According to multiple news agencies (cf. Reuters here, BusinessWeek here, and Nikkei.com, to name just a few), equipment at Toshiba's NAND flash memory fab, theYokkaichi wafer fab located in central Japan, was affected during a power failure. The Yokkaichi wafer fab is, as cited by Reuters, the only location at which Toshiba produces NAND flash memory. As a result of the power failure, Toshiba had to halt production at the fab on Wednesday, December 8. The cause of the power fluctuation is currently cited to have been at the utility level, with power fluctuations confirmed by Chubu Electric Power Company; other major industrial corporations were also forced to halt their operations, according to the same Reuters report.
As of Thursday morning in Japan, December 9, roughly 70% of production at the Toshiba fab was back to normal levels. Toshiba anticipates full return to normal production levels by Friday, December 10.
The impact of this event, according to Toshiba representatives, will likely be a reduction of roughly 20% in NAND flash memory chip shipments during January and February 2011. This reduction will tighten already high-demand NAND flash chips and provide a competitive opportunity for Samsung, in particular. Together, Toshiba and Samsung represent the vast majority of NAND flash production (over 70%).