O&M

In an exclusive agreement with the EUCG Nuclear Committee, POWER was provided access to some key, high-level performance and operational data from the group’s nuclear industry benchmarking database. All U.S., and many international, nuclear power plants are members of the committee and have contributed to its database for many years. This month we introduce you to the EUCG Nuclear Committee and share sample nuclear operating costs. Look for future reports on other key performance benchmarking metrics during 2010.

Replacing equipment inside a nuclear power plant requires careful planning that begins many months before the plant outage. Entergy has adopted advanced modeling and simulation tools that allow engineers to "walk through" the entire outage in a virtual model, thus avoiding unanticipated surprises.

In 2007, Exelon Corp. began the Centralized Performance Monitoring (CPM) pilot program. The goal was to reduce downtime costs and lost revenue associated with the 25% of unplanned forced losses across its fleet of 17 nuclear power units without additionally taxing existing personnel or adding new personnel.

Corrosion of steel water pipes in the safety-related piping systems of aging U.S. nuclear power plants is fast becoming a safety concern and a significant operational cost, not to mention an indication of potential future liability for nuclear utilities currently constructing new plants or retrofitting existing sites.

The decision to retube a heat exchanger or condenser begins with understanding why tubes are failing. Only when the “why” is understood can the economic replacement tube material be selected. We explore the most common tube material failure mechanisms and then illustrate how to perform a proper life-cycle analysis for that new set of condenser tubes your plant so desperately needs. In sum, there are many reasons to consider getting the copper out of your condenser.

Can wind turbines actually reduce the amount of fossil fuels consumed? A Wall Street Journal analysis concludes that ERCOT utilities will begin to feel the squeeze in their profits this year and to expect the amount of fossil fuels used to generate electricity to be reduced.

Coal-fired power plants that fire low-cost coals or that are equipped with combustion modifications for NO_x controls are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases, significant unit derates, availability losses, and an increase in unburned carbon levels can be attributed to poor combustion conditions that occur as a result of poorly controlled local air/fuel distribution within the boiler furnace. Fortunately, a new generation of combustion optimization technologies is available that uses burner air and fuel controls and spatially distributed combustion monitors to detect and correct local furnace air/fuel distribution imbalances.

When high-temperature boiler feedwater passes through a control valve, the pressure drop can exceed several thousand pounds per square inch, placing extreme stress on the valve body and internal parts. If those parts are not engineered and manufactured to the highest industry standards, there is a very real possibility of the severe conditions damaging or destroying the valve.

Boiler tube failures continue to be the leading cause of downtime for steam power plants. Is your boiler tube failure reduction program showing improvement when compared to programs at peer plants? The EUCG’s recent update of its boiler tube failure study can help you answer that question. The full study is available only to members, but this POWER exclusive presents many of the key results, which could help you improve the operation of your plant.

Once pulverized coal flows have been measured, they can be balanced and optimized. Until then, tuning is simply guesswork. The right way to balance furnace fuel flows is to establish solid baseline performance by proper measurement of fuel flow, fineness, and velocity. Only then can all the coal pipes be accurately balanced and followed by a tune-up of the boiler controls.

Many customer quotation requests provide only the line size, pressure class rating, and valve type. A typical request might read: size 4, Class 900 globe valve. Though this may be enough information to produce a valve quote, it rarely is enough information to size the best valve from both a performance and cost perspective.

There are a number of reasons why your plant might be looking at new water pretreatment equipment in the near future. One common reason is the addition of new generating capacity. Regardless of the type of new generation, you can be sure that it will require additional high-purity water for processes ranging from direct steam generation to power augmentation, NO_x control, and washing the blades of the combustion turbines.

Construction of the Portlands Energy Centre was a logistical dream: A mothballed power plant next door had an active switchyard, natural gas pipeline, and cooling water structure. The new facility put peak power into the Ontario Power Authority’s grid from its two combustion turbines only two years after collecting the necessary permits. The entire plant entered commercial service on April 23, 2009 — six weeks early.

At Royal Pride Holland’s commercial tomato greenhouse, green thumbs and green energy go hand in hand. With a total energy utilization of 95% in this application, GE’s new Jenbacher J624 natural gas – fired engines offer the innovative greenhouse an economical supply of on-site electrical and thermal power, as well as CO₂ fertilization, to support its operations.

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.

One key area at the 800-MW Michoud power station where O&M excellence is evident is in maintaining plant water quality.

