GRAND FALLS GENERATING STATION RESTORATION - AFTER THE GREAT FLOOD OF 2008

摘要

NB Power's 66 MW Grand Falls Generating Station is located on the St. John River in north western New Brunswick. The four unit station went into service in 1928 and has a capacity factor of some 80%. The winter of 2007/2008 saw higher than usual amount of snowfall present in the St. John River Basin above Grand Falls, with the water equivalent in that snow pack some 60% above average. In late April 2008, a heavy rainstorm occurred in the northern reaches of the basin with some areas recording up to 100 mm of rain. The river flow and the resulting water stage reached unprecedented levels. A flood protection retaining wall protecting the Powerhouse was destroyed by the unrelenting water surges. Ultimately the station was flooded with some 2 meters of water over the main Powerhouse floor. This paper describes the project to return the station to commercial operation with all four units returning to service just 5 months after the flood. The project provided the opportunity to upgrade and modernize station ancillary equipment and systems. The Powerhouse and Switchyard were also fortified against future such events.