Nuclear Safety Publications
Alphabetical list of titles
Detailed publication list
Implementation of Defence in Depth at Nuclear Power Plants
Lessons Learnt from the Fukushima Daiichi Accident
English, 45 pages, published: 01/28/16
Available online at: http://www.oecd-nea.org/nsd/pubs/2016/7248-did-npp.pdf
Defence in depth (DiD) is a concept that has been used for many years alongside tools to optimise nuclear safety in reactor design, assessment and regulation. The 2011 Fukushima Daiichi nuclear power plant accident provided unique insight into nuclear safety issues and raised questions about the tools used at nuclear power plants, including the effectiveness of the DiD concept, and whether DiD can be enhanced and its implementation improved.
This regulatory guidance booklet examines and provides advice on the implementation of DiD. A key observation is that the use of the DiD concept remains valid after the Fukushima Daiichi accident. Indeed, lessons learnt from the accident, and the accident?s impact on the use of DiD, have reinforced the fundamental importance of DiD in ensuring adequate safety.
This report is intended primarily for nuclear regulatory bodies, although information included herein is expected to be of interest to licensees, nuclear industry organisations and the general public.
The Characteristics of an Effective Nuclear Regulator
English, 32 pages, published: 07/04/14
Available online at: http://www.oecd-nea.org/nsd/pubs/2014/7185-regulator.pdf
Both national and international organisations agree that the fundamental objective of all nuclear safety regulatory bodies -- the regulator's prime purpose -- is to ensure that nuclear licensees operate their facilities at all times in a safe manner. Much has been written about ways to improve regulatory processes or to improve the effectiveness of a regulatory body, including in previous OECD/NEA regulatory guidance booklets. But until now, none have focused on the characteristics of an effective nuclear safety regulator.
Effective organisations are those that have good leadership and are able to transform strategic direction into operational programmes. Effectiveness is about how well the organisation is achieving its fundamental purpose -- in the case of a nuclear safety regulator, ensuring that licensees operate their facilities and discharge their obligations in a safe manner.
This regulatory guidance booklet describes the characteristics of an effective nuclear safety regulator in terms of roles and responsibilities, principles and attributes. Each of the characteristics discussed in this report is a necessary feature of an effective nuclear safety regulator but no one characteristic is sufficient on its own. It is the combination of these characteristics that leads to the effectiveness of a nuclear regulatory body. The report provides a unique resource to countries with existing, mature regulators and can be used for benchmarking as well as training and developing staff. It will also be useful for new entrant countries in the process of developing and maintaining an effective nuclear safety regulator.
CSNI Technical Opinion Papers No. 16
Defence in Depth of Electrical Systems
English, 48 pages, published: 05/17/13
Available online at: http://www.oecd-nea.org/nsd/docs/2013/7070-top-16.pdf
As all safety systems in the majority of existing nuclear power plants use the preferred power supply, any voltage surges in these systems could lead to common-cause failures. In the event of an unusual electrical system transient, it is essential that safety-related equipment be isolated or protected from the fault in order to ensure its ability to safely shut down the reactor and remove decay heat.
Based on the analysis of the voltage surges observed at Forsmark-1 in 2006 and Olkiluoto-1 in 2008, this technical opinion paper summarises the current state of knowledge of in-plant and external grid-related challenges to nuclear power plant safety-related electrical equipment. It will be of particular interest to nuclear safety regulators, nuclear power plant operators and grid system regulators and operators.
Crisis Communication: Facing the Challenges - Proceedings
Workshop Proceedings, Madrid, Spain, 9-10 May 2012
English, 240 pages, published: 05/06/13
Available online at: http://www.oecd-nea.org/nsd/docs/2013/7067-crisis-communication.pdf
As manifested by an increasingly globalised media, a nuclear accident anywhere quickly becomes a potential concern for people everywhere. It is therefore of prime importance that nuclear regulators’ communication strategies take into consideration the expectations and concerns of the public and provide sound information not only for the people of the affected country, but also for citizens worldwide. Public trust is a key element in being able to do so effectively and of particular importance when there are consequences for people or the environment. International co-operation can play a fundamental role in helping to improve crisis communication on national and global scales in the event of a nuclear accident or radiological emergency. These proceedings contain the papers, recommendations and conclusions of the workshop, which was attended by over 180 experts from 27 countries and 6 international organisations.
