Technically complex systems maintenance

The function of plant maintenance is to preserve and restore the inherent safety, reliability and availabihty of plant structures, systems and components for reliable and safe operation. Maintenance in nuclear installations has specific characteristics that put demands on the way maintenance activities are organized and carried out. These characteristics contribute to the possibility of severe consequences, technical complexity and delayed effects of maintenance. 

The second option considered was use of interception wells. One- or two-pump wells could be constructed at calculated spacings to create a hydraulic trough parallel to the canal to intercept the product. This design was considered more acceptable to the safety officer and the facility engineer, but was rejected by the maintenance foreperson because of the relative complexity of the operation system. The number of submersible pumps and sophisticated electronic controls would have required employment (or training) of technical specialists beyond the cost budgeted under normal operations. 

The buoyancy and floodability systems of retired NSs pending complex decommissioning require continuous servicing and maintenance of technical preparedness to prevent unauthorized sinking. 

To ensure the rehability of industry systems, preventive maintenance strategies are traditionally applied by means of Condition Monitoring (CM). CM is the continuous or periodic measurement and interpretation of the data and information to indicate the technical healthy condition of individual components to determine the needs for maintenance (Leaney Sharpe 1999). CM deals with the acquisition of data and information from both human operators and sensor systems and further with taking corrective or preventive maintenance actions on the components that are to fail (Niu et al. 2010). It means that traditional CM aims to R MM at either a parameter level or an individual components level (Leung Romagnoli 2002). Due to the interdependency among the parameters and the components within complex industry systems, advance R MM development, which is able... 

The assumptions of barrier independence may apply to foreseeable technical failures. There are, however, many case histories in the literature, where unforeseen common-mode failures introduced by the operators or maintenance personnel have caused multiple barrier breakdowns. Due to the complexity of the system, the operators have not been able to understand the situation and foresee the consequences of their actions. 

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