O&M

Recent Nuclear Regulatory Commission (NRC) Component Design Bases Inspection activities have scrutinized empirical approaches used to determine vortex allowances for emergency core cooling system (ECCS) suction sources.

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.

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.