Some Japanese media, including at least the Daily Yomiuri (www.tinyurl.com/3pqezgd) and NHK, have reported that an analysis carried out for Tepco had predicted in 2008 the possibility of a 10-metre tsunami at Fukushima Daiichi and Daini, but that Tepco failed to act to improve defences.
But Tepco has defended its position. “Our position is that the trial analysis was conducted voluntarily by assuming severe conditions without reasonable wave source models,” a spokesman said.
A 2008 trial analysis using information from the 1896 Meiji-Sanriku tsunami was based on a hypothetical model that did not include a wave source model for the Fukushima prefecture’s Japan trench line, since tsunami had not happened there before. In a separate analysis, Dr Satake of the National Institute of Advanced Industrial Science & Technology had concluded that additional surveys were required to apply the 896 Jogan tsunami analysis to the Fukushima plants.
Tepco’s spokesman added that it had requested the revision of wave source models and tsunami evaluation technology from the Japan Society of Civil Engineers. He also denied media reports that Japanese regulator NISA had instructed it to prepare for larger tsunami.
Tepco has published a timeline of major tsunami preparations at the Fukushima site, which may be seen on the Nuclear Engineering International website, address below.
Regular updates may be found on the website of our sister journal, Nuclear Engineering International, reachable on <www.neimagazine.com> or by clicking on the link in the navigation bar to the left of this page.
The following sites are also posting continuing updates:
<http://www.tepco.co.jp/en/index-e.html>
<http://www.iaea.org/>
<http://www.jaif.or.jp/english/>
<http://bravenewclimate.com/2011/03/15/tepco-reactor-status/>
<http://www.world-nuclear-news.org/>
<http://www.kantei.go.jp/foreign/index-e.html>