The Fukushima Daiichi Nuclear Power Plant Accident: OECD/NEA Nuclear Safety Response and Lessons Learnt
English, 68 pages, published: 09/10/13
Volume of the series:
Available online at: http://www.oecd-nea.org/pub/2013/7161-fukushima2013.pdf
- Japanese: 福島第一原子力発電所事故
This report outlines the response of the OECD Nuclear Energy Agency (NEA) and its member countries to the March 2011 accident at TEPCO's Fukushima Daiichi nuclear power plant. All NEA members took early action to ensure and confirm the continued safety of their nuclear power plants and the protection of the public. Consistent with its objective of maintaining and further developing the scientific, technological and legal bases for safe nuclear energy, the NEA has assisted its member countries in their individual and collective responses to the accident. It has also provided direct assistance to the relevant authorities in Japan. These actions are summarised in the report along with lessons learnt thus far. Key messages are offered as a means to help strengthen the basis for nuclear safety and its implementation in all countries using nuclear power.
CSNI Technical Opinion Papers No. 14
Nuclear Licensee Organisational Structures, Resources and Competencies: Determining Their Suitability
English, 16 pages, published: 05/15/12
NEA#6912, ISBN: 978-92-64-99175-0
Available online at: http://www.oecd-nea.org/nsd/docs/2011/csni-r2011-13.pdf
- Français: Avis techniques du CSIN n° 14
The way in which nuclear licensees’ organisations are structured and resourced clearly has a potential impact on nuclear safety. As experience has continually demonstrated, operating organisations with a strong training programme for personnel, adequate resourcing and overall effective leadership and management perform more effectively in times of crisis than those lacking in one or more of these areas. In parallel, the nuclear industry is developing new resource deployment strategies which are making increased use of contractors and leading to changes in organisational structure, which in turn create challenges for the continued safe operation of nuclear facilities. This technical opinion paper represents the consensus among human and organisational factor specialists in NEA member and associated countries on the methods, approaches and good practices to be followed in designing an organisation with a strong safety focus while meeting business needs. It also considers some of the attributes that an organisation which is effectively managing its resources and capabilities might demonstrate.
CSNI Technical Opinion Papers No. 15
Ageing Management of Nuclear Fuel Cycle Facilities
English, 40 pages, published: 12/31/12
NEA#6990, ISBN: 978-92-64-99181-1
Available online at: http://www.oecd-nea.org/nsd/docs/2012/6990-top-15.pdf
- Français: Avis techniques du CSIN n° 15
Managing the ageing of fuel cycle facilities (FCFs) means, as for other nuclear installations, ensuring the availability of required safety functions throughout their service life while taking into account the changes that occur with time and use. This technical opinion paper identifies a set of good practices by benchmarking strategies and good practices on coping with physical ageing and obsolescence from the facility design stage until decommissioning. It should be of particular interest to nuclear safety regulators, fuel cycle facilities operators and fuel cycle researchers.
Challenges in Long-term Operation of Nuclear Power Plants
Implications for Regulatory Bodies
English, 32 pages, published: 09/21/12
NEA#7074, ISBN: 978-92-64-99187-3
Available online at: http://www.oecd-nea.org/nsd/docs/2012/cnra-r2012-5.pdf
- Français: Défis de l'exploitation à long terme des centrales nucléaires
Nuclear power reactors have become a major source of electricity supply in many countries and, based on the experience of safe and reliable operation, many operators have sought and received authorisation for long-term operation beyond the period assumed in the plant’s design. Acceptance of a nuclear power plant for long-term operation must be based on evidence that the plant will operate safely over the extended period of service. This requires an assessment of the current and projected condition of the plant and, in particular, of the systems that perform fundamental safety functions, to ensure that these systems will continue to perform their safety functions during the extended operating period. Programmes for long-term operation must be informed by operating experience and must also consider and assess environmental impacts.
This guidance document is intended to assist regulatory organisations in assessing and approving the long-term operation safety assessments submitted by operators. It outlines the fundamental principles that should govern decisions on authorisation for long-term operation. It also describes regulatory challenges and considerations that may arise in an assessment of a plant for long-term operation.