The New Source Review (NSR) permitting program was originally created as part of the 1977 Clean Air Act Amendments to ensure that new power generation facilities were properly outfitted with all the necessary air quality control systems when constructed. Plants in operation were exempt until they made plant modifications viewed as beyond “routine maintenance,” a term whose definition has been a moving target. Is it time for the NSR to take a back seat to improved plant efficiency and reduced carbon emissions?

Reducing dust from coal conveyors has moved from a housekeeping chore to a safety challenge, especially with Powder River Basin coals. Here’s what you need to know about the latest coal-handling system design.

The EPA has identified 44 "high hazard" coal ash ponds around the U.S., and a recent Tennessee Valley Authority report indicates that the agency should have known its Kingston Plant pond would have been one of them.

The annual meeting of the Powder River Basin Coal Users’ Group was held in association with the ELECTRIC POWER conference in early May in Chicago. Get a taste of the festivities, technical meetings, and the announcement of the group’s 2009 Large and Small Plant of the Year winners in this conference report.

Cavitation is defined as the phenomenon of forming and imploding vapor bubbles in a region where the pressure of the liquid falls below its vapor pressure. Cavitation and the resultant damage can occur in any fluid-handling equipment, especially in pumps. Technological advances in industrial protective coatings and composite repair materials have made it possible to repair pumps operating in a cavitating environment rather than simply replacing them after damage occurs. Cavitation-resistant (CR) elastomers have the ability to retain adhesion under long-term immersion, dissipate energy created under high-intensity cavitation, and provide outstanding resistance to corrosion and other forms of erosion.

The Springerville Generating Station in Springerville, Ariz. (Unit 3 was POWER’s 2006 Plant of the Year), uses two lined ponds to hold water collected from its cooling towers. With the construction of Unit 4, the plant’s owner, Salt River Project (SRP), one of Arizona’s largest utilities, wanted to increase the capacity of pumps used to move effluent from one pond to another to avoid the possibility of overflow. SRP engineers wondered if using a vertical turbine pump on a floating barge would improve managing the water levels in the two ponds.

ASME’s latest revision of its Recommended Practices for the Prevention of Water Damage to Steam Turbines Used for Electric Power Generation: Fossil-Fuel Plants, ASME TDP-1-2006, contains much important design and operating advice that is proven to protect steam turbines. However, many in the industry are not as familiar with the update as they should be. This article provides a concise overview of this critical design standard.

Reducing the minimum load at which a steam turbine can reliably operate is one way to increase revenue for marginal base-loaded units during periods of low electrical demand. For this reason, it is not unusual to see merchant plants operating at "super minimum" load levels that are well below the typical 25% rated full-load limits. However, such units are operating well outside the original equipment manufacturer (OEM) design basis, and owners may experience undesirable damage to their turbines for a number of reasons. That’s why it is important for owners to understand the trade-offs and risks that come with such operation.

Performing regular oil changes on remote generators is far from simple or cost-effective. Here’s how one firm harnessed technology to extend oil change intervals from one week to two months.

The welding of dissimilar metal joints in new and retrofit power plant boiler tubing has long proved challenging. New plants designed to operate at higher temperatures and pressures require advanced alloys and a filler metal that produces reliable welds. EPRI recently developed and sponsored the commercialization of a new filler metal. Its first application is the fabrication of boiler tubes for American Electric Power’s ultrasupercritical John J. Turk, Jr. Power Plant.

Increasingly fierce competition driven by deregulation and privatization is putting downward pressure on power plant operations and maintenance (O&M) budgets. Recently, lower natural gas prices have pushed natural gas – fired combined-cycle plants higher up in many utilities’ dispatch order in some regions, a welcome change from the twice-a-day cycling experienced by some plants during the past few years. However, with more operating hours comes more interest in plant operating availability, and that means increased emphasis on reliable gas turbine operation.

Southern California Edison’s (SCE) 2,250-MWe San Onofre Nuclear Generating Station (SONGS) recently took receipt of a new and upgraded generator rotor for one of its two Alstom steam turbine generator units (Figure 1). Following the successful installation and flawless start-up of this new rotor in the Unit 2 generator, the former Unit 2 rotor was […]

In the wake of the recent U.S. Supreme Court ruling related to cooling water intake practices at large power plants, many utilities are relieved to be off the hook as far as implementing expensive control upgrades to protect fish and other aquatic organisms.

Combustor design simulation requires the resolution of complex geometry, turbulent flow patterns, heat transfer, and detailed chemistry. Although computational fluid dynamics (CFD) can simulate the reacting flow in realistic geometries, it requires the use of severely restricted chemistry models that are too simple to accurately simulate emissions and operational stability. A new simulation tool is now available that eliminates this CFD shortcoming while significantly reducing computing time.