TABLE 3.3 Tsunami Wave Height Estimates at the Fukushima Daiichi and Fukushima Daini Plants
|Tsunami Height Estimates (meters relative to O.P.a)|
|Date||Estimate Basis||Fukushima Daiichi||Fukushima Daini|
|1966-1980 (plant permits)||May 22, 1960 earthquake near Valdivia, Chile||3.122 (Units 1-6)||3.122 (Unit 1) 3.690 (Unit 2) 3.705 m (Units 3 and 4)|
|2002||JSCE (2002)b methodology||5.7||5.2|
|2007||Fukushima Prefecture Disaster Prevention Plan||~5.0||~5.0|
|2007||Ibaraki Prefecture Disaster Prevention Plan||4.7||4.7|
|2008||TEPCO trial calculations using fault models for HERP postulated earthquake||8.4-10.2 (Inundation heights: 13.7-15.7)||7.6-8.2 (Inundation height: 15.5)|
|2008||TEPCO trial calculations for Satake et al. (2008) model for Jogan tsunami||8.7-9.2||7.8-8.0|
|2009||JSCE (2002) with updated tidal and bathymetric data||6.1||5.2|
a Onahama Port Construction Standard Surface.
bAn English-language version of this paper was issued in 2006. SOURCES: TEPCO (2012b); TEPCO presentation to the committee, September 6, 2012.
methodology to estimate maximum tsunami wave heights at their plant sites. Based on this new methodology, the maximum tsunami wave height at Fukushima Daiichi was estimated to be O.P. + 5.7 m, over 2.5 m higher than the estimate in the plant’s original permit. The maximum tsunami wave height at Fukushima Daini was estimated to be O.P. + 5.2 m, over 2 m higher than the estimate in the plant’s original permit (Table 3.3).
TEPCO took several countermeasures to protect critical equipment and infrastructure at its plants in response to these new estimates. At Fukushima Daiichi, TEPCO raised the elevations of seawater pumps used to cool