Computational Fluid Dynamics (CFD) for Nuclear Reactor Safety Applications
Workshop Proceedings, CFD4NRS-3, Bethesda, Maryland, USA, 14-16 September 2010
English, published: 03/22/12
Available online at: http://www.oecd-nea.org/nsd/csni/cfd/workshops/CFD4NRS-3/
Computational fluid dynamics (CFD) is increasingly being adopted in nuclear reactor safety (NRS) analyses as a tool which enables a better description of specific safety-relevant phenomena occurring in nuclear reactors. The OECD Nuclear Energy Agency (NEA) Committee on the Safety of Nuclear Installations (CSNI) has in recent years conducted important activities in the CFD area, including the organisation of three workshops. The CFD4NRS-3 workshop was the third in the series and was held in Bethesda, Maryland, USA on 14-16 September 2010. A total of 200 experts participated. These proceedings contain the 4 keynote lectures, including the synthesis of results for the Tee-junction Benchmark, and the 57 technical papers presented at the workshop.
Main Benefits from 30 Years of Joint Projects in Nuclear Safety
English, 132 pages, published: 05/04/12
NEA#7073, ISBN: 978-92-64-99171-2
Available online at: http://www.oecd-nea.org/nsd/reports/2012/nea7073-30-years-joint-safety-projects.pdf
One of the major achievements of the OECD Nuclear Energy Agency (NEA) is the knowledge it has helped to generate through the organisation of joint international research projects. Such projects, primarily in the areas of nuclear safety and radioactive waste management, enable interested countries, on a cost-sharing basis, to pursue research or the sharing of data with respect to particular areas or issues. Over the years, more than 30 joint projects have been conducted with wide participation of member countries.
The purpose of this report is to describe the achievements of the OECD/NEA joint projects on nuclear safety research that have been carried out over the past three decades, with a particular focus on thermal-hydraulics, fuel behaviour and severe accidents. It shows that the resolution of specific safety issues in these areas has greatly benefited from the joint projects’ activities and results. It also highlights the added value of international co-operation for maintaining unique experimental infrastructure, preserving skills and generating new knowledge.
Nuclear Fuel Safety Criteria Technical Review
English, 80 pages, published: 09/14/12
NEA#7072, ISBN: 978-92-64-99178-1
Available online at: http://www.oecd-nea.org/nsd/reports/2012/nea7072-fuel-safety-criteria.pdf
Most of the current nuclear fuel safety criteria were established during the 1960s and early 1970s. Although these criteria were validated against experiments with fuel designs available at that time, a number of tests were based on unirradiated fuels. Additional verification was performed as these designs evolved, but mostly with the aim of showing that the new designs adequately complied with existing criteria, and not to establish new limits.
In 1996, the OECD Nuclear Energy Agency (NEA) reviewed existing fuel safety criteria, focusing on new fuel and core designs, new cladding materials and industry manufacturing processes. The results were published in the Nuclear Fuel Safety Criteria Technical Review of 2001. The NEA has since re-examined the criteria. A brief description of each criterion and its rationale are presented in this second edition, which will be of interest to both regulators and industry (fuel vendors, utilities).
Nuclear Power Plant Operating Experience
from the IAEA/NEA International Reporting System for Operating Experience:
English, 60 pages, published: 12/31/12
NEA#7120, ISBN: 978-92-64-99193-4
Available online at: http://www.oecd-nea.org/nsd/docs/2012/7120-iaea-nea-irs-2009-2011.pdf
The application of lessons learnt from the International Reporting System for Operating Experience (IRS) is an essential element for enhancing the safe operation of nuclear power plants (NPPs) throughout the world. The IRS provides a mechanism for the exchange of information related to the incident, actions taken, root cause analysis and lessons learnt. This feedback on how to adequately remedy, or avoid, possible challenges and precursors is of paramount importance to operational safety. The IRS improves international awareness of potential challenges, actual incidents and “precursors” in NPP operations. The heightened awareness generated by feedback from operating experience has resulted in numerous improvements to equipment, procedures and training in many NPPs. The application of operational feedback also benefits the design of the next generation of NPPs. Operating experience has demonstrated that design modification issues documented in IRS reports can have a significant impact on safety. The IRS is jointly operated and managed by the OECD Nuclear Energy Agency (OECD/NEA) and the International Atomic Energy Agency (IAEA).
