Any justification exercise, whether relating to a simple new medical or radiation application, a new nuclear power programme or any other nuclear installation or relevant activity, should be undertaken within a formal regu­latory process. Such a process will provide a list of projects which can be submitted for justification, define the corresponding justification authority, incorporate guides for submitting the different types of justification, provide for effective stakeholder participation and define the legal value and scope of any decision taken.

The justification principle is included in most regulatory requirements concerning radiation protection but has only been developed for radiation applications in some countries, and only in the United Kingdom have regu­lations been fully developed for justification of nuclear power installations. In 2004, new regulations were enacted to develop the justification principle (UK, 2004). These regulations included 27 articles and four schedules; among other legal aspects, they define those installations and practices that should undergo a justification request, the process for requesting justifica­tion, the authorization authority and public participation in the process.

In March 2008, the UK Secretary of State for the then Department for Business, Enterprise and Regulatory Reform (BERR), in consultation with the Department for Environment, Food and Rural Affairs (DEFRA), issued a guidance document (UK, 2008) specifically aimed at applicants wishing to seek a decision under the justification regulations to justify new nuclear power. That guidance sets out the process for submitting applica­tions and outlines the decision-making process for such justification. The guidance note defines justification as ‘a high-level assessment to assess the benefits and any health detriment associated with a particular class or type of nuclear practice’. It clearly indicates that ‘it does not, by itself, authorise the construction or operation of any particular plant or activity, nor does it replace the detailed safety, security and environmental assessments carried out by the nuclear regulators’.

The BERR interpretation of justification requires an assessment of the potential radiological health detriments associated with the practice, but also other potential detriments that could be significant when considered against the benefit derived from the practice. Following this guidance, the Nuclear Industry Association (NIA) submitted to the Department of Energy and Climate Change (DECC) — considered to be the justification authority in this particular case — an application for justification of new nuclear power stations (NIA, 2008), with reference to the two designs (the AP1000 from WEC, and the EPR from AREVA) which, at that time, had successfully completed Step 2 of the Generic Design Assessment (GDA). This subject is developed further in Appendix 1.

The responsibility for preparing, drafting and submitting an application for justification may lie with an ad hoc group of specialists, with any industry or association of industries, or with any licensee responsible for a given installation. Subjects to be justified may include a national nuclear power programme, a cluster of nuclear power designs, a nuclear research centre (including research reactors), a fuel cycle management policy, or the trans­portation of nuclear materials and radioactive waste.

In all cases, there should be a justification authority. Indeed, the nature and aims of the justification principle require the existence of a justification authority with the capacity to decide whether a given request should be considered justified. The rank of such an authority may vary in accordance with the magnitude and the nature of the issue to be justified. The decision to introduce a nuclear power programme for the first time, or to construct large installations, should lie under the authority of the head of government or a suitable minister of state, generally under parliamentary control. The decision to build a final repository for long-life high-level waste should also be the decision of the government. In both cases, the basis for the decision should be a justification exercise produced by national experts and incor­porating external advisers, when needed.

The decision to enlarge the service life of operating nuclear power plants beyond the life assigned in the original design should be taken by a minister of state or similar authority responsible for energy. A justification report should be prepared and submitted by the plant owner/operator to the jus­tification authority. In this particular case, the nuclear regulatory organiza­tion has to verify that such longer-term operation will maintain the design basis, and that the ageing process can be managed. The justification will not impede or impair the safety evaluation of individual plants by the regula­tory authority; it simply ensures that such types of request are considered properly.

The process should be open to stakeholder involvement through a formal process, as explained by the IAEA International Nuclear Safety Group (INSAG) (INSAG, 2006). The intensity and coverage of stakeholder par­ticipation may vary considerably: it may cover the whole country, and even neighbouring countries, such as when considering embarking on a new nuclear power programme or deciding the location of a final waste reposi­tory. It could be limited to a particular state or province and their neigh­bours, as in the case of the construction of a new nuclear installation, or be limited to the neighbourhood and the area of influence of an existing instal­lation. But whatever the case, there should be a well-established procedure for stakeholder intervention, and the justification authority should make its decision after a careful analysis of all their submissions.

A justification decision only implies that the issue requested is acceptable and can be put into practice, for example that a proposed nuclear power programme can be conducted within the limits and conditions stated in the decision, and that nuclear installations and relevant activities are acceptable as described. The decision is not a licence and does not compromise any regulatory decision, nor the regulatory process itself. One of its main values resides in the fact that the decision takes into account other types of con­sideration beyond nuclear safety and security, and radiological protection, and that it has considered the opinion of society at large.