OREANDA-NEWS. December 27, 2012. As Electric Power Development Co., Ltd. (hereinafter, “J-POWER”) previously announced on December 4, the operation of the New No. 2 unit at the Isogo Thermal Power Plant (Location: Isogo-ku, Yokohama, Kanagawa Prefecture; rated unit output: 600MW) was suspended at 10:06 a.m. on December 4, 2012 following detection of a malfunction in the turbine.
Subsequently, the turbine was dismantled and inspected, and other relevant equipment examined, upon which it was found that the malfunction was due to breakage of a rotating blade in a low-pressure turbine.
It was also found that the broken rotating blade then caused damage to other rotating blades in the low-pressure turbine; fragments of the turbine blades then caused cracks in the interior of the condenser*, which allowed an influx of seawater into the pipes, etc.
Currently, J-POWER is investigating the cause of the breakage of the turbine rotating blade, while also working to repair the low-pressure turbine and clean any pipes, etc. through which seawater may have flowed. Going forward, J-POWER will work to ensure the quickest possible restoration of operations, but because time will be needed to manufacture replacements for the damaged rotating blades in the low-pressure turbine, at this point operations are expected to resume sometime in the latter half of May, 2013.
*A heat exchanger used to cool the steam used by the turbine.