CSNI Technical Opinion Papers – No. 13
LOCA Criteria Basis and Test Methodology
English, 40 pages, published: 09/21/11
NEA#6986, ISBN: 978-92-64-99154-5
Volume of the series:
Available online at: http://www.oecd-nea.org/nsd/docs/2011/csni-r2011-7.pdf
- Français: Avis techniques du CSIN – n° 13
Acceptance criteria for emergency core cooling systems (ECCS) define the maximum temperature and degree of oxidation in order to avoid excessive embrittlement and hence failure of the fuel cladding, which would affect core cooling in the case of a loss-of-coolant accident (LOCA). The criteria are mainly based on experimental data obtained in the 1970s-80s. Several types of tests have been performed to evaluate structural integrity and embrittlement of the cladding under LOCA conditions, and consequently different test methodologies have been used for determining the cladding embrittlement criteria. The current trend towards high burn-up and the use of new cladding alloys has increased the need for international discussions on these test methodologies and acceptance criteria. In response, the NEA Committee on the Safety of Nuclear Installations (CSNI) and its Working Group on Fuel Safety produced this technical opinion paper, which should be of particular interest to nuclear safety regulators, nuclear power plant operators and fuel researchers.
Experimental Facilities for Sodium Fast Reactor Safety Studies
Task Group on Advanced Reactor Experimental Facilities (TAREF)
English, 144 pages, published: 04/15/11
NEA#6908, ISBN: 978-92-64-99155-2
Volume of the series:
Available online at: http://www.oecd-nea.org/nsd/docs/2010/csni-r2010-12.pdf
This report provides an overview of experimental facilities that can be used to carry out nuclear safety research for sodium fast reactors and identifies priorities for organising international co-operative programmes at selected facilities. The information has been collected and analysed by a Task Group on Advanced Reactor Experimental Facilities (TAREF) as part of an ongoing initiative of the NEA Committee on the Safety of Nuclear Installations (CSNI) which aims to define and to implement a strategy for the efficient utilisation of facilities and resources for Generation IV reactor systems.
Improving Nuclear Regulation
NEA Regulatory Guidance Booklets, Volumes 1-14
English, 270 pages, published: 05/30/11
NEA#6905, ISBN: 978-92-64-99162-0
Available online at: http://www.oecd-nea.org/nsd/docs/2011/cnra-r2011-10.pdf
A common theme throughout the series of NEA regulatory guidance reports, or “green booklets”, is the premise that the fundamental objective of all nuclear safety regulatory bodies is to ensure that nuclear facilities are continuously maintained and operated in an acceptably safe manner. In meeting this objective the regulator must bear in mind that it is the operator that has responsibility for safely operating the nuclear facility; the role of the regulator is to assess and to provide assurance regarding the operator’s activities in terms of assuming that responsibility.
The full series of these reports was brought together in one edition for the first time in 2009 and was widely found to be a useful resource. This second edition comprises 14 volumes, including the latest on The Nuclear Regulator's Role in Assessing Licensee Oversight of Vendor and Other Contracted Services. The reports address various challenges that could apply throughout the lifetime of a nuclear facility, including design, siting, manufacturing, construction, commissioning, operation, maintenance and decommissioning. The compilation is intended to serve as a knowledge management tool both for current regulators and the new nuclear professionals and organisations entering the regulatory field.
The Nuclear Regulator's Role in Assessing Licensee Oversight of Vendor and Other Contracted Services
English, 38 pages, published: 03/31/11
NEA#6910, ISBN: 978-92-64-99157-6
Volume of the series:
Available online at: http://www.oecd-nea.org/nsd/docs/2011/cnra-r2011-4.pdf
- Français: Le rôle de l'autorité de sûreté nucléaire dans l'évaluation de la surveillance par l'exploitant des services sous-traités
Contracted services are an integral part of the design, construction and operation of a nuclear facility. Changes in the nuclear industry sector, including varied availability of nuclear expertise, the expansion of the international supply market and the introduction of new technologies, have tended to increase licensees’ use of contracted services. These changes have created challenges for licensees and regulators related to the retention of nuclear expertise, the effective management of the interfaces between the licensees and contractors, and the oversight of contractor manufacturing quality in the context of greater multinational diversity. The regulatory body must address these challenges to provide assurance that the licensees maintain their responsibility for the safety of the facilities, regardless of who provides goods and services or where the activities involved in the supply chain take place. This report is intended to assist regulatory bodies in assessing their current practices for the regulatory oversight of licensees’ use of contractors, and adapting them where necessary to meet the evolving situation.