A 7.4 aftershock last night at around midnight knocked out power in parts of the Miyagi, Yamagata, Aomori, Iwate, Akita and other Japanese prefectures. While a tsunami warning was issued, but subsequently lifted.
2 of the 3 normal power transmission lines were knocked out at the Onagawa nuclear power plant. However, backup diesel generators are being used, there is no threat to the diesel generators from a large tsunami, and Japanese agencies are saying that there have been no change in radiation levels around the plants.
Therefore, unless the aftershock directly damaged the core or storage tanks, this should not turn into any real problem.
And there are no reports of additional damage to the Fukushima Daiichi or Daini nuclear power complex.
Updates as they come in.
Information courtesy of Kyodo News and NHK News.
