Utilities

RTI was contacted by representatives of Mesquite Power LLC to determine the most probable cause of the failure of a single-phase generator step-up (GSU) power transformer, in a bank of four, at their Arlington, AZ power plant. Based upon RTI’s investigation the failure was caused by a rapid expansion of gas in the high voltage turret which caused damage to the high voltage lead structure.

Electric power distribution systems are well integrated into the public domain of their service areas.  Accidents and equipment failures are not unexpected and may or may not involve non-utility property and/or personnel.  The need has been recognized to provide utilities with the resources to conduct an enhanced root cause analysis of incidents by implementing forensic engineering investigation procedures.  Utility personnel will be better prepared to respond to all distribution system incidents more effectively and to investigate them more thoroughly.  The results of the

Two out of three offshore intake structures, called velocity caps, for a power plant cooling system, failed.  RTI performed an underwater examination; sampling and condition survey; removal, cleaning, and inspection of the damaged members; and instrumentation of the intake structure.  Included in the engineering analysis was a review of the construction method, structure design and fastener system, and an analysis of the wave loads.

A 460MW generator failed suddenly and without warning.  The unit was running at full load (445MW) when a phase B to phase C fault occurred in the stator leads and the unit tripped off-line in approximately four cycles.

RTI performed a site investigation and inspection and provided a team of engineering metallurgists and electrical engineers to determine the cause of the failure.

An electrical fire occurred in an underground flood control pump station, which housed four water pumps used to prevent flooding in vehicle tunnels.  The fire severely damaged the motor control centers, including current transformers, cables, circuit breakers, buswork and the lighting system.  Power to the station was lost.

The Electrical Power Research Institute (EPRI) was tasked to provide generic guidelines for the life extension of fossil fuel plant electrical equipment and systems as an alternative to constructing new plants.  They sponsored an in-depth research project and contracted with RTI to develop and produce the guidelines document.

A nuclear reactor's thermal shield was found, during a routine plant inspection, to be seriously cracked and fractured.  The shield is a cylinder of thick steel, which was intended to absorb radiation from the inner core reactor.  The unit was shut down while the shield was removed.

RTI conducted a major investigation of a generating station cable fire and a subsequent substation switchgear and transformer fire, which occurred within days of each other.  The first fire interrupted service to 40,000 customers for up to 3 days, and the second fire left 25,000 of the same customers without service again, this time for up to 12 hours.

There were catastrophic failures of two large generators, one at the Turkey Point Plant, and the other at the Martin Power Plant in Florida. Electrical breakdown and massive electrical arcs destroyed huge laminated iron stator cores, which had to be replaced at great and occasioned even greater expense from the replacement power costs.