Steam Turbine and Generator Inspection and Condition Assessments

Nuclear steam turbine-generator sets are critical assets requiring periodic assessment for continued reliable operation. Current market conditions may dictate that these assets are operated in modes not considered in the original engineering design, potentially leading to acceleration of damage mechanisms.

Our Turbine/Generator Group consists of industry-experienced engineers and technical staff that have developed and implemented numerous methodologies for evaluating the current condition of many types of generating equipment. Whether the issue is rotor bore condition, solid rotor assessment, inspection of keyways, dovetails, or other critical component in a turbine-generator assembly, we have the ability to apply state-of-the-art inspection and analytical methods in order to provide the most accurate results. This allows for re-inspection recommendations that are made with confidence, and helps to prolong asset life.

Advanced Solutions for Complex Issues

The general concept of turbine/generator operation is straight forward. However, performing accurate and productive inspections and condition assessments requires a detailed understanding of the complexities associated with turbine and generator operation, and also a familiarity with the wide variety of machine types and OEMs, as well as proper materials, NDE, and related analytical method expertise.

With regard to advanced NDE methods, it may be critical to tailor the inspection to the specific type of component and damage that is being targeted. In some cases, this may require designing and fabricating project-specific calibration blocks or specialized phased array transducers in order to maximize the resolution of the inspection. This in turn allows for greater confidence in the minimum detectable flaw size, which in turn leads to more accurate predictions of remaining life. Familiarity with industry issues, including known flaw locations and orientation in similar machines, allows for focused inspections that optimize inspection dollars and minimize outage times.

Once inspections have been performed, numerous analytical methods can be implemented, depending on the specific component of interest, in order to 1) develop an accurate model of the area(s) of interest, 2) evaluate stress levels under various loading conditions, 3) perform predictions of critical crack size or crack growth rates, 4) assess the potential for stress corrosion cracking, or 5) evaluate the effects of material property variations on system performance.

Modifications of turbine, generator, or rotating exciter in the turbine train, or a turbine train made up of rotors from mixed OEMs, can potentially shift resonance frequencies closer to operating frequencies. Torsional vibration can be detrimental to turbine train longevity. Insurance companies have also become aware of the importance of torsional vibration. Structural Integrity offers torsional vibration monitoring and analysis to address these situations. (Ask Miroslav Trubelja to review this paragraph.)

Regardless of the specific need, Structural Integrity’s Turbine Generator Group can put together a multi-faceted approach to inspect, analyze, and improve the confidence level for any turbine-generator system. For additional information on our Turbine and Generator Inspection and Condition Assessment Services, call 877-4SI-POWER or email us at .