A commonly accepted principle is that the direct responsibility for safety of a nuclear plant rests with the utility. This contrasts the role of the regulator whose function is to set the safety goals and to ensure these are met. As for differences in regulatory focus across different countries, there are also differences in relationship between utility and regulator. This relationship is more formal in some countries than others. However, in most countries, there is a desire from both utility and regulator to promote an increasingly collaborative working relationship and encourage open dialogue between the two parties.

It is the responsibility of the licensee to have in place emergency operating procedures for the plant and also emergency planning procedures for the whole nuclear plant complex (Pershagen, 1989). These include instructions for plant operation for accidents within the design basis but also procedures for severe accidents beyond the design basis (Table 3.7).

Operating rules for design basis accidents (event oriented)

Emergency operating procedures for beyond design basis severe accidents (symptom oriented)

Pershagen (1989).

Emergency planning procedures include the establishment of an organisation to implement the plan, including any required accident management actions. Emergency planning procedures beyond the plant boundary usually are the responsibility of other local and/or national authorities. However, the licensee must be prepared to liase and co-ordinate operations with these authorities.

The utilities are regularly audited by safety authorities to ensure that all the required frameworks/organisations are in place for the continued safe operation of their nuclear plants. An important principle is that the safety case is ‘owned’ by the plant, i. e. that a utility has in place a sufficient number of adequately trained staff who understand the relevant issues and are suitably qualified and experienced personnel (SQEP).

Reactor vendors clearly perform an integral part in ensuring the operational safety of a plant. They may be called upon by the utility to provide services not just at the design and initial licensing stages but also during the lifetime of the plant. There may be a requirement to back-fit more efficient safety systems, or to purchase fuel from a new fuel vendor (the latter is more performance — than safety-related). In the US, there has been a push by some vendors to license specific designs with the USNRC. It is expected that this would substantially simplify the licensing process of that particular design, e. g. in countries outside the US.