Earthquake & Tsunami impact
Here is some information about the effects of both 3/13 M9 earthquake (東北地方太平洋沖地震) and the subsequent Tsunami over Fukushima Nuclear Power Plants 1 and 2.
Update [5/25] I first created these charts/graphs from a TEPCO document in Japanese, but today TEPCO has published a comprehensive presentation in English including much more data, photos, etc. (link).
Impact from Earthquake
The chart bellow is a compilation of seismic readings obtained by TEPCO at #FNPP1 and #FNPP2 during the quake. As you can see:
- ground acceleration on the East- West direction at #FNPP1 was beyond design specifications in units 2, 3, and 5, pretty close to the limit at units 1 and 6.
- at every other point shaking was bellow specifications.
Even though readings didn’t exceed design specs by so much (maximum is [design+25%] at unit 2), this means that apart from the obvious damage by the Tsunami (see bellow) and H2 explosions, machinery and pipes within the reactor buildings are also likely to be damaged.
Shindo Scale Magnitude
The following chart summarizes ground acceleration based on Japanese seismic intensity scale “shindo” (震度, literally “shaking magnitude”). Colouring is different from previous chart, and based on the scale on the right.
In the following to pictures/diagrams you can see the extension and height of the flooding (about 14-15m high Tsunami), which clearly surpassed the worst case design scenario (5.7 m). I believe both are self-explanatory …
You can find many decent quality pics of the facilities after the tsunami arrival on TEPCO´s press site.