Instrumentation & Controls

In order to operate aging nuclear power plant instrumentation and control systems for up to 60 more years or longer, there must be a smooth transition from existing analog technologies to advanced digital platforms. For this to occur, electromagnetic compatibility concerns related to both qualification testing and the electromagnetic environment must be addressed to ensure safe and reliable operation of these systems within the plant’s electromagnetic and radio frequency interference environment. By understanding the regulatory requirements and sharing implementation experience, digital system upgrades can be installed successfully.

Digital fieldbus technologies, including Foundation fieldbus and Profibus, are increasingly being used with success in the nuclear and fossil fuel power industries. This article compares a conventional control system with a Foundation fieldbus – based digital control system used in a typical circulating water system in a nuclear power plant. As shown in this example, using digital fieldbus technologies can result in significant savings in terms of installation and hardware costs.

Given delays and cancellations of new generating capacity, pushing the existing power generation fleet is more important than ever. At ELECTRIC POWER 2009, multiple presentations explored the premise that an active knowledge management strategy — requiring a blend of digital and human elements unique to each power plant — will help you extract the most productivity from your assets.

As equipment ages in fossil-fueled power plants, component wear leading to machinery failure increases as a result. Extending equipment life requires increased attention to maintenance, and one way to improve maintenance planning is to detect faults prior to failure so maintenance can be scheduled at the most cost-effective, opportune time. This type of strategy benefits from the use of additional sensors, and wireless ones can often be installed with the least time and cost.

In 1999, the Engineering Equipment and Materials Users’ Association (EEMUA) released its general guide to the design, management, and procurement of alarm systems for industrial plants. The guidance document (EEMUA 191), however, is vague about applications to specific facilities, such as electric power plants. This article specifies EEMUA 191 standards and practices applicable to the electric power industry and spells out specific variations in alarming practices that are tailored for today’s power plants.

Existing nuclear power plants are increasingly facing the conversion to digital instrumentation and controls technology. Meanwhile, new nuclear designs have digital technology integrated throughout the plant. Digital controls will soon be inevitable, so how do we make the transition as smooth as possible? Without losing focus on the technical solutions, organizations have to pay attention to the nontechnical issues as well.

Improper pressure-sensing line design or installation is often found to be the cause of poor sensing system accuracy and response time. Here’s how to identify and solve those pesky pressure sensor problems in short order.

The debate over the benefits of using digital bus networks as the communications backbone of new power plants is all but settled. The technology is maturing, and the reliability of digital hardware is superior to that of hardwired systems. Newmont Gold Mining’s 200-MW TS Power Plant is perhaps the power industry’s best example of how a plantwide digital controls architecture can provide exceptional reliability and be significantly less costly to install.

Obtaining accurate data about the performance of a plant’s heat-recovery steam generator is crucial to ensuring the smooth operation and maintenance of the equipment. Software designed to model and simulate HRSG operations can provide valuable information about corrosion and other operational problems.

Boilers have enormous thermal mass and are relatively slow to react. Turbines are nimble and quickly answer an operator’s command. Coordinating an entire plant requires an intimate knowledge of both systems and selecting the right logic tools to bring them together.