As discussed above, effective PLiM programmes should integrate both safety and operational performance concerns. Regulatory attention focuses on the former, with the primary interest being on obtaining assurances in effective ageing management of SSCs important to safety. In practice, the specific aspects of regulatory requirements and expectations differ considerably between member states. In general, however, they follow the guidance outlined in the IAEA safety standards, safety guides and technical report series [1-20] described in Section 1.4.

The operating NPPs have been licensed on the basis of the requirements established during the design process. To demonstrate compliance with regulatory requirements, the day-to-day operating envelope must be maintained within the bounds of the assumptions of the plant safety analysis. These operating envelopes include:

• Special / critical safety system setpoint limits and system availability.

• Acceptable range of process parameters.

• Allowable equipment configuration and operating states.

Some examples of regulatory approaches and strategies for ensuring the implementation of effective and systematic ageing management practices are summarized in the following sections.

Fig. 5. Process for renewal of operating permit beyond design life time in Spain.