Category Archives: Infrastructure and methodologies for the. justification of nuclear power programmes

Operational phase

Safe operation is assured by effective design, acquisition and installation of plant and equipment that satisfy the design requirements. A licensing process and quality assurance measures must be established to ensure that these requirements are satisfied.

Throughout the operating life of the plant, it is the operating organisa­tion’s responsibility to ensure that the plant design fidelity is maintained and that it is operated and maintained in accordance with design require­ments. Periodically regulators will require a design assessment to determine such things as the impact of in-service aging on the design characteristics and to assess if any countermeasures are required in the form of replace­ment components, modifications or changes to operating conditions.

Nuclear site licence conditions will define the responsibilities of the oper­ator for ensuring safety and environmental protection.

The licensing process and the means of enacting licence requirements are discussed in Chapter 20, and operations in Chapter 23.

5.1.4 Decommissioning

The operating organisation is responsible for making full provision for the costs of decommissioning and disposal of hazardous waste. The financial provisions must be set aside throughout the operating lifetime of the plant. In addition the operator must ensure that the hazardous waste arisings are kept to an absolute minimum, that they are effectively stored until final disposal and that a full inventory of the hazardous waste is maintained. Prior to closure of an NPP, the operating organisation is required to seek a license for the activities involved.

Decommissioning is covered in detail in Chapter 24.

Major regulatory activities during the licensing process


The siting process for a new nuclear installation is divided into two stages: site survey and site evaluation. The government or the regulatory body identifies the potential sites and candidate sites on the basis of a set of defined criteria. Siting survey and evaluation is considered in Chapter 18.

Site evaluation is the actual selection of the site and aims to confirm the acceptability of the final site selected and to establish the parameters needed for the design of the nuclear power plant. The regulatory body should establish specific safety requirements for site evaluation, including requirements for the process of authorizing the site selected. Consequently, the regulatory body makes the review and assesses the site evaluation report, and makes a regulatory decision regarding the acceptability of the site selected and the site-related design bases.

The site evaluation process continues throughout the entire lifetime of the nuclear power plant to take into account changes in the site character­istics, in evaluation methodologies and in safety standards.

Sources of further information and advice


The IAEA is the world’s centre of cooperation in the nuclear field. It was set up as the world’s ‘Atoms for Peace’ organization in 1957 within the United Nations family. The Agency works with its Member States and mul­tiple partners worldwide to promote safe, secure and peaceful nuclear tech­nologies. Its website is of particular interest for the readers of this book and more detailed information can be found on safeguards, safety standards, nuclear law, international conventions and technical matters related to fuel cycle installations and nuclear power plants.


WNA’s role is to support the global nuclear energy industry through expert Working Groups focused on industry goals and concerns representing the industry in such key policy forums as IAEA, ICRP and UN climate change talks, the WNA Public Information Service (the world’s leading resource for facts on nuclear energy), WNN (the foremost nuclear news service), the Biennial WNA Market Report (an authoritative projection of the global nuclear fuel market), the industry’s pre-eminent WNA Symposium and the World Nuclear Fuel Cycle conference, support for WNTI and Women-in — Nuclear operating the World Nuclear Communicators Network to foster best practice in public information on nuclear energy, and the WNA Nuclear Energy Index of globally traded nuclear stocks.

Regulatory support and research

Support for the regulatory body is available in the form of technical or other expert professional advice or services as necessary to assist the body in its regulatory functions; however, this does not relieve the regulatory body of its assigned responsibilities, and independent decision making still has to be undertaken by the regulatory body. In making decisions, the regulatory body needs to consider the necessary means to assess advice provided by advisory bodies and the information submitted by the licensee. The rela­tionship between regulatory body competence and the extent of the techni­cal support is a delicate balance that needs to be considered from the initial stages of the establishment of a regulatory body.

