Year
2014
Abstract
Nuclear power plants should have robust safety systems designed to prevent accidents, and decrease its effects should one occur. All of these systems are maintained and oversee regularly, and upgraded when necessary, to ensure the plants meet or exceed strict safety standards established by associating Nuclear Safety Commission (NSC).Emergency Shutdown (ESD) Systems are used across a wide range of industries and offer personnel, asset and environmental protection by means of instantaneous, fail safe, plant immobilization. ESD system works by minimizing the consequences of an on-site emergency by establishing and identifying safety critical signals which are then controlled and dealt with to put the entire facility into a safe “stop” situation. A series of pre-engineered functions will then bring the facility back into full operation once the cause of the shutdown has been determined and dealt with ESD systems are required to be both fail-safe and highly available to mitigate the effects of accidents when they occur. PLC systems can be applied to meet both ESD requirements, but careful consideration to safety must be given throughout the life of the system. The advantages of PLC-based ESD system is great flexibility, easiness of interfacing, and cost- effectiveness. There is, however, a great need for standards that directly address these applications. This document provides an overview of the use of programmable logic controllers (PLCs) and SCADA (supervisory data acquisition system) as automation sophistication in ESD systems. This discussion covers the advantages of PLC and SCADA in ESD and design principles, safety analysis, design, testing, installation, and maintenance over the life of the system. The development, use, and maintenance of a system's documentation can significantly improve the quality and safety of the system. Documentation obviously provides the foundation for understanding the system. In addition, the development and maintenance of the documentation facilitate communication among the various disciplines; operators, system designers, programmers, instrumentation and controls engineers, electrical power system engineers, and maintenance and management personnel. The documentation, then, provides a platform for intense scrutiny of the system.