Maintenance activities fall broadly into four headings. These include the policy implemented by the plant manager including the balance of maintenance activities and the clearing of backlog activities, the planning and scheduling, the procedures, and the conduct of the maintenance (IAEA-TECDOC-1098, 1999; Table 4.4).

Good availability and reliability are the key objectives. Meeting these objectives requires adequate resources to be available to predict the need for the necessary maintenance, to prevent unnecessary activities, and to ensure maintenance is carried out correctly. The majority of work has to be performed during outages and plant availability depends on it being carried out efficiently and successfully. Unplanned outages should clearly be avoided. In nuclear plants today, computer scheduling systems are used to co-ordinate activities and ensure that adequate materials (spares) are available.

Clear maintenance back-logs

Apply maintenance performance indicators

Readiness for eventual unplanned outages

Employ reliability and condition-based decision analysis

Advanced planning of routine maintenance and outages

Use plant-approved procedures in conducting maintenance

Post-maintenance testing to verify satisfactory completion and restart readiness

Use PSA for planning on-line maintenance

IAEA-TECDOC-1098 (1999).

Factors that enhance the effectiveness of maintenance management identified in IAEA-TECDOC-1098 (1999) include, ensuring that maintenance backlog actions do not accumulate and that indicators of various different maintenance activities are recorded. Examples of such indicators include the number of requests, the distinction between preventive and repair maintenance activities and the number of repetitions of work on the same plant components or systems.

On-line monitoring of equipment together with reliability and condition based decision analysis help to reduce preventative maintenance. Preparedness for routine maintenance and outages may be facilitated by advanced planning using mock-ups and other practical demonstrations. These should allow for unplanned outages and should include lists of the different maintenance activities that can be carried out. Regarding technical matters of plant operation, there must be careful monitoring of foreign material in the plant in order to protect equipment. Maintenance should be performed in line with approved procedures, including PSA to facilitate on-line maintenance. Finally, post-maintenance testing must be carried out to verify satisfactory completion of work and to confirm the readiness for the plant restart.