There are several approaches to receiving technical or non-technical support. For example, independent advisory bodies may provide advice on a temporary or a permanent basis, or independent expert opinions can be sought from consultants with experience in the specific field. In general the advisory bodies advise and confirm whether the regulatory body has prop­erly addressed relevant safety issues in licensing reviews. For specific areas where expertise is not available within the regulatory body, a specific con­tract or services from research centres or academic institutions may be used to provide analysis of technical details and background. Finally, another approach is the establishment of a dedicated support organization working on a daily basis with the regulatory body.

The composition of advisory bodies may be derived from other govern­ment departments, regulatory bodies of other States, scientific organiza­tions, technical experts, non-government organizations and the regulated industry. Some advisory bodies can bring broad perspectives and advice to bear on the formulation of clear, practical and balanced regulatory policy and regulations. Other more technical bodies composed of members with a range of technical skills can be established to evaluate and advise on complex technical issues.

In general, the work carried out by technical support organizations involves conducting independent confirmatory analyses or research, techni­cal assistance on the resolution of specific regulatory issues, and the devel­opment of technical bases for safety policy and regulations. In order to develop these activities, the size, scope and responsibilities of the external support organizations need to be clearly specified.

In order to avoid any conflict of interest, as a minimum, the support provided to the regulatory body should not be provided to the licensee in the same subject area and vice versa. If this is not possible domestically, then the necessary advice or assistance may be obtained from organiza­tions in other States or from international organizations that have no such conflicts of interest. However, in cases where a gap in expertise in a significant safety area is identified within the State, the regulatory body needs to take the appropriate steps to build the necessary competence to fill this gap, using other governmental organizations if applicable (IAEA, 2010a).

The regulatory body may need other external technical services such as personal radiation dosimetry and environmental radiation monitoring, in­service testing and inspection, maintenance of special technical equipment, and metrological activities.

Regulatory research may serve to enhance the development of knowl­edge, competence and ownership in nuclear science and technology. Regulatory bodies use research, when necessary, for independent analysis and in order to formulate conclusions that enable regulatory decisions to be taken. Relevant areas of research include reactor physics, thermal hydraulics, materials sciences, strength analysis and probabilistic safety assessment. National research activities need to be considered and initiated as early as possible when considering launching a nuclear power pro­gramme; these programmes may be initiated within the existing institutions or within newly created institutions. For regulatory purposes, the national research programme should be focused on areas that are vital for safety.

Development, functions and management system of the regulatory body

4.1.2 Developing the structure of the organization

The regulatory body is structured and organized in order to fulfil its respon­sibilities and to perform its functions effectively and efficiently. There are key elements to consider in the organization of the regulatory body.

Primarily the regulatory organization needs to take into account its regu­latory functions: licensing; review and assessment; inspection; enforcement; and the development of regulations and guides. The objective of these regu­latory functions is the verification and assessment of safety in compliance with regulatory requirements.

The national legal arrangements, regulatory infrastructure and policy direction given by the State represent one key element of the organization.

National legal arrangements and structure have a significant influence on the regulatory body, including the need to consider the requirements of regulatory bodies in other areas of industry (IAEA, 2010a).

The regulatory body will need to decide whether or not to utilize techni­cal or other expert professional advice or services to assist it in discharging its responsibilities; this decision will influence the body’s own organizational structure. The professional advice or services could be provided by advisory bodies, dedicated technical support organizations, consultants, other regula­tory bodies or national and international agencies. However, the regulatory body should ensure that its organization has sufficient resources with the necessary competence to allow it to make effective decisions.

The regulatory body’s organizational structure will also be affected by whether its staff are all located in a single central headquarters or whether some staff are regionally located. In considering whether to locate staff regionally there are a number of factors that need to be taken into account, including the type and geographical spread of the nuclear power plants, the number of inspectors and the amount of time they need to spend on site to fulfil their duties.

The scope of the regulatory activities in relation to safety, security and safeguards may be comprehensive or may be distributed in different regula­tory organizations; this latter approach may be necessary because of the wide range of the activities covered by the regulatory oversight of planning, licensing and operation, i. e. construction, manufacturing of components, training and qualification, technical specifications, maintenance, surveil­lance testing, management of modifications, fire protection, radiation pro­tection, emergency preparedness, and the management system of both the operating organization and the various suppliers.

As a case in point, licensing activities essential to the development of a nuclear facility site may be carried out either by very few or by a larger number of governmental authorities, depending on the structure and func­tions of the regulatory body as established by law. In some States, it is the practice for the regulatory body to approve the various suppliers involved, following audits and inspections of their management systems. Once the regulatory body issues the construction licence, construction starts, includ­ing the manufacture of important safety (and safety-related) systems and components. The construction should proceed in a manner that ensures quality and safe operation. In this phase, the operating organizations, and the regulatory body as applicable, should monitor continuously the con­struction of safety-related structures, systems and components, both at the site and at manufacturing facilities, to ensure that the construction is in accordance with the approved design.

In a regulatory organization, each of its functions may be assigned to an organizational unit with its own specialists. However, it is often practical and efficient to group the specialists in a matrix such that each organiza­tional unit that is assigned responsibility for a particular function can draw on the necessary specialist skills. There is a particular need for interaction and integration between assessment and inspection functions.

The nuclear power planning programme needs to consider the number and type of nuclear power plants to be regulated in a timeframe. This needs to be considered sufficiently in advance in order to formulate a comprehen­sive regulatory plan in terms of regulatory resources so that effective regu­latory oversight can be provided at all times to all nuclear plants.

In general, in the early stages, a new regulatory body should review the experience from regulatory bodies and appropriate organizations within the State (e. g. national research organization) and from other States (includ­ing international organizations) and use this to inform its initial organiza­tional development including the minimum core organization and staffing needs. The use of an advisory body made up of experienced national and international experts should be considered to assist this process.

The regulatory body should regularly review its organization and make adjustments as necessary to take account of its operational experience, to address regulatory changes, and to address other changes in the regulatory environment or processes. Other factors to be considered include staffing and funding issues and the outcome of both internal and external audits, evaluations and peer reviews. Lessons learned from nuclear and non­nuclear experiences are elements to consider when the organization is reviewed.

Importance of organisations for safe operation

The effective enactment of the roles and responsibilities associated with the construction, commissioning, operation and decommissioning of nuclear power plants depends on the effectiveness of the operating organisation. Throughout the lifecycle each phase of activity will have its own specific needs and challenges. Operating organisations must adapt and develop to meet those requirements. In addition the lifecycle of a NPP will last several decades so the challenge of maintaining organisational effectiveness over the full term of the lifecycle must not be underestimated.

Worldwide experience in peer reviews, OSART missions and event anal­ysis demonstrate that most events and performance deficiencies identified

in those programmes have their genesis in organisational and human per­formance factors.

Conversely, the US utilities achieved one of the most outstanding per­formance improvements on record. At the time of the Three Mile Island Accident in 1979, there were approximately 104 NPPs in service with an average Unit Capability Factor (UCF) of just 60%. Today, with the same number of plants in service, the figure is approximately 92%. That achieve­ment is almost entirely due to improvements in organisational effectiveness and the ability to learn from experience.

One of the great features of that improvement is that it is well docu­mented and readily replicable. Today organisations such as the IAEA, WANO and INPO facilitate the identification, sharing and promotion of good practices between utilities worldwide through, for example, their Technical Exchange, Peer Review, OSART, Technical Publications and Good Practices Programmes.

Design safety

The regulatory body establishes the nuclear safety principles and issues regulations on design; it needs to be able to evaluate the safety of the proposed design by reviewing and assessing the safety documentation (e. g. design basis, the safety analysis reports) and verifying the compliance of the design with regulatory requirements. The design basis is the range of conditions and events explicitly taken into account in the design of the nuclear installation, according to established criteria, such that the nuclear installation, through the planned operation of safety systems, can operate under these conditions and events without exceeding authorized limits. The design should be reviewed by the regulatory body considering the design basis accidents and design extended conditions. The design basis accidents (DBAs) are defined when key safety plant parameters do not exceed specified limits, with no or only minor radiological impacts, both on and off the site, and do not necessitate any off-site intervention mea­sures, and DBAs shall be analysed in a conservative manner. The design extended conditions (DECs) consider that the plant can be brought into a controlled state, the integrity of the containment is maintained (the con­tainment shall cope with core melt situation) and significant releases are practically eliminated. DECs may be analysed using a best-estimate approach. For those conditions that are not practically eliminated, design provisions shall be made such that only protective measures that are of limited scope in terms of area and time are necessary for the protection of the public, and sufficient time is available to implement these measures.

The IAEA established safety design requirements in 2000 (IAEA, 2000). The analysis of the operating experience and the comments by Member

States have recommended to revise the document. The revision has already been approved by the IAEA Committee of Safety Standards (CSS) but not yet published (IAEA, 2011b). Although the structure of the revised version is similar, it introduces some new concepts such as Design Extension Conditions, aimed at considering extreme circumstances.


Under WNA, the World Nuclear University is a global partnership commit­ted to enhancing international education and leadership in the peaceful applications of nuclear science and technology. The central elements of the WNU partnership are the global organizations of the nuclear industry — the World Nuclear Association (WNA) and the World Association of Nuclear Operators (WANO) — and the intergovernmental nuclear agencies — the International Atomic Energy Agency (IAEA) and the Nuclear Energy Agency of the Organization for Economic Co-operation and Development (OECD-NEA), and the leading institutions of nuclear learning in some 30 countries. WNU programmes are intended to complement existing institu­tions of nuclear learning by filling unmet educational and training needs on the international level. These programmes are designed to capitalize on the WNU’s strength as a partnership that draws on support from industry, governments and academia. To date, WNU programmes have focused on building nuclear leadership and providing orientation on the main issues that affect the global nuclear industry today. As of September 2009, nearly 2000 nuclear professionals and students from over 60 countries had partici­pated in such programmes called Summer Institute. Plans for future WNU programmes envisage widening their scope to include fostering industry and regulatory consensus on issues affecting nuclear industry operations, building policy consensus on a sound multinational framework to govern expanding nuclear commerce and power production, facilitating multina­tional academic cooperation, and enhancing public understanding of nuclear science and technology.

Responsibilities of the nuclear operator in nuclear power programmes

J. MOARES, Independent Consultant, UK

Abstract: The role of the operating organisation commences with the strategic and economic decision by the sponsoring organisation to construct a nuclear power plant. All phases of the lifecycle of a nuclear power plant are subjected to controls and regulations designed to protect the public and the workforce from any risks associated with their operation. The role of the operating organisation covers design appraisal, site appraisal and infrastructure development, the design, development and maintenance of the of the operating organisation, construction, commissioning, operations and maintenance and decommissioning. The operating lifetime will last many decades and throughout that time the organisation will need to adapt to the changing roles, and be refreshed to cater for the effects of aging in the workforce. This chapter seeks to characterise the roles at each of the phases of the life cycle and share insights into the ways in which they can be enacted.

Key words: nuclear power plant, operators, safe operation, safety responsibilities.

5.1 Introduction

Nuclear power plants (NPPs) exist in order to satisfy a public need for the safe, reliable and economic supply of electricity. NPPs must be designed, manufactured and constructed to standards that ensure that the risks associ­ated with their operation are mitigated and the benefits to society are achieved. Governments and regulators are responsible for specifying design standards that will satisfy the safety requirements and for approving and licensing designs submitted for construction.

Regulators specify the conditions under which the plants must be oper­ated and maintained in order to ensure compliance with the design require­ments, and to safeguard the workers, the public and the environment from NPP-derived hazards. The conditions are detailed in site-specific nuclear site licences and authorisations.

The operating organisation is responsible for the safe and economic operation of the plant and for ensuring that all activities are conducted in compliance with the nuclear site licence conditions. In order to satisfy those requirements, the operating organisation must ensure it has the resources and competencies to fulfil the conditions of the site licence throughout the lifecycle of the plant.

This chapter will define the responsibilities of the operating organisation and the means of enacting them.