July-August 2019 NPJ

Nuclear Plant Journal, July-August 2019 NuclearPlantJournal.com 35 (Continued on page 36) Kenneth Lunz Ken Lunz is currently the Director of Safety Systems in Westinghouse Electric Company’s Global I&C organization, esponsible for the mplementation of digital safety systems n new and operating lants. He has worked in the field f I&C for nuclear ower plants his ntire 37-year career at Westinghouse, holding positions in design engineering, roject management, marketing and engineering management. Mr. Lunz has been awarded eight patents related to I&C for nuclear power plants. He holds a Bachelor of Science in Electrical Engineering and a Master of Business Administration from the University of Pittsburgh. Many innovative I&C solutions that were further refined with the AP1000 plant design are now being incorporated into upgrade projects for the existing operating fleet. There are many benefits of the newer technology for the operating fleet: It is more intuitive, easier to operate and maintain, and allows a newer generation of operators to quickly learn the systems. These benefits increase as additional older systems are updated to the newer digital platforms. The full performance benefits of the newer technology are realized with fully integrated I&C systems. Main Control Room The main control room as developed for the AP1000 plant has a minimal set of dedicated switches and indicators located on a primary dedicated safety panel and secondary safety panel for manual safety actuations. Westinghouse developed the main control room according to the U.S. Nuclear Regulatory Commission’s NUREG-0711, “Human Factors Engineering Program Review Model,” to apply the most advanced human factors engineering principles to its design. The main control room contains large, wall- panel overview displays; channelized Class 1E safety displays; and non-safety operator consoles. With the entire plant controlled and monitored with modern digital I&C systems, plant operators can work much more efficiently due to the availability of information to support plant operations and maintenance. For example, electrical and mechanical systems that traditionally have had only minimal interfaces in the main control roomare now fully accessible because these systems are monitored and controlled by the integrated I&C system. This enables operators to readilydetermine equipment operability and availability based on knowledge of the electrical distribution to endpoint equipment. Detailed diagnostic information is also available through use of advanced bussed interfaces to mechanical equipment and packaged systems that support asset management and early indication of plant issues. The advanced alarm presentation system synergizes this information for presentation to the operators to minimize their burden. Component Interface Module The key to the fully integrated safety and non-safety system control room is the Westinghouse- designed Component Interface Module or CIM. This Class 1E qualified CIM provides command prioritization and component control of discrete plant components to allow for integrated safety and non-safety system control of safety components. It is based on Field Programmable Gate Array technology that has been extensively tested and verified to ensure integrity in all normal and abnormal conditions. This ensures that the safety functions always override the non-safety controls in accident conditions but do not impede non-safety control during normal operation. Westinghouse originally implemented the CIM in a major I&C upgrade at a plant in Sweden and has now applied a more advanced version to the AP1000 plants. These advancements include redundant solid-state actuation circuits in place of relays, redundant bus interfaces to the safety system and redundant power supplies. The component oriented nature of the CIM keeps all the input/output signals associated with the component together on the same CIM along with a set of manual control switches and indicators for local operation. Alarm Presentation System The advanced alarm system is a modular, highly configurable software- based system that consists of redundant alarm servers, large LCD monitors, and alarm management software that runs on operator workstations. The alarm management software provides features intended to minimize operator distractions – for example, it prioritizes alarms, uses color and audio coding, and has advanced alarm suppression options to enhance operators’ focus on priority issues. Operators have a broad view of plant status and can view selected information from the entire plant or a specific system process. Operators can also use the overview displays to view plant trends. Digital Rod Control Westinghouse introduced the third generation Westinghouse digital rod control system in theAP1000 plants and in Korean-designed APR1400 plants. This latest generation incorporates more than 20 years of digital rod control experience from systems installed in operating nuclear plants since the 1990s. The third generation Westinghouse digital rod control system removes all single point vulnerabilities with redundant safeguards to help prevent control rod drops and provides advanced diagnostics for ease in troubleshooting. It also improves rod control to support daily load follow. Westinghouse adapted the modular design of the latest generation digital rod control system for operating plants and introduced the Westinghouse Advanced Rod Control Hybrid (ARCH). ARCH provides an upgrade path for the power cabinets and the logic cabinet, addressing obsolescence issues, and simplifying the overall design in operating plants. ARCH can be seamlessly integrated into existing I&C systems for Westinghouse r i i p o p e p