NEA member countries.
The objective of the Working Group on Fuel Cycle Safety (WGFCS) is to advance the understanding of relevant aspects of nuclear fuel cycle safety, including: uranium mining and milling; uranium refining and conversion to uranium hexafluoride; uranium enrichment; fuel fabrication and storage (including MOX fuel); spent fuel storage; spent fuel reprocessing; decommissioning of nuclear facilities; radioactive waste management and disposal options (including for spent fuel) and the research and demonstration facilities that support these activities.
The main mission of the Working Group on Fuel Safety (WGFS) is to advance the current understanding and address cross-cutting issues related to fuel behaviour in accident conditions, including work on associated aspects of thermal-hydraulics, oxidation, chemistry, mechanical behaviour and reactor physics.
The main mission of the Working Group on Human and Organisational Factors (WGHOF) is to improve the understanding and technical basis for treating human and organisational factors within the nuclear industry in order to support the continued safety performance of nuclear installations, and improve the effectiveness of regulatory practices, in NEA member countries.
The main mission of the Working Group on Integrity and Ageing of Components and Structures (WGIAGE) is to advance the current understanding of the relevant aspects related with ensuring the integrity of components, systems and structures (SSC), and to propose general principles on the optimal ways of dealing with respective challenges facing operating and new nuclear power plants as well as other nuclear facilities, and to make use of an integrated approach to design safety and plant life management.
The Working Group supports improved uses of Probabilistic Safety Assessment (PSA) in risk-informed regulation and safety management through the analysis of results and the development of perspectives regarding potentially important risk contributors and associated risk-reduction strategies. The Working Group addresses PSA methods, tools, and data needed to provide this information.