Minutes of the Annual Meeting of the Power - New York Power ...

even more evident. The program was expanded to include additional overhaul
work, and the cost estimate for the RMNPP portion evolved to about $298
million 7 . This work was necessary to ensure that Hydro Project’s generating
capacity would continue to be available well into the future, particularly in light of
the fact that no serious upgrade to this equipment had been done since it went
into service in 1961. The specific work on the existing generating equipment
included:
- Addressing cavitation erosion of the turbine runners, including complete
penetration of the steel below the lower turbine seal, and avoidance of
further loss of turbine seals (loss of a seal on RMNPP unit 13 had halted
unit operation). This degradation could only be observed when a unit was
disassembled. The replacement turbine runner design provided for a
restored system, with greater resistance to cavitation erosion.
- Addressing cavitation erosion of the head covers. This damage could only
be observed when a unit was disassembled. Repair arc gouging of these
pressure vessels had at times completely penetrated the pressure
retaining structure. Extensive weld repairs were performed.
- Resurfacing wicket gate journals and replacement of gate
bearings/bushings. This work alone would have required unit disassembly
and the associated costs.
- Alignment and balancing of the shafts and rotors.
- Re-establishment of the generator rotor’s ability to center the field poles
and maintain uniform air gaps.
- Replacement of aging original 1961-vintage main transformers.
- Replacement of obsolete excitation and related equipment, for which
spare parts and expertise were difficult to obtain, a continuing trend for old
7 NYPA’s “Robert Moses Niagara Power Plant Upgrade, Prototype Performance and Economic
Analysis Report Presented to the Capital Review Committee” (July 1993) (“1993 RMNPP
Upgrade Analysis”) shows a cost estimate of $300.2 million. This report is available upon
request. Later savings permitted NYPA to adjust the amount to $298 million